added more robust validation; small changes

Let's have the opposite, and have an example so you don't forget which
is which.

.ackrc

@@ -1,3 +1,6 @@
 --ignore-dir=old/
 --ignore-dir=tmp/
 --ignore-dir=vendor/
+--ignore-dir=releases/
+--ignore-dir=rpmbuild/
+--type-set=mcl:ext:mcl

.editorconfig

@@ -12,8 +12,17 @@ end_of_line = lf
 insert_final_newline = true
 trim_trailing_whitespace = true
 
+[*.sh]
+indent_style = tab
+
 [*.go]
 indent_style = tab
 
 [Makefile]
 indent_style = tab
+
+[*.mcl]
+indent_style = tab
+
+[*.txtar]
+indent_style = tab

.github/FUNDING.yml

@@ -0,0 +1,5 @@
+# You can add one username per supported platform and one custom link.
+custom: "https://paypal.me/purpleidea"
+github: purpleidea
+liberapay: purpleidea
+patreon: purpleidea

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,9 @@
+## Versions:
+
+* mgmt version (eg: `mgmt --version`):
+
+* operating system/distribution (eg: `uname -a`):
+
+* golang version (eg: `go version`):
+
+## Description:

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,47 @@
+## Tips:
+
+* please read the style guide before submitting your patch:
+[docs/style-guide.md](../docs/style-guide.md)
+
+* commit message titles must be in the form:
+
+```topic: Capitalized message with no trailing period```
+
+or:
+
+```topic, topic2: Capitalized message with no trailing period```
+
+* golang code must be formatted according to the standard, please run:
+
+```
+make gofmt		# formats the entire project correctly
+```
+
+or format a single golang file correctly:
+
+```
+gofmt -w yourcode.go
+```
+
+* please rebase your patch against current git master:
+
+```
+git checkout master
+git pull origin master
+git checkout your-feature
+git rebase master
+git push your-remote your-feature
+hub pull-request	# or submit with the github web ui
+```
+
+* after a patch review, please ping @purpleidea so we know to re-review:
+
+```
+# make changes based on reviews...
+git add -p		# add new changes
+git commit --amend	# combine with existing commit
+git push your-remote your-feature -f
+# now ping @purpleidea in the github PR since it doesn't notify us automatically
+```
+
+## Thanks for contributing to mgmt and welcome to the team!

.github/settings.yml

@@ -0,0 +1,98 @@
+# These settings are synced to GitHub by https://probot.github.io/apps/settings/
+
+repository:
+  # See https://developer.github.com/v3/repos/#edit for all available settings.
+
+  # The name of the repository. Changing this will rename the repository
+  name: mgmt
+
+  # A short description of the repository that will show up on GitHub
+  description: Next generation distributed, event-driven, parallel config management!
+
+  # A URL with more information about the repository
+  homepage: https://purpleidea.com/tags/mgmtconfig/
+
+  # A comma-separated list of topics to set on the repository
+  topics: golang, go, configuration-management, config-management, devops, etcd, distributed-systems, graph-theory, choreography
+
+  # Either `true` to make the repository private, or `false` to make it public.
+  private: false
+
+  # Either `true` to enable issues for this repository, `false` to disable them.
+  has_issues: true
+
+  # Either `true` to enable projects for this repository, or `false` to disable them.
+  # If projects are disabled for the organization, passing `true` will cause an API error.
+  has_projects: false
+
+  # Either `true` to enable the wiki for this repository, `false` to disable it.
+  has_wiki: false
+
+  # Either `true` to enable downloads for this repository, `false` to disable them.
+  has_downloads: true
+
+  # Updates the default branch for this repository.
+  default_branch: master
+
+  # Either `true` to allow squash-merging pull requests, or `false` to prevent
+  # squash-merging.
+  allow_squash_merge: false
+
+  # Either `true` to allow merging pull requests with a merge commit, or `false`
+  # to prevent merging pull requests with merge commits.
+  allow_merge_commit: false
+
+  # Either `true` to allow rebase-merging pull requests, or `false` to prevent
+  # rebase-merging.
+  allow_rebase_merge: true
+
+# Labels: define labels for Issues and Pull Requests (in alphabetical order)
+labels:
+  - name: bug
+    color: fc2929
+  - name: confirmed
+    color: d93f0b
+  - name: design
+    color: 5319e7
+  - name: duplicate
+    color: cccccc
+  - name: enhancement
+    color: 84b6eb
+  - name: good first issue
+    color: 7057ff
+  - name: help wanted
+    color: 159818
+  - name: invalid
+    color: e6e6e6
+  - name: mgmtlove
+    color: e11d21
+  - name: question
+    color: cc317c
+  - name: needinfo
+    color: fbca04
+  - name: wontfix
+    color: ffffff
+#  - name: first-timers-only
+#    # include the old name to rename an existing label
+#    oldname: Help Wanted
+
+# Collaborators: give specific users access to this repository.
+#collaborators:
+#  - username: purpleidea
+#    # Note: Only valid on organization-owned repositories.
+#    # The permission to grant the collaborator. Can be one of:
+#    # * `pull` - can pull, but not push to or administer this repository.
+#    # * `push` - can pull and push, but not administer this repository.
+#    # * `admin` - can pull, push and administer this repository.
+#    permission: push
+
+#  - username: hubot
+#    permission: pull
+
+# NOTE: The APIs needed for teams are not supported yet by GitHub Apps
+# https://developer.github.com/v3/apps/available-endpoints/
+#teams:
+#  - name: core
+#    permission: admin
+#  - name: docs
+#    permission: push

.github/workflows/test.yaml

@@ -0,0 +1,68 @@
+# Docs: https://help.github.com/en/articles/workflow-syntax-for-github-actions
+
+# If the name is omitted, it uses the filename instead.
+#name: Test
+on:
+  # Run on all pull requests.
+  pull_request:
+    #branches:
+    #- master
+  # Run on all pushes.
+  push:
+  # Run daily at 4am.
+  schedule:
+  - cron: 0 4 * * *
+
+jobs:
+  maketest:
+    name: Test (${{ matrix.test_block }}) on ${{ matrix.os }} with golang ${{ matrix.golang_version }}
+    runs-on: ${{ matrix.os }}
+    env:
+      GOPATH: /home/runner/work/mgmt/mgmt/go
+    strategy:
+      matrix:
+        # TODO: Add tip when it's supported: https://github.com/actions/setup-go/issues/21
+        os:
+          - ubuntu-latest
+          # macos tests are currently failing in CI
+          #- macos-latest
+        golang_version:
+          # TODO: add 1.24.x and tip
+          # minimum required and latest published go_version
+          - "1.23"
+        test_block:
+          - basic
+          - shell
+          - race
+      fail-fast: false
+
+    steps:
+      # Do not shallow fetch. The path can't be absolute, so we need to move it
+      # to the expected location later.
+      - name: Clone mgmt
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+          fetch-depth: 0
+          path: ./go/src/github.com/purpleidea/mgmt
+
+      - name: Install Go ${{ matrix.golang_version }}
+        uses: actions/setup-go@v4
+        with:
+          go-version: ${{ matrix.golang_version }}
+
+      # Install & configure ruby, fixes gem permissions error
+      - name: Install Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: head
+
+      - name: Install dependencies
+        working-directory: ./go/src/github.com/purpleidea/mgmt
+        run: |
+          make deps
+
+      - name: Run test
+        working-directory: ./go/src/github.com/purpleidea/mgmt
+        run: |
+          TEST_BLOCK="${{ matrix.test_block }}" make test

.gitignore

@@ -2,11 +2,25 @@
 .omv/
 .ssh/
 .vagrant/
-mgmt-documentation.pdf
+.envrc
 old/
 tmp/
+/vendor/
+*WIP
 *_stringer.go
-mgmt
-mgmt.static
+/mgmt
+/mgmt.static
+# crossbuild artifacts
+/build/mgmt-*
 mgmt.iml
-rpmbuild/
+/rpmbuild/
+/releases/
+/repository/
+/pprof/
+/sites/
+# vim swap files
+.*.sw[op]
+# prevent `echo foo 2>1` typo errors by making this file read-only
+1
+# allow users to keep some junk files around
+*.wip

.gitmodules

@@ -1,15 +0,0 @@
-[submodule "vendor/github.com/coreos/etcd"]
-	path = vendor/github.com/coreos/etcd
-	url = https://github.com/coreos/etcd/
-[submodule "vendor/google.golang.org/grpc"]
-	path = vendor/google.golang.org/grpc
-	url = https://github.com/grpc/grpc-go
-[submodule "vendor/github.com/grpc-ecosystem/grpc-gateway"]
-	path = vendor/github.com/grpc-ecosystem/grpc-gateway
-	url = https://github.com/grpc-ecosystem/grpc-gateway
-[submodule "vendor/gopkg.in/fsnotify.v1"]
-	path = vendor/gopkg.in/fsnotify.v1
-	url = https://gopkg.in/fsnotify.v1
-[submodule "vendor/github.com/purpleidea/go-systemd"]
-	path = vendor/github.com/purpleidea/go-systemd
-	url = https://github.com/purpleidea/go-systemd

.lycheeignore

@@ -0,0 +1,3 @@
+# list URLs that should be excluded for lychee link checher
+https://roidelapluie.be
+https://github.com/purpleidea/mgmt/commit

.travis.yml

@@ -1,28 +0,0 @@
-language: go
-go:
-  - 1.6
-  - 1.7
-  - tip
-sudo: true
-dist: trusty
-before_install: 'git fetch --unshallow'
-install: 'make deps'
-script: 'make test'
-matrix:
-  fast_finish: true
-  allow_failures:
-    - go: tip
-    - go: 1.7
-notifications:
-  irc:
-    channels:
-      - "irc.freenode.net#mgmtconfig"
-    template:
-      - "%{repository} (%{commit}: %{author}): %{message}"
-      - "More info : %{build_url}"
-    on_success: always
-    on_failure: always
-    use_notice: false
-    skip_join: false
-  email:
-    - travis-ci@shubin.ca

AUTHORS

@@ -1,8 +1,14 @@
 This is a list of authors/contributors to the mgmt project.
-If you're a contributor, please send a patch with your name.
+If you're a core contributor, we might ask you to send a patch with your name.
 If you appreciate the work of one of the contributors, thank them a beverage!
 For a more exhaustive list please run: git log --format='%aN' | sort -u
 This list is sorted alphabetically by first name.
 
+Felix Frank
 James Shubin
+Joe Groocock
+Johan Bloemberg
+Jonathan Gold
+Julien Pivotto
 Paul Morgan
+Samuel Gélineau

COPYING

@@ -1,21 +1,23 @@
-                    GNU AFFERO GENERAL PUBLIC LICENSE
-                       Version 3, 19 November 2007
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
 
- Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
  Everyone is permitted to copy and distribute verbatim copies
  of this license document, but changing it is not allowed.
 
                             Preamble
 
-  The GNU Affero General Public License is a free, copyleft license for
-software and other kinds of works, specifically designed to ensure
-cooperation with the community in the case of network server software.
+  The GNU General Public License is a free, copyleft license for
+software and other kinds of works.
 
   The licenses for most software and other practical works are designed
 to take away your freedom to share and change the works.  By contrast,
-our General Public Licenses are intended to guarantee your freedom to
+the GNU General Public License is intended to guarantee your freedom to
 share and change all versions of a program--to make sure it remains free
-software for all its users.
+software for all its users.  We, the Free Software Foundation, use the
+GNU General Public License for most of our software; it applies also to
+any other work released this way by its authors.  You can apply it to
+your programs, too.
 
   When we speak of free software, we are referring to freedom, not
 price.  Our General Public Licenses are designed to make sure that you
@@ -24,34 +26,44 @@ them if you wish), that you receive source code or can get it if you
 want it, that you can change the software or use pieces of it in new
 free programs, and that you know you can do these things.
 
-  Developers that use our General Public Licenses protect your rights
-with two steps: (1) assert copyright on the software, and (2) offer
-you this License which gives you legal permission to copy, distribute
-and/or modify the software.
+  To protect your rights, we need to prevent others from denying you
+these rights or asking you to surrender the rights.  Therefore, you have
+certain responsibilities if you distribute copies of the software, or if
+you modify it: responsibilities to respect the freedom of others.
 
-  A secondary benefit of defending all users' freedom is that
-improvements made in alternate versions of the program, if they
-receive widespread use, become available for other developers to
-incorporate.  Many developers of free software are heartened and
-encouraged by the resulting cooperation.  However, in the case of
-software used on network servers, this result may fail to come about.
-The GNU General Public License permits making a modified version and
-letting the public access it on a server without ever releasing its
-source code to the public.
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must pass on to the recipients the same
+freedoms that you received.  You must make sure that they, too, receive
+or can get the source code.  And you must show them these terms so they
+know their rights.
 
-  The GNU Affero General Public License is designed specifically to
-ensure that, in such cases, the modified source code becomes available
-to the community.  It requires the operator of a network server to
-provide the source code of the modified version running there to the
-users of that server.  Therefore, public use of a modified version, on
-a publicly accessible server, gives the public access to the source
-code of the modified version.
+  Developers that use the GNU GPL protect your rights with two steps:
+(1) assert copyright on the software, and (2) offer you this License
+giving you legal permission to copy, distribute and/or modify it.
 
-  An older license, called the Affero General Public License and
-published by Affero, was designed to accomplish similar goals.  This is
-a different license, not a version of the Affero GPL, but Affero has
-released a new version of the Affero GPL which permits relicensing under
-this license.
+  For the developers' and authors' protection, the GPL clearly explains
+that there is no warranty for this free software.  For both users' and
+authors' sake, the GPL requires that modified versions be marked as
+changed, so that their problems will not be attributed erroneously to
+authors of previous versions.
+
+  Some devices are designed to deny users access to install or run
+modified versions of the software inside them, although the manufacturer
+can do so.  This is fundamentally incompatible with the aim of
+protecting users' freedom to change the software.  The systematic
+pattern of such abuse occurs in the area of products for individuals to
+use, which is precisely where it is most unacceptable.  Therefore, we
+have designed this version of the GPL to prohibit the practice for those
+products.  If such problems arise substantially in other domains, we
+stand ready to extend this provision to those domains in future versions
+of the GPL, as needed to protect the freedom of users.
+
+  Finally, every program is threatened constantly by software patents.
+States should not allow patents to restrict development and use of
+software on general-purpose computers, but in those that do, we wish to
+avoid the special danger that patents applied to a free program could
+make it effectively proprietary.  To prevent this, the GPL assures that
+patents cannot be used to render the program non-free.
 
   The precise terms and conditions for copying, distribution and
 modification follow.
@@ -60,7 +72,7 @@ modification follow.
 
   0. Definitions.
 
-  "This License" refers to version 3 of the GNU Affero General Public License.
+  "This License" refers to version 3 of the GNU General Public License.
 
   "Copyright" also means copyright-like laws that apply to other kinds of
 works, such as semiconductor masks.
@@ -537,45 +549,35 @@ to collect a royalty for further conveying from those to whom you convey
 the Program, the only way you could satisfy both those terms and this
 License would be to refrain entirely from conveying the Program.
 
-  13. Remote Network Interaction; Use with the GNU General Public License.
-
-  Notwithstanding any other provision of this License, if you modify the
-Program, your modified version must prominently offer all users
-interacting with it remotely through a computer network (if your version
-supports such interaction) an opportunity to receive the Corresponding
-Source of your version by providing access to the Corresponding Source
-from a network server at no charge, through some standard or customary
-means of facilitating copying of software.  This Corresponding Source
-shall include the Corresponding Source for any work covered by version 3
-of the GNU General Public License that is incorporated pursuant to the
-following paragraph.
+  13. Use with the GNU Affero General Public License.
 
   Notwithstanding any other provision of this License, you have
 permission to link or combine any covered work with a work licensed
-under version 3 of the GNU General Public License into a single
+under version 3 of the GNU Affero General Public License into a single
 combined work, and to convey the resulting work.  The terms of this
 License will continue to apply to the part which is the covered work,
-but the work with which it is combined will remain governed by version
-3 of the GNU General Public License.
+but the special requirements of the GNU Affero General Public License,
+section 13, concerning interaction through a network will apply to the
+combination as such.
 
   14. Revised Versions of this License.
 
   The Free Software Foundation may publish revised and/or new versions of
-the GNU Affero General Public License from time to time.  Such new versions
-will be similar in spirit to the present version, but may differ in detail to
+the GNU General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
 address new problems or concerns.
 
   Each version is given a distinguishing version number.  If the
-Program specifies that a certain numbered version of the GNU Affero General
+Program specifies that a certain numbered version of the GNU General
 Public License "or any later version" applies to it, you have the
 option of following the terms and conditions either of that numbered
 version or of any later version published by the Free Software
 Foundation.  If the Program does not specify a version number of the
-GNU Affero General Public License, you may choose any version ever published
+GNU General Public License, you may choose any version ever published
 by the Free Software Foundation.
 
   If the Program specifies that a proxy can decide which future
-versions of the GNU Affero General Public License can be used, that proxy's
+versions of the GNU General Public License can be used, that proxy's
 public statement of acceptance of a version permanently authorizes you
 to choose that version for the Program.
 
@@ -633,29 +635,40 @@ the "copyright" line and a pointer to where the full notice is found.
     Copyright (C) <year>  <name of author>
 
     This program is free software: you can redistribute it and/or modify
-    it under the terms of the GNU Affero General Public License as published by
+    it under the terms of the GNU General Public License as published by
     the Free Software Foundation, either version 3 of the License, or
     (at your option) any later version.
 
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU Affero General Public License for more details.
+    GNU General Public License for more details.
 
-    You should have received a copy of the GNU Affero General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 Also add information on how to contact you by electronic and paper mail.
 
-  If your software can interact with users remotely through a computer
-network, you should also make sure that it provides a way for users to
-get its source.  For example, if your program is a web application, its
-interface could display a "Source" link that leads users to an archive
-of the code.  There are many ways you could offer source, and different
-solutions will be better for different programs; see section 13 for the
-specific requirements.
+  If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+    <program>  Copyright (C) <year>  <name of author>
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
 
   You should also get your employer (if you work as a programmer) or school,
 if any, to sign a "copyright disclaimer" for the program, if necessary.
-For more information on this, and how to apply and follow the GNU AGPL, see
-<http://www.gnu.org/licenses/>.
+For more information on this, and how to apply and follow the GNU GPL, see
+<https://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+into proprietary programs.  If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.  But first, please read
+<https://www.gnu.org/philosophy/why-not-lgpl.html>.

COPYRIGHT

@@ -1,16 +1,28 @@
 Mgmt
-Copyright (C) 2013-2016+ James Shubin and the project contributors
+Copyright (C) James Shubin and the project contributors
 Written by James Shubin <james@shubin.ca> and the project contributors
 
 This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU Affero General Public License as published by
+it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.
 
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU Affero General Public License for more details.
+GNU General Public License for more details.
 
-You should have received a copy of the GNU Affero General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+Additional permission under GNU GPL version 3 section 7
+
+If you modify this program, or any covered work, by linking or combining it
+with embedded mcl code and modules (and that the embedded mcl code and
+modules which link with this program, contain a copy of their source code in
+the authoritative form) containing parts covered by the terms of any other
+license, the licensors of this program grant you additional permission to
+convey the resulting work. Furthermore, the licensors of this program grant
+the original author, James Shubin, additional permission to update this
+additional permission if he deems it necessary to achieve the goals of this
+additional permission.

DOCUMENTATION.md

@@ -1,564 +0,0 @@
-#mgmt
-
-<!--
-Mgmt
-Copyright (C) 2013-2016+ James Shubin and the project contributors
-Written by James Shubin <james@shubin.ca> and the project contributors
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU Affero General Public License as published by
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU Affero General Public License for more details.
-
-You should have received a copy of the GNU Affero General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
--->
-
-##mgmt by [James](https://ttboj.wordpress.com/)
-####Available from:
-####[https://github.com/purpleidea/mgmt/](https://github.com/purpleidea/mgmt/)
-
-####This documentation is available in: [Markdown](https://github.com/purpleidea/mgmt/blob/master/DOCUMENTATION.md) or [PDF](https://pdfdoc-purpleidea.rhcloud.com/pdf/https://github.com/purpleidea/mgmt/blob/master/DOCUMENTATION.md) format.
-
-####Table of Contents
-
-1. [Overview](#overview)
-2. [Project description - What the project does](#project-description)
-3. [Setup - Getting started with mgmt](#setup)
-4. [Features - All things mgmt can do](#features)
-	* [Autoedges - Automatic resource relationships](#autoedges)
-	* [Autogrouping - Automatic resource grouping](#autogrouping)
-	* [Automatic clustering - Automatic cluster management](#automatic-clustering)
-	* [Remote mode - Remote "agent-less" execution](#remote-agent-less-mode)
-	* [Puppet support - write manifest code for mgmt](#puppet-support)
-5. [Resources - All built-in primitives](#resources)
-6. [Usage/FAQ - Notes on usage and frequently asked questions](#usage-and-frequently-asked-questions)
-7. [Reference - Detailed reference](#reference)
-	* [Meta parameters](#meta-parameters)
-	* [Graph definition file](#graph-definition-file)
-	* [Command line](#command-line)
-8. [Examples - Example configurations](#examples)
-9. [Development - Background on module development and reporting bugs](#development)
-10. [Authors - Authors and contact information](#authors)
-
-##Overview
-
-The `mgmt` tool is a next generation config management prototype. It's not yet
-ready for production, but we hope to get there soon. Get involved today!
-
-##Project Description
-
-The mgmt tool is a distributed, event driven, config management tool, that
-supports parallel execution, and librarification to be used as the management
-foundation in and for, new and existing software.
-
-For more information, you may like to read some blog posts from the author:
-
-* [Next generation config mgmt](https://ttboj.wordpress.com/2016/01/18/next-generation-configuration-mgmt/)
-* [Automatic edges in mgmt](https://ttboj.wordpress.com/2016/03/14/automatic-edges-in-mgmt/)
-* [Automatic grouping in mgmt](https://ttboj.wordpress.com/2016/03/30/automatic-grouping-in-mgmt/)
-* [Automatic clustering in mgmt](https://ttboj.wordpress.com/2016/06/20/automatic-clustering-in-mgmt/)
-
-There is also an [introductory video](http://meetings-archive.debian.net/pub/debian-meetings/2016/debconf16/Next_Generation_Config_Mgmt.webm) available.
-Older videos and other material [is available](https://github.com/purpleidea/mgmt/#on-the-web).
-
-##Setup
-
-During this prototype phase, the tool can be run out of the source directory.
-You'll probably want to use ```./run.sh run --yaml examples/graph1.yaml``` to
-get started. Beware that this _can_ cause data loss. Understand what you're
-doing first, or perform these actions in a virtual environment such as the one
-provided by [Oh-My-Vagrant](https://github.com/purpleidea/oh-my-vagrant).
-
-##Features
-
-This section details the numerous features of mgmt and some caveats you might
-need to be aware of.
-
-###Autoedges
-
-Automatic edges, or AutoEdges, is the mechanism in mgmt by which it will
-automatically create dependencies for you between resources. For example,
-since mgmt can discover which files are installed by a package it will
-automatically ensure that any file resource you declare that matches a
-file installed by your package resource will only be processed after the
-package is installed.
-
-####Controlling autoedges
-
-Though autoedges is likely to be very helpful and avoid you having to declare
-all dependencies explicitly, there are cases where this behaviour is
-undesirable.
-
-Some distributions allow package installations to automatically start the
-service they ship. This can be problematic in the case of packages like MySQL
-as there are configuration options that need to be set before MySQL is ever
-started for the first time (or you'll need to wipe the data directory). In
-order to handle this situation you can disable autoedges per resource and
-explicitly declare that you want `my.cnf` to be written to disk before the
-installation of the `mysql-server` package.
-
-You can disable autoedges for a resource by setting the `autoedge` key on
-the meta attributes of that resource to `false`.
-
-####Blog post
-
-You can read the introductory blog post about this topic here:
-[https://ttboj.wordpress.com/2016/03/14/automatic-edges-in-mgmt/](https://ttboj.wordpress.com/2016/03/14/automatic-edges-in-mgmt/)
-
-###Autogrouping
-
-Automatic grouping or AutoGroup is the mechanism in mgmt by which it will
-automatically group multiple resource vertices into a single one. This is
-particularly useful for grouping multiple package resources into a single
-resource, since the multiple installations can happen together in a single
-transaction, which saves a lot of time because package resources typically have
-a large fixed cost to running (downloading and verifying the package repo) and
-if they are grouped they share this fixed cost. This grouping feature can be
-used for other use cases too.
-
-You can disable autogrouping for a resource by setting the `autogroup` key on
-the meta attributes of that resource to `false`.
-
-####Blog post
-
-You can read the introductory blog post about this topic here:
-[https://ttboj.wordpress.com/2016/03/30/automatic-grouping-in-mgmt/](https://ttboj.wordpress.com/2016/03/30/automatic-grouping-in-mgmt/)
-
-###Automatic clustering
-
-Automatic clustering is a feature by which mgmt automatically builds, scales,
-and manages the embedded etcd cluster which is compiled into mgmt itself. It is
-quite helpful for rapidly bootstrapping clusters and avoiding the extra work to
-setup etcd.
-
-If you prefer to avoid this feature. you can always opt to use an existing etcd
-cluster that is managed separately from mgmt by pointing your mgmt agents at it
-with the `--seeds` variable.
-
-####Blog post
-
-You can read the introductory blog post about this topic here:
-[https://ttboj.wordpress.com/2016/06/20/automatic-clustering-in-mgmt/](https://ttboj.wordpress.com/2016/06/20/automatic-clustering-in-mgmt/)
-
-###Remote ("agent-less") mode
-
-Remote mode is a special mode that lets you kick off mgmt runs on one or more
-remote machines which are only accessible via SSH. In this mode the initiating
-host connects over SSH, copies over the `mgmt` binary, opens an SSH tunnel, and
-runs the remote program while simultaneously passing the etcd traffic back
-through the tunnel so that the initiators etcd cluster can be used to exchange
-resource data.
-
-The interesting benefit of this architecture is that multiple hosts which can't
-connect directly use the initiator to pass the important traffic through to each
-other. Once the cluster has converged all the remote programs can shutdown
-leaving no residual agent.
-
-This mode can also be useful for bootstrapping a new host where you'd like to
-have the service run continuously and as part of an mgmt cluster normally.
-
-In particular, when combined with the `--converged-timeout` parameter, the
-entire set of running mgmt agents will need to all simultaneously converge for
-the group to exit. This is particularly useful for bootstrapping new clusters
-which need to exchange information that is only available at run time.
-
-####Blog post
-
-You can read the introductory blog post about this topic here:
-[https://ttboj.wordpress.com/2016/10/07/remote-execution-in-mgmt/](https://ttboj.wordpress.com/2016/10/07/remote-execution-in-mgmt/)
-
-###Puppet support
-
-You can supply a Puppet manifest instead of creating the (YAML) graph manually.
-Puppet must be installed and in `mgmt`'s search path. You also need the
-[ffrank-mgmtgraph Puppet module](https://forge.puppet.com/ffrank/mgmtgraph).
-
-Invoke `mgmt` with the `--puppet` switch, which supports 3 variants:
-
-1. Request the configuration from the Puppet Master (like `puppet agent` does)
-
-        mgmt run --puppet agent
-
-2. Compile a local manifest file (like `puppet apply`)
-
-        mgmt run --puppet /path/to/my/manifest.pp
-
-3. Compile an ad hoc manifest from the commandline (like `puppet apply -e`)
-
-        mgmt run --puppet 'file { "/etc/ntp.conf": ensure => file }'
-
-For more details and caveats see [Puppet.md](Puppet.md).
-
-####Blog post
-
-An introductory post on the Puppet support is on
-[Felix's blog](http://ffrank.github.io/features/2016/06/19/puppet-powered-mgmt/).
-
-##Resources
-
-This section lists all the built-in resources and their properties. The
-resource primitives in `mgmt` are typically more powerful than resources in
-other configuration management systems because they can be event based which
-lets them respond in real-time to converge to the desired state. This property
-allows you to build more complex resources that you probably hadn't considered
-in the past.
-
-In addition to the resource specific properties, there are resource properties
-(otherwise known as parameters) which can apply to every resource. These are
-called [meta parameters](#meta-parameters) and are listed separately. Certain
-meta parameters aren't very useful when combined with certain resources, but
-in general, it should be fairly obvious, such as when combining the `noop` meta
-parameter with the [Noop](#Noop) resource.
-
-* [Exec](#Exec): Execute shell commands on the system.
-* [File](#File): Manage files and directories.
-* [Hostname](#Hostname): Manages the hostname on the system.
-* [Msg](#Msg): Send log messages.
-* [Noop](#Noop): A simple resource that does nothing.
-* [Nspawn](#Nspawn): Manage systemd-machined nspawn containers.
-* [Password](#Password): Create random password strings.
-* [Pkg](#Pkg):  Manage system packages with PackageKit.
-* [Svc](#Svc): Manage system systemd services.
-* [Timer](#Timer): Manage system systemd services.
-* [Virt](#Virt): Manage virtual machines with libvirt.
-
-###Exec
-
-The exec resource can execute commands on your system.
-
-###File
-
-The file resource manages files and directories. In `mgmt`, directories are
-identified by a trailing slash in their path name. File have no such slash.
-
-####Path
-
-The path property specifies the file or directory that we are managing.
-
-####Content
-
-The content property is a string that specifies the desired file contents.
-
-####Source
-
-The source property points to a source file or directory path that we wish to
-copy over and use as the desired contents for our resource.
-
-####State
-
-The state property describes the action we'd like to apply for the resource. The
-possible values are: `exists` and `absent`.
-
-####Recurse
-
-The recurse property limits whether file resource operations should recurse into
-and monitor directory contents with a depth greater than one.
-
-####Force
-
-The force property is required if we want the file resource to be able to change
-a file into a directory or vice-versa. If such a change is needed, but the force
-property is not set to `true`, then this file resource will error.
-
-###Hostname
-
-The hostname resource manages static, transient/dynamic and pretty hostnames
-on the system and watches them for changes.
-
-#### static_hostname
-The static hostname is the one configured in /etc/hostname or a similar
-file.
-It is chosen by the local user. It is not always in sync with the current
-host name as returned by the gethostname() system call.
-
-#### transient_hostname
-The transient / dynamic hostname is the one configured via the kernel's
-sethostbyname().
-It can be different from the static hostname in case DHCP or mDNS have been
-configured to change the name based on network information.
-
-#### pretty_hostname
-The pretty hostname is a free-form UTF8 host name for presentation to the user.
-
-#### hostname
-Hostname is the fallback value for all 3 fields above, if only `hostname` is
-specified, it will set all 3 fields to this value.
-
-###Msg
-
-The msg resource sends messages to the main log, or an external service such
-as systemd's journal.
-
-###Noop
-
-The noop resource does absolutely nothing. It does have some utility in testing
-`mgmt` and also as a placeholder in the resource graph.
-
-###Nspawn
-
-The nspawn resource is used to manage systemd-machined style containers.
-
-###Password
-
-The password resource can generate a random string to be used as a password. It
-will re-generate the password if it receives a refresh notification.
-
-###Pkg
-
-The pkg resource is used to manage system packages. This resource works on many
-different distributions because it uses the underlying packagekit facility which
-supports different backends for different environments. This ensures that we
-have great Debian (deb/dpkg) and Fedora (rpm/dnf) support simultaneously.
-
-###Svc
-
-The service resource is still very WIP. Please help us my improving it!
-
-###Timer
-
-This resource needs better documentation. Please help us my improving it!
-
-###Virt
-
-The virt resource can manage virtual machines via libvirt.
-
-##Usage and frequently asked questions
-(Send your questions as a patch to this FAQ! I'll review it, merge it, and
-respond by commit with the answer.)
-
-###Why did you start this project?
-
-I wanted a next generation config management solution that didn't have all of
-the design flaws or limitations that the current generation of tools do, and no
-tool existed!
-
-###Why did you use etcd? What about consul?
-
-Etcd and consul are both written in golang, which made them the top two
-contenders for my prototype. Ultimately a choice had to be made, and etcd was
-chosen, but it was also somewhat arbitrary. If there is available interest,
-good reasoning, *and* patches, then we would consider either switching or
-supporting both, but this is not a high priority at this time.
-
-###Can I use an existing etcd cluster instead of the automatic embedded servers?
-
-Yes, it's possible to use an existing etcd cluster instead of the automatic,
-elastic embedded etcd servers. To do so, simply point to the cluster with the
-`--seeds` variable, the same way you would if you were seeding a new member to
-an existing mgmt cluster.
-
-The downside to this approach is that you won't benefit from the automatic
-elastic nature of the embedded etcd servers, and that you're responsible if you
-accidentally break your etcd cluster, or if you use an unsupported version.
-
-###What does the error message about an inconsistent dataDir mean?
-
-If you get an error message similar to:
-
-```
-Etcd: Connect: CtxError...
-Etcd: CtxError: Reason: CtxDelayErr(5s): No endpoints available yet!
-Etcd: Connect: Endpoints: []
-Etcd: The dataDir (/var/lib/mgmt/etcd) might be inconsistent or corrupt.
-```
-
-This happens when there are a series of fatal connect errors in a row. This can
-happen when you start `mgmt` using a dataDir that doesn't correspond to the
-current cluster view. As a result, the embedded etcd server never finishes
-starting up, and as a result, a default endpoint never gets added. The solution
-is to either reconcile the mistake, and if there is no important data saved, you
-can remove the etcd dataDir. This is typically `/var/lib/mgmt/etcd/member/`.
-
-###Why do resources have both a `Compare` method and an `IFF` (on the UID) method?
-
-The `Compare()` methods are for determining if two resources are effectively the
-same, which is used to make graph change delta's efficient. This is when we want
-to change from the current running graph to a new graph, but preserve the common
-vertices. Since we want to make this process efficient, we only update the parts
-that are different, and leave everything else alone. This `Compare()` method can
-tell us if two resources are the same.
-
-The `IFF()` method is part of the whole UID system, which is for discerning if a
-resource meets the requirements another expects for an automatic edge. This is
-because the automatic edge system assumes a unified UID pattern to test for
-equality. In the future it might be helpful or sane to merge the two similar
-comparison functions although for now they are separate because they are
-actually answer different questions.
-
-###Did you know that there is a band named `MGMT`?
-
-I didn't realize this when naming the project, and it is accidental. After much
-anguishing, I chose the name because it was short and I thought it was
-appropriately descriptive. If you need a less ambiguous search term or phrase,
-you can try using `mgmtconfig` or `mgmt config`.
-
-###You didn't answer my question, or I have a question!
-
-It's best to ask on [IRC](https://webchat.freenode.net/?channels=#mgmtconfig)
-to see if someone can help you. Once we get a big enough community going, we'll
-add a mailing list. If you don't get any response from the above, you can
-contact me through my [technical blog](https://ttboj.wordpress.com/contact/)
-and I'll do my best to help. If you have a good question, please add it as a
-patch to this documentation. I'll merge your question, and add a patch with the
-answer!
-
-##Reference
-Please note that there are a number of undocumented options. For more
-information on these options, please view the source at:
-[https://github.com/purpleidea/mgmt/](https://github.com/purpleidea/mgmt/).
-If you feel that a well used option needs documenting here, please patch it!
-
-###Overview of reference
-* [Meta parameters](#meta-parameters): List of available resource meta parameters.
-* [Graph definition file](#graph-definition-file): Main graph definition file.
-* [Command line](#command-line): Command line parameters.
-
-###Meta parameters
-These meta parameters are special parameters (or properties) which can apply to
-any resource. The usefulness of doing so will depend on the particular meta
-parameter and resource combination.
-
-####AutoEdge
-Boolean. Should we generate auto edges for this resource?
-
-####AutoGroup
-Boolean. Should we attempt to automatically group this resource with others?
-
-####Noop
-Boolean. Should the Apply portion of the CheckApply method of the resource
-make any changes? Noop is a concatenation of no-operation.
-
-####Retry
-Integer. The number of times to retry running the resource on error. Use -1 for
-infinite. This currently applies for both the Watch operation (which can fail)
-and for the CheckApply operation. While they could have separate values, I've
-decided to use the same ones for both until there's a proper reason to want to
-do something differently for the Watch errors.
-
-####Delay
-Integer. Number of milliseconds to wait between retries. The same value is
-shared between the Watch and CheckApply retries. This currently applies for both
-the Watch operation (which can fail) and for the CheckApply operation. While
-they could have separate values, I've decided to use the same ones for both
-until there's a proper reason to want to do something differently for the Watch
-errors.
-
-###Graph definition file
-graph.yaml is the compiled graph definition file. The format is currently
-undocumented, but by looking through the [examples/](https://github.com/purpleidea/mgmt/tree/master/examples)
-you can probably figure out most of it, as it's fairly intuitive.
-
-###Command line
-The main interface to the `mgmt` tool is the command line. For the most recent
-documentation, please run `mgmt --help`.
-
-####`--yaml <graph.yaml>`
-Point to a graph file to run.
-
-####`--converged-timeout <seconds>`
-Exit if the machine has converged for approximately this many seconds.
-
-####`--max-runtime <seconds>`
-Exit when the agent has run for approximately this many seconds. This is not
-generally recommended, but may be useful for users who know what they're doing.
-
-####`--noop`
-Globally force all resources into no-op mode. This also disables the export to
-etcd functionality, but does not disable resource collection, however all
-resources that are collected will have their individual noop settings set.
-
-####`--remote <graph.yaml>`
-Point to a graph file to run on the remote host specified within. This parameter
-can be used multiple times if you'd like to remotely run on multiple hosts in
-parallel.
-
-####`--allow-interactive`
-Allow interactive prompting for SSH passwords if there is no authentication
-method that works.
-
-####`--ssh-priv-id-rsa`
-Specify the path for finding SSH keys. This defaults to `~/.ssh/id_rsa`. To
-never use this method of authentication, set this to the empty string.
-
-####`--cconns`
-The maximum number of concurrent remote ssh connections to run. This defaults
-to `0`, which means unlimited.
-
-####`--no-caching`
-Don't allow remote caching of the remote execution binary. This will require
-the binary to be copied over for every remote execution, but it limits the
-likelihood that there is leftover information from the configuration process.
-
-####`--prefix <path>`
-Specify a path to a custom working directory prefix. This directory will get
-created if it does not exist. This usually defaults to `/var/lib/mgmt/`. This
-can't be combined with the `--tmp-prefix` option. It can be combined with the
-`--allow-tmp-prefix` option.
-
-####`--tmp-prefix`
-If this option is specified, a temporary prefix will be used instead of the
-default prefix. This can't be combined with the `--prefix` option.
-
-####`--allow-tmp-prefix`
-If this option is specified, we will attempt to fall back to a temporary prefix
-if the primary prefix couldn't be created. This is useful for avoiding failures
-in environments where the primary prefix may or may not be available, but you'd
-like to try. The canonical example is when running `mgmt` with `--remote` there
-might be a cached copy of the binary in the primary prefix, but in case there's
-no binary available continue working in a temporary directory to avoid failure.
-
-##Examples
-For example configurations, please consult the [examples/](https://github.com/purpleidea/mgmt/tree/master/examples) directory in the git
-source repository. It is available from:
-
-[https://github.com/purpleidea/mgmt/tree/master/examples](https://github.com/purpleidea/mgmt/tree/master/examples)
-
-### Systemd:
-See [`misc/mgmt.service`](misc/mgmt.service) for a sample systemd unit file.
-This unit file is part of the RPM.
-
-To specify your custom options for `mgmt` on a systemd distro:
-
-```bash
-sudo mkdir -p /etc/systemd/system/mgmt.service.d/
-
-cat > /etc/systemd/system/mgmt.service.d/env.conf <<EOF
-# Environment variables:
-MGMT_SEEDS=http://127.0.0.1:2379
-MGMT_CONVERGED_TIMEOUT=-1
-MGMT_MAX_RUNTIME=0
-
-# Other CLI options if necessary.
-#OPTS="--max-runtime=0"
-EOF
-
-sudo systemctl daemon-reload
-```
-
-##Development
-
-This is a project that I started in my free time in 2013. Development is driven
-by all of our collective patches! Dive right in, and start hacking!
-Please contact me if you'd like to invite me to speak about this at your event.
-
-You can follow along [on my technical blog](https://ttboj.wordpress.com/).
-
-To report any bugs, please file a ticket at: [https://github.com/purpleidea/mgmt/issues](https://github.com/purpleidea/mgmt/issues).
-
-##Authors
-
-Copyright (C) 2013-2016+ James Shubin and the project contributors
-
-Please see the
-[AUTHORS](https://github.com/purpleidea/mgmt/tree/master/AUTHORS) file
-for more information.
-
-* [github](https://github.com/purpleidea/)
-* [&#64;purpleidea](https://twitter.com/#!/purpleidea)
-* [https://ttboj.wordpress.com/](https://ttboj.wordpress.com/)

Makefile

@@ -1,33 +1,61 @@
 # Mgmt
-# Copyright (C) 2013-2016+ James Shubin and the project contributors
+# Copyright (C) James Shubin and the project contributors
 # Written by James Shubin <james@shubin.ca> and the project contributors
 #
 # This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Affero General Public License as published by
+# it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Affero General Public License for more details.
+# GNU General Public License for more details.
 #
-# You should have received a copy of the GNU Affero General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+#
+# Additional permission under GNU GPL version 3 section 7
+#
+# If you modify this program, or any covered work, by linking or combining it
+# with embedded mcl code and modules (and that the embedded mcl code and
+# modules which link with this program, contain a copy of their source code in
+# the authoritative form) containing parts covered by the terms of any other
+# license, the licensors of this program grant you additional permission to
+# convey the resulting work. Furthermore, the licensors of this program grant
+# the original author, James Shubin, additional permission to update this
+# additional permission if he deems it necessary to achieve the goals of this
+# additional permission.
 
-SHELL = /usr/bin/env bash
-.PHONY: all art cleanart version program path deps run race generate build clean test gofmt yamlfmt format docs rpmbuild mkdirs rpm srpm spec tar upload upload-sources upload-srpms upload-rpms copr
+SHELL = bash
+.PHONY: all art cleanart version program lang path deps run race generate build build-debug crossbuild clean test gofmt yamlfmt format docs
+.PHONY: rpmbuild mkdirs rpm srpm spec tar upload upload-sources upload-srpms upload-rpms upload-releases copr tag
+.PHONY: mkosi mkosi_fedora-latest mkosi_fedora-older mkosi_stream-latest mkosi_debian-stable mkosi_ubuntu-latest mkosi_archlinux
+.PHONY: release release_test releases_path release_binary_amd64 release_binary_arm64 release_fedora-latest release_fedora-older release_stream-latest release_debian-stable release_ubuntu-latest release_archlinux
+.PHONY: funcgen
 .SILENT: clean
 
+# a large amount of output from this `find`, can cause `make` to be much slower!
+GO_FILES := $(shell find * -name '*.go' -not -path 'old/*' -not -path 'tmp/*')
+MCL_FILES := $(shell find lang/ -name '*.mcl' -not -path 'old/*' -not -path 'tmp/*')
+MISC_FILES := $(shell find engine/resources/http_server_ui/)
+
 SVERSION := $(or $(SVERSION),$(shell git describe --match '[0-9]*\.[0-9]*\.[0-9]*' --tags --dirty --always))
 VERSION := $(or $(VERSION),$(shell git describe --match '[0-9]*\.[0-9]*\.[0-9]*' --tags --abbrev=0))
 PROGRAM := $(shell echo $(notdir $(CURDIR)) | cut -f1 -d"-")
-OLDGOLANG := $(shell go version | grep -E 'go1.3|go1.4')
+PKGNAME := $(shell go list .)
 ifeq ($(VERSION),$(SVERSION))
 	RELEASE = 1
 else
 	RELEASE = untagged
 endif
+# debugging is harder if -trimpath is set, so disable it if env var is set
+# this is force enabled automatically when using the release target
+ifeq ($(MGMT_NOTRIMPATH),true)
+	TRIMPATH =
+else
+	TRIMPATH = -trimpath
+endif
 ARCH = $(uname -m)
 SPEC = rpmbuild/SPECS/$(PROGRAM).spec
 SOURCE = rpmbuild/SOURCES/$(PROGRAM)-$(VERSION).tar.bz2
@@ -36,12 +64,87 @@ SRPM_BASE = $(PROGRAM)-$(VERSION)-$(RELEASE).src.rpm
 RPM = rpmbuild/RPMS/$(PROGRAM)-$(VERSION)-$(RELEASE).$(ARCH).rpm
 USERNAME := $(shell cat ~/.config/copr 2>/dev/null | grep username | awk -F '=' '{print $$2}' | tr -d ' ')
 SERVER = 'dl.fedoraproject.org'
-REMOTE_PATH = 'pub/alt/$(USERNAME)/$(PROGRAM)'
+REMOTE_PATH = '/srv/pub/alt/$(USERNAME)/$(PROGRAM)'
+ifneq ($(GOTAGS),)
+	BUILD_FLAGS = -tags '$(GOTAGS)'
+endif
+GOOSARCHES ?= linux/amd64 linux/ppc64 linux/ppc64le linux/arm64 darwin/amd64
+
+GOHOSTOS = $(shell go env GOHOSTOS)
+GOHOSTARCH = $(shell go env GOHOSTARCH)
+
+# The underscores separate the prefix name ("TOKEN") the distro ("BINARY",
+# "FEDORA-LATEST", etc...) and the arch ("AMD64"). The distro can have a dash.
+TOKEN_BINARY_AMD64 = $(shell grep -v '#' releases/binary-amd64.release)
+TOKEN_BINARY_ARM64 = $(shell grep -v '#' releases/binary-arm64.release)
+TOKEN_FEDORA-LATEST = $(shell grep -v '#' releases/fedora-latest.release)
+TOKEN_FEDORA-OLDER = $(shell grep -v '#' releases/fedora-older.release)
+TOKEN_STREAM-LATEST = $(shell grep -v '#' releases/stream-latest.release)
+TOKEN_DEBIAN-STABLE = $(shell grep -v '#' releases/debian-stable.release)
+TOKEN_UBUNTU-LATEST = $(shell grep -v '#' releases/ubuntu-latest.release)
+TOKEN_ARCHLINUX = $(shell grep -v '#' releases/archlinux.release)
+
+FILE_BINARY_AMD64 = mgmt-linux-amd64-$(VERSION)
+FILE_BINARY_ARM64 = mgmt-linux-arm64-$(VERSION)
+# TODO: add ARCH onto these at the end, eg _AMD64
+FILE_FEDORA-LATEST = mgmt-$(TOKEN_FEDORA-LATEST)-$(VERSION)-1.x86_64.rpm
+FILE_FEDORA-OLDER = mgmt-$(TOKEN_FEDORA-OLDER)-$(VERSION)-1.x86_64.rpm
+FILE_STREAM-LATEST = mgmt-$(TOKEN_STREAM-LATEST)-$(VERSION)-1.x86_64.rpm
+FILE_DEBIAN-STABLE = mgmt_$(TOKEN_DEBIAN-STABLE)_$(VERSION)_amd64.deb
+FILE_UBUNTU-LATEST = mgmt_$(TOKEN_UBUNTU-LATEST)_$(VERSION)_amd64.deb
+FILE_ARCHLINUX = mgmt-$(TOKEN_ARCHLINUX)-$(VERSION)-1-x86_64.pkg.tar.xz
+
+PKG_BINARY_AMD64 = releases/$(VERSION)/$(TOKEN_BINARY_AMD64)/$(FILE_BINARY_AMD64)
+PKG_BINARY_ARM64 = releases/$(VERSION)/$(TOKEN_BINARY_ARM64)/$(FILE_BINARY_ARM64)
+PKG_FEDORA-LATEST = releases/$(VERSION)/$(TOKEN_FEDORA-LATEST)/$(FILE_FEDORA-LATEST)
+PKG_FEDORA-OLDER = releases/$(VERSION)/$(TOKEN_FEDORA-OLDER)/$(FILE_FEDORA-OLDER)
+PKG_STREAM-LATEST = releases/$(VERSION)/$(TOKEN_STREAM-LATEST)/$(FILE_STREAM-LATEST)
+PKG_DEBIAN-STABLE = releases/$(VERSION)/$(TOKEN_DEBIAN-STABLE)/$(FILE_DEBIAN-STABLE)
+PKG_UBUNTU-LATEST = releases/$(VERSION)/$(TOKEN_UBUNTU-LATEST)/$(FILE_UBUNTU-LATEST)
+PKG_ARCHLINUX = releases/$(VERSION)/$(TOKEN_ARCHLINUX)/$(FILE_ARCHLINUX)
+
+DEP_BINARY_AMD64 =
+ifneq ($(TOKEN_BINARY_AMD64),)
+	DEP_BINARY_AMD64 = $(PKG_BINARY_AMD64)
+endif
+DEP_BINARY_ARM64 =
+ifneq ($(TOKEN_BINARY_ARM64),)
+	DEP_BINARY_ARM64 = $(PKG_BINARY_ARM64)
+endif
+DEP_FEDORA-LATEST =
+ifneq ($(TOKEN_FEDORA-LATEST),)
+	DEP_FEDORA-LATEST = $(PKG_FEDORA-LATEST)
+endif
+DEP_FEDORA-OLDER =
+ifneq ($(TOKEN_FEDORA-OLDER),)
+	DEP_FEDORA-OLDER = $(PKG_FEDORA-OLDER)
+endif
+DEP_STREAM-LATEST =
+ifneq ($(TOKEN_STREAM-LATEST),)
+	DEP_STREAM-LATEST = $(PKG_STREAM-LATEST)
+endif
+DEP_DEBIAN-STABLE =
+ifneq ($(TOKEN_DEBIAN-STABLE),)
+	DEP_DEBIAN-STABLE = $(PKG_DEBIAN-STABLE)
+endif
+DEP_UBUNTU-LATEST =
+ifneq ($(TOKEN_UBUNTU-LATEST),)
+	DEP_UBUNTU-LATEST = $(PKG_UBUNTU-LATEST)
+endif
+DEP_ARCHLINUX =
+ifneq ($(TOKEN_ARCHLINUX),)
+	DEP_ARCHLINUX = $(PKG_ARCHLINUX)
+endif
+
+SHA256SUMS = releases/$(VERSION)/SHA256SUMS
+SHA256SUMS_ASC = $(SHA256SUMS).asc
+
+default: build
 
 #
 #	art
 #
-art: art/mgmt_logo_default_symbol.png art/mgmt_logo_default_tall.png art/mgmt_logo_default_wide.png art/mgmt_logo_reversed_symbol.png art/mgmt_logo_reversed_tall.png art/mgmt_logo_reversed_wide.png art/mgmt_logo_white_symbol.png art/mgmt_logo_white_tall.png art/mgmt_logo_white_wide.png
+art: art/mgmt_logo_default_symbol.png art/mgmt_logo_default_tall.png art/mgmt_logo_default_wide.png art/mgmt_logo_reversed_symbol.png art/mgmt_logo_reversed_tall.png art/mgmt_logo_reversed_wide.png art/mgmt_logo_white_symbol.png art/mgmt_logo_white_tall.png art/mgmt_logo_white_wide.png ## generate artwork
 
 cleanart:
 	rm -f art/mgmt_logo_default_symbol.png art/mgmt_logo_default_tall.png art/mgmt_logo_default_wide.png art/mgmt_logo_reversed_symbol.png art/mgmt_logo_reversed_tall.png art/mgmt_logo_reversed_wide.png art/mgmt_logo_white_symbol.png art/mgmt_logo_white_tall.png art/mgmt_logo_white_wide.png
@@ -77,69 +180,111 @@ art/mgmt_logo_white_wide.png: art/mgmt_logo_white_wide.svg
 all: docs $(PROGRAM).static
 
 # show the current version
-version:
+version: ## show the current version
 	@echo $(VERSION)
 
-program:
+program: ## show the program name
 	@echo $(PROGRAM)
 
-path:
+path: ## create working paths
 	./misc/make-path.sh
 
-deps:
+deps: ## install system and golang dependencies
 	./misc/make-deps.sh
 
-run:
-	find . -maxdepth 1 -type f -name '*.go' -not -name '*_test.go' | xargs go run -ldflags "-X main.program=$(PROGRAM) -X main.version=$(SVERSION)"
-
-# include race flag
-race:
-	find . -maxdepth 1 -type f -name '*.go' -not -name '*_test.go' | xargs go run -race -ldflags "-X main.program=$(PROGRAM) -X main.version=$(SVERSION)"
-
 generate:
 	go generate
 
-build: $(PROGRAM)
+lang: ## generates the lexer/parser for the language frontend
+	@# recursively run make in child dir named lang
+	@$(MAKE) --quiet -C lang
 
-$(PROGRAM): main.go
-	@echo "Building: $(PROGRAM), version: $(SVERSION)..."
-ifneq ($(OLDGOLANG),)
-	@# avoid equals sign in old golang versions eg in: -X foo=bar
-	time go build -ldflags "-X main.program $(PROGRAM) -X main.version $(SVERSION)" -o $(PROGRAM);
-else
-	time go build -ldflags "-X main.program=$(PROGRAM) -X main.version=$(SVERSION)" -o $(PROGRAM);
-endif
+resources: ## builds the resources dependencies required for the engine backend
+	@# recursively run make in child dir named engine/resources
+	@$(MAKE) --quiet -C engine/resources
 
-$(PROGRAM).static: main.go
+# build a `mgmt` binary for current host os/arch
+$(PROGRAM): build/mgmt-${GOHOSTOS}-${GOHOSTARCH} ## build an mgmt binary for current host os/arch
+	cp -a $< $@
+
+$(PROGRAM).static: $(GO_FILES) $(MCL_FILES) $(MISC_FILES) go.mod go.sum
 	@echo "Building: $(PROGRAM).static, version: $(SVERSION)..."
 	go generate
-ifneq ($(OLDGOLANG),)
-	@# avoid equals sign in old golang versions eg in: -X foo=bar
-	go build -a -installsuffix cgo -tags netgo -ldflags '-extldflags "-static" -X main.program $(PROGRAM) -X main.version $(SVERSION)' -o $(PROGRAM).static;
-else
-	go build -a -installsuffix cgo -tags netgo -ldflags '-extldflags "-static" -X main.program=$(PROGRAM) -X main.version=$(SVERSION)' -o $(PROGRAM).static;
-endif
+	go build $(TRIMPATH) -a -installsuffix cgo -tags netgo -ldflags '-extldflags "-static" -X main.program=$(PROGRAM) -X main.version=$(SVERSION) -s -w' -o $(PROGRAM).static $(BUILD_FLAGS);
 
-clean:
+build: LDFLAGS=-s -w ## build a fresh mgmt binary
+build: $(PROGRAM)
+
+build-debug: LDFLAGS=
+build-debug: $(PROGRAM)
+
+# if you're using the bad/dev branch, you might want this too!
+baddev: BUILD_FLAGS = -tags 'noaugeas novirt'
+baddev: $(PROGRAM)
+
+# pattern rule target for (cross)building, mgmt-OS-ARCH will be expanded to the correct build
+# extract os and arch from target pattern
+GOOS=$(firstword $(subst -, ,$*))
+GOARCH=$(lastword $(subst -, ,$*))
+build/mgmt-%: $(GO_FILES) $(MCL_FILES) $(MISC_FILES) go.mod go.sum | lang resources funcgen
+	@# If you need to run `go mod tidy` then this can trigger.
+	@if [ "$(PKGNAME)" = "" ]; then echo "\$$(PKGNAME) is empty, test with: go list ."; exit 42; fi
+	@echo "Building: $(PROGRAM), os/arch: $*, version: $(SVERSION)..."
+	@# XXX: leave race detector on by default for now. For production
+	@# builds, we can consider turning it off for performance improvements.
+	@# XXX: ./mgmt run --tmp-prefix lang something_fast.mcl > /tmp/race 2>&1 # search for "WARNING: DATA RACE"
+	time env GOOS=${GOOS} GOARCH=${GOARCH} go build $(TRIMPATH) -race -ldflags=$(PKGNAME)="-X main.program=$(PROGRAM) -X main.version=$(SVERSION) ${LDFLAGS}" -o $@ $(BUILD_FLAGS)
+
+# create a list of binary file names to use as make targets
+# to use this you might want to run something like:
+# GOOSARCHES='linux/arm64' GOTAGS='noaugeas novirt' make crossbuild
+# and the output will end up in build/
+crossbuild_targets = $(addprefix build/mgmt-,$(subst /,-,${GOOSARCHES}))
+crossbuild: ${crossbuild_targets}
+
+clean: ## clean things up
+	$(MAKE) --quiet -C test clean
+	$(MAKE) --quiet -C lang clean
+	$(MAKE) --quiet -C engine/resources clean
+	$(MAKE) --quiet -C misc/mkosi clean
+	rm -f lang/core/generated_funcs.go || true
+	rm -f lang/core/generated_funcs_test.go || true
 	[ ! -e $(PROGRAM) ] || rm $(PROGRAM)
 	rm -f *_stringer.go	# generated by `go generate`
 	rm -f *_mock.go		# generated by `go generate`
+	# crossbuild artifacts
+	rm -f build/mgmt-*
 
-test:
+test: build ## run tests
+	@# recursively run make in child dir named test
+	@$(MAKE) --quiet -C test
 	./test.sh
 
+# create all test targets for make tab completion (eg: make test-gofmt)
+test_suites=$(shell find test/ -maxdepth 1 -name test-* -exec basename {} .sh \;)
+# allow to run only one test suite at a time
+${test_suites}: test-%: build
+	./test.sh $*
+
+# targets to run individual shell tests (eg: make test-shell-load0)
+test_shell=$(shell find test/shell/ -maxdepth 1 -name "*.sh" -exec basename {} .sh \;)
+$(addprefix test-shell-,${test_shell}): test-shell-%: build
+	./test/test-shell.sh "$*.sh"
+
 gofmt:
-	find . -maxdepth 3 -type f -name '*.go' -not -path './old/*' -not -path './tmp/*' -exec gofmt -w {} \;
+	# TODO: remove gofmt once goimports has a -s option
+	find . -maxdepth 9 -type f -name '*.go' -not -path './old/*' -not -path './tmp/*' -not -path './vendor/*' -exec gofmt -s -w {} \;
+	find . -maxdepth 9 -type f -name '*.go' -not -path './old/*' -not -path './tmp/*' -not -path './vendor/*' -exec goimports -w {} \;
 
 yamlfmt:
 	find . -maxdepth 3 -type f -name '*.yaml' -not -path './old/*' -not -path './tmp/*' -not -path './omv.yaml' -exec ruby -e "require 'yaml'; x=YAML.load_file('{}').to_yaml.each_line.map(&:rstrip).join(10.chr)+10.chr; File.open('{}', 'w').write x" \;
 
-format: gofmt yamlfmt
+format: gofmt yamlfmt ## format yaml and golang code
 
-docs: $(PROGRAM)-documentation.pdf
+docs: $(PROGRAM)-documentation.pdf ## generate docs
 
-$(PROGRAM)-documentation.pdf: DOCUMENTATION.md
-	pandoc DOCUMENTATION.md -o '$(PROGRAM)-documentation.pdf'
+$(PROGRAM)-documentation.pdf: docs/documentation.md
+	pandoc docs/documentation.md -o docs/'$(PROGRAM)-documentation.pdf'
 
 #
 #	build aliases
@@ -161,7 +306,7 @@ rpmbuild/SOURCES/: tar
 rpmbuild/SRPMS/: srpm
 rpmbuild/RPMS/: rpm
 
-upload: upload-sources upload-srpms upload-rpms
+upload: upload-sources upload-srpms upload-rpms ## upload sources
 	# do nothing
 
 #
@@ -183,7 +328,7 @@ $(SRPM): $(SPEC) $(SOURCE)
 #
 $(SPEC): rpmbuild/ spec.in
 	@echo Running templater...
-	#cat spec.in > $(SPEC)
+	cat spec.in > $(SPEC)
 	sed -e s/__PROGRAM__/$(PROGRAM)/g -e s/__VERSION__/$(VERSION)/g -e s/__RELEASE__/$(RELEASE)/g < spec.in > $(SPEC)
 	# append a changelog to the .spec file
 	git log --format="* %cd %aN <%aE>%n- (%h) %s%d%n" --date=local | sed -r 's/[0-9]+:[0-9]+:[0-9]+ //' >> $(SPEC)
@@ -266,10 +411,244 @@ upload-rpms: rpmbuild/RPMS/ rpmbuild/RPMS/SHA256SUMS rpmbuild/RPMS/SHA256SUMS.as
 		rsync -avz --prune-empty-dirs rpmbuild/RPMS/ $(SERVER):$(REMOTE_PATH)/RPMS/; \
 	fi
 
+upload-releases:
+	echo Running releases/ upload...
+	rsync -avz --exclude '.mkdir' --exclude 'mgmt-release.url' releases/ $(SERVER):$(REMOTE_PATH)/releases/
+
 #
 #	copr build
 #
-copr: upload-srpms
+copr: upload-srpms ## build in copr
 	./misc/copr-build.py https://$(SERVER)/$(REMOTE_PATH)/SRPMS/$(SRPM_BASE)
 
+#
+#	tag
+#
+tag: ## tags a new release
+	./misc/tag.sh
+
+#
+#	mkosi
+#
+mkosi: mkosi_fedora-latest mkosi_fedora-older mkosi_stream-latest mkosi_debian-stable mkosi_ubuntu-latest mkosi_archlinux ## builds distro packages via mkosi
+
+mkosi_fedora-latest: releases/$(VERSION)/.mkdir
+	@title='$@' ; echo "Generating: $${title#'mkosi_'} via mkosi..."
+	@title='$@' ; distro=$${title#'mkosi_'} ; ./misc/mkosi/make.sh $${distro} `realpath "releases/$(VERSION)/"`
+
+mkosi_fedora-older: releases/$(VERSION)/.mkdir
+	@title='$@' ; echo "Generating: $${title#'mkosi_'} via mkosi..."
+	@title='$@' ; distro=$${title#'mkosi_'} ; ./misc/mkosi/make.sh $${distro} `realpath "releases/$(VERSION)/"`
+
+mkosi_stream-latest: releases/$(VERSION)/.mkdir
+	@title='$@' ; echo "Generating: $${title#'mkosi_'} via mkosi..."
+	@title='$@' ; distro=$${title#'mkosi_'} ; ./misc/mkosi/make.sh $${distro} `realpath "releases/$(VERSION)/"`
+
+mkosi_debian-stable: releases/$(VERSION)/.mkdir
+	@title='$@' ; echo "Generating: $${title#'mkosi_'} via mkosi..."
+	@title='$@' ; distro=$${title#'mkosi_'} ; ./misc/mkosi/make.sh $${distro} `realpath "releases/$(VERSION)/"`
+
+mkosi_ubuntu-latest: releases/$(VERSION)/.mkdir
+	@title='$@' ; echo "Generating: $${title#'mkosi_'} via mkosi..."
+	@title='$@' ; distro=$${title#'mkosi_'} ; ./misc/mkosi/make.sh $${distro} `realpath "releases/$(VERSION)/"`
+
+mkosi_archlinux: releases/$(VERSION)/.mkdir
+	@title='$@' ; echo "Generating: $${title#'mkosi_'} via mkosi..."
+	@title='$@' ; distro=$${title#'mkosi_'} ; ./misc/mkosi/make.sh $${distro} `realpath "releases/$(VERSION)/"`
+
+#
+#	release
+#
+release: TRIMPATH = -trimpath
+release: releases/$(VERSION)/mgmt-release.url ## generates and uploads a release
+
+releases_path:
+	@#Don't put any other output or dependencies in here or they'll show!
+	@echo "releases/$(VERSION)/"
+
+release_test: $(DEP_BINARY_AMD64) $(DEP_BINARY_ARM64) $(DEP_FEDORA-LATEST) $(DEP_FEDORA-OLDER) $(DEP_STREAM-LATEST) $(DEP_DEBIAN-STABLE) $(DEP_UBUNTU-LATEST) $(DEP_ARCHLINUX) $(SHA256SUMS_ASC)
+	@echo '$$< denotes ‘the first dependency of the current rule’.'
+	@echo '> '"$<"
+	@echo
+	@echo '$$@ denotes ‘the target of the current rule’.'
+	@echo '> '"$@"
+	@echo
+	@echo '$$^ denotes ‘the dependencies of the current rule’.'
+	@echo '> '"$^"
+	@echo
+	@echo '$$* denotes ‘the stem with which the pattern of the current rule matched’.'
+	@echo '> '"$*"
+	@echo
+	@echo "TOKEN_BINARY_AMD64: $(TOKEN_BINARY_AMD64)"
+	@echo "DEP_BINARY_AMD64: $(DEP_BINARY_AMD64)"
+	@echo
+	@echo "TOKEN_BINARY_ARM64: $(TOKEN_BINARY_ARM64)"
+	@echo "DEP_BINARY_ARM64: $(DEP_BINARY_ARM64)"
+	@echo
+	@echo "TOKEN_FEDORA-LATEST: $(TOKEN_FEDORA-LATEST)"
+	@echo "DEP_FEDORA-LATEST: $(DEP_FEDORA-LATEST)"
+	@echo
+	@echo "TOKEN_FEDORA-OLDER: $(TOKEN_FEDORA-OLDER)"
+	@echo "DEP_FEDORA-OLDER: $(DEP_FEDORA-OLDER)"
+	@echo
+	@echo "TOKEN_STREAM-LATEST: $(TOKEN_STREAM-LATEST)"
+	@echo "DEP_STREAM-LATEST: $(DEP_STREAM-LATEST)"
+	@echo
+	@echo "TOKEN_DEBIAN-STABLE: $(TOKEN_DEBIAN-STABLE)"
+	@echo "DEP_DEBIAN-STABLE: $(DEP_DEBIAN-STABLE)"
+	@echo
+	@echo "TOKEN_UBUNTU-LATEST: $(TOKEN_UBUNTU-LATEST)"
+	@echo "DEP_UBUNTU-LATEST: $(DEP_UBUNTU-LATEST)"
+	@echo
+	@echo "TOKEN_ARCHLINUX: $(TOKEN_ARCHLINUX)"
+	@echo "DEP_ARCHLINUX: $(DEP_ARCHLINUX)"
+
+release_binary_amd64: $(PKG_BINARY_AMD64)
+release_binary_arm64: $(PKG_BINARY_ARM64)
+release_fedora-latest: $(PKG_FEDORA-LATEST)
+release_fedora-older: $(PKG_FEDORA-OLDER)
+release_stream-latest: $(PKG_STREAM-LATEST)
+release_debian-stable: $(PKG_DEBIAN-STABLE)
+release_ubuntu-latest: $(PKG_UBUNTU-LATEST)
+release_archlinux: $(PKG_ARCHLINUX)
+
+releases/$(VERSION)/mgmt-release.url: $(DEP_BINARY_AMD64) $(DEP_BINARY_ARM64) $(DEP_FEDORA-LATEST) $(DEP_FEDORA-OLDER) $(DEP_STREAM-LATEST) $(DEP_DEBIAN-STABLE) $(DEP_UBUNTU-LATEST) $(DEP_ARCHLINUX) $(SHA256SUMS_ASC)
+	@echo "Pushing git tag $(VERSION) to origin..."
+	git push origin $(VERSION)
+	@echo "Creating github release..."
+	hub release create \
+		-F <( echo -e "$(VERSION)\n";echo "Verify the signatures of all packages before you use them. The signing key can be downloaded from https://purpleidea.com/contact/#pgp-key to verify the release." ) \
+		` [ -e $(PKG_BINARY_AMD64) ] && printf -- "-a $(PKG_BINARY_AMD64)" ` \
+		` [ -e $(PKG_BINARY_ARM64) ] && printf -- "-a $(PKG_BINARY_ARM64)" ` \
+		` [ -e $(PKG_FEDORA-LATEST) ] && printf -- "-a $(PKG_FEDORA-LATEST)" ` \
+		` [ -e $(PKG_FEDORA-OLDER) ] && printf -- "-a $(PKG_FEDORA-OLDER)" ` \
+		` [ -e $(PKG_STREAM-LATEST) ] && printf -- "-a $(PKG_STREAM-LATEST)" ` \
+		` [ -e $(PKG_DEBIAN-STABLE) ] && printf -- "-a $(PKG_DEBIAN-STABLE)" ` \
+		` [ -e $(PKG_UBUNTU-LATEST) ] && printf -- "-a $(PKG_UBUNTU-LATEST)" ` \
+		` [ -e $(PKG_ARCHLINUX) ] && printf -- "-a $(PKG_ARCHLINUX)" ` \
+		-a $(SHA256SUMS_ASC) \
+		$(VERSION) \
+		> releases/$(VERSION)/mgmt-release.url \
+		&& cat releases/$(VERSION)/mgmt-release.url \
+		|| rm -f releases/$(VERSION)/mgmt-release.url
+
+releases/$(VERSION)/.mkdir:
+	mkdir -p \
+	` [ "$(TOKEN_BINARY_AMD64)" != "" ] && printf -- "releases/$(VERSION)/$(TOKEN_BINARY_AMD64)/" ` \
+	` [ "$(TOKEN_BINARY_ARM64)" != "" ] && printf -- "releases/$(VERSION)/$(TOKEN_BINARY_ARM64)/" ` \
+	` [ "$(TOKEN_FEDORA-LATEST)" != "" ] && printf -- "releases/$(VERSION)/$(TOKEN_FEDORA-LATEST)/" ` \
+	` [ "$(TOKEN_FEDORA-OLDER)" != "" ] && printf -- "releases/$(VERSION)/$(TOKEN_FEDORA-OLDER)/" ` \
+	` [ "$(TOKEN_STREAM-LATEST)" != "" ] && printf -- "releases/$(VERSION)/$(TOKEN_STREAM-LATEST)/" ` \
+	` [ "$(TOKEN_DEBIAN-STABLE)" != "" ] && printf -- "releases/$(VERSION)/$(TOKEN_DEBIAN-STABLE)/" ` \
+	` [ "$(TOKEN_UBUNTU-LATEST)" != "" ] && printf -- "releases/$(VERSION)/$(TOKEN_UBUNTU-LATEST)/" ` \
+	` [ "$(TOKEN_ARCHLINUX)" != "" ] && printf -- "releases/$(VERSION)/$(TOKEN_ARCHLINUX)/" ` \
+	&& touch releases/$(VERSION)/.mkdir
+
+# These are defined conditionally, since if the token is empty, they warn!
+ifneq ($(TOKEN_BINARY_AMD64),)
+$(PKG_BINARY_AMD64): build/mgmt-linux-amd64 releases/$(VERSION)/.mkdir
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; echo "Building: $${distro} package..."
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; cp -a build/mgmt-linux-amd64 $(PKG_BINARY_AMD64)
+endif
+ifneq ($(TOKEN_BINARY_ARM64),)
+$(PKG_BINARY_ARM64): build/mgmt-linux-arm64 releases/$(VERSION)/.mkdir
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; echo "Building: $${distro} package..."
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; cp -a build/mgmt-linux-arm64 $(PKG_BINARY_ARM64)
+endif
+ifneq ($(TOKEN_FEDORA-LATEST),)
+releases/$(VERSION)/$(TOKEN_FEDORA-LATEST)/changelog: $(PROGRAM) releases/$(VERSION)/.mkdir
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; echo "Generating: $${distro} changelog..."
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; ./misc/make-rpm-changelog.sh "$${distro}" $(VERSION)
+
+$(PKG_FEDORA-LATEST): releases/$(VERSION)/$(TOKEN_FEDORA-LATEST)/changelog
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; echo "Building: $${distro} package..."
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; ./misc/fpm-pack.sh $${distro} $(VERSION) "$(FILE_FEDORA-LATEST)" libvirt-devel augeas-devel
+endif
+ifneq ($(TOKEN_FEDORA-OLDER),)
+releases/$(VERSION)/$(TOKEN_FEDORA-OLDER)/changelog: $(PROGRAM) releases/$(VERSION)/.mkdir
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; echo "Generating: $${distro} changelog..."
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; ./misc/make-rpm-changelog.sh "$${distro}" $(VERSION)
+
+$(PKG_FEDORA-OLDER): releases/$(VERSION)/$(TOKEN_FEDORA-OLDER)/changelog
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; echo "Building: $${distro} package..."
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; ./misc/fpm-pack.sh $${distro} $(VERSION) "$(FILE_FEDORA-OLDER)" libvirt-devel augeas-devel
+endif
+ifneq ($(TOKEN_STREAM-LATEST),)
+releases/$(VERSION)/$(TOKEN_STREAM-LATEST)/changelog: $(PROGRAM) releases/$(VERSION)/.mkdir
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; echo "Generating: $${distro} changelog..."
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; ./misc/make-rpm-changelog.sh "$${distro}" $(VERSION)
+
+$(PKG_STREAM-LATEST): releases/$(VERSION)/$(TOKEN_STREAM-LATEST)/changelog
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; echo "Building: $${distro} package..."
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; ./misc/fpm-pack.sh $${distro} $(VERSION) "$(FILE_STREAM-LATEST)" libvirt-devel augeas-devel
+endif
+ifneq ($(TOKEN_DEBIAN-STABLE),)
+releases/$(VERSION)/$(TOKEN_DEBIAN-STABLE)/changelog: $(PROGRAM) releases/$(VERSION)/.mkdir
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; echo "Generating: $${distro} changelog..."
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; ./misc/make-deb-changelog.sh "$${distro}" $(VERSION)
+
+$(PKG_DEBIAN-STABLE): releases/$(VERSION)/$(TOKEN_DEBIAN-STABLE)/changelog
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; echo "Building: $${distro} package..."
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; ./misc/fpm-pack.sh $${distro} $(VERSION) "$(FILE_DEBIAN-STABLE)" libvirt-dev libaugeas-dev
+endif
+ifneq ($(TOKEN_UBUNTU-LATEST),)
+releases/$(VERSION)/$(TOKEN_UBUNTU-LATEST)/changelog: $(PROGRAM) releases/$(VERSION)/.mkdir
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; echo "Generating: $${distro} changelog..."
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; ./misc/make-deb-changelog.sh "$${distro}" $(VERSION)
+
+$(PKG_UBUNTU-LATEST): releases/$(VERSION)/$(TOKEN_UBUNTU-LATEST)/changelog
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; echo "Building: $${distro} package..."
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; ./misc/fpm-pack.sh $${distro} $(VERSION) "$(FILE_UBUNTU-LATEST)" libvirt-dev libaugeas-dev
+endif
+ifneq ($(TOKEN_ARCHLINUX),)
+$(PKG_ARCHLINUX): $(PROGRAM) releases/$(VERSION)/.mkdir
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; echo "Building: $${distro} package..."
+	@title='$(@D)' ; distro=$${title#'releases/$(VERSION)/'} ; ./misc/fpm-pack.sh $${distro} $(VERSION) "$(FILE_ARCHLINUX)" libvirt augeas
+endif
+
+$(SHA256SUMS): $(DEP_BINARY_AMD64) $(DEP_BINARY_ARM64) $(DEP_FEDORA-LATEST) $(DEP_FEDORA-OLDER) $(DEP_STREAM-LATEST) $(DEP_DEBIAN-STABLE) $(DEP_UBUNTU-LATEST) $(DEP_ARCHLINUX)
+	@# remove the directory separator in the SHA256SUMS file
+	@echo "Generating: sha256 sum..."
+	sha256sum \
+	` [ -e $(PKG_BINARY_AMD64) ] && printf -- "$(PKG_BINARY_AMD64)" ` \
+	` [ -e $(PKG_BINARY_ARM64) ] && printf -- "$(PKG_BINARY_ARM64)" ` \
+	` [ -e $(PKG_FEDORA-LATEST) ] && printf -- "$(PKG_FEDORA-LATEST)" ` \
+	` [ -e $(PKG_FEDORA-OLDER) ] && printf -- "$(PKG_FEDORA-OLDER)" ` \
+	` [ -e $(PKG_STREAM-LATEST) ] && printf -- "$(PKG_STREAM-LATEST)" ` \
+	` [ -e $(PKG_DEBIAN-STABLE) ] && printf -- "$(PKG_DEBIAN-STABLE)" ` \
+	` [ -e $(PKG_UBUNTU-LATEST) ] && printf -- "$(PKG_UBUNTU-LATEST)" ` \
+	` [ -e $(PKG_ARCHLINUX) ] && printf -- "$(PKG_ARCHLINUX)" ` \
+	| awk -F '/| ' '{print $$1"  "$$6}' > $(SHA256SUMS)
+
+$(SHA256SUMS_ASC): $(SHA256SUMS)
+	@echo "Signing sha256 sum..."
+	gpg2 --yes --clearsign $(SHA256SUMS)
+
+build_container: ## builds the container
+	docker build -t purpleidea/mgmt-build -f docker/Dockerfile.build .
+	docker run -td --name mgmt-build purpleidea/mgmt-build
+	docker cp mgmt-build:/root/gopath/src/github.com/purpleidea/mgmt/mgmt .
+	docker build -t purpleidea/mgmt -f docker/Dockerfile.static .
+	docker rm mgmt-build || true
+
+clean_container: ## removes the container
+	docker rmi purpleidea/mgmt-build
+	docker rmi purpleidea/mgmt
+
+help: ## show this help screen
+	@echo 'Usage: make <OPTIONS> ... <TARGETS>'
+	@echo ''
+	@echo 'Available targets are:'
+	@echo ''
+	@grep -E '^[ a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | \
+		awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-20s\033[0m %s\n", $$1, $$2}'
+	@echo ''
+
+funcgen: lang/core/generated_funcs.go
+
+lang/core/generated_funcs.go: lang/funcs/funcgen/*.go lang/core/funcgen.yaml lang/funcs/funcgen/templates/generated_funcs.go.tpl
+	@echo "Generating: funcs..."
+	@go run `find lang/funcs/funcgen/ -maxdepth 1 -type f -name '*.go' -not -name '*_test.go'` -templates=lang/funcs/funcgen/templates/generated_funcs.go.tpl >/dev/null
+	@gofmt -s -w $@
+
 # vim: ts=8

Puppet.md

@@ -1,163 +0,0 @@
-#mgmt Puppet support
-
-1. [Prerequisites](#prerequisites)
-    * [Testing the Puppet side](#testing-the-puppet-side)
-2. [Writing a suitable manifest](#writing-a-suitable-manifest)
-    * [Unsupported attributes](#unsupported-attributes)
-    * [Unsupported resources](#unsupported-resources)
-    * [Avoiding common warnings](#avoiding-common-warnings)
-3. [Configuring Puppet](#configuring-puppet)
-4. [Caveats](#caveats)
-
-`mgmt` can use Puppet as its source for the configuration graph.
-This document goes into detail on how this works, and lists
-some pitfalls and limitations.
-
-For basic instructions on how to use the Puppet support, see
-the [main documentation](DOCUMENTATION.md#puppet-support).
-
-##Prerequisites
-
-You need Puppet installed in your system. It is not important how you
-get it. On the most common Linux distributions, you can use packages
-from the OS maintainer, or upstream Puppet repositories. An alternative
-that will also work on OSX is the `puppet` Ruby gem. It also has the
-advantage that you can install any desired version in your home directory
-or any other location.
-
-Any release of Puppet's 3.x and 4.x series should be suitable for use with
-`mgmt`. Most importantly, make sure to install the `ffrank-mgmtgraph` Puppet
-module (referred to below as "the translator module").
-
-    puppet module install ffrank-mgmtgraph
-
-Please note that the module is not required on your Puppet master (if you
-use a master/agent setup). It's needed on the machine that runs `mgmt`.
-You can install the module on the master anyway, so that it gets distributed
-to your agents through Puppet's `pluginsync` mechanism.
-
-###Testing the Puppet side
-
-The following command should run successfully and print a YAML hash on your
-terminal:
-
-```puppet
-puppet mgmtgraph print --code 'file { "/tmp/mgmt-test": ensure => present }'
-```
-
-You can use this CLI to test any manifests before handing them straight
-to `mgmt`.
-
-##Writing a suitable manifest
-
-###Unsupported attributes
-
-`mgmt` inherited its resource module from Puppet, so by and large, it's quite
-possible to express `mgmt` graphs in terms of Puppet manifests. However,
-there isn't (and likely never will be) full feature parity between the
-respective resource types. In consequence, a manifest can have semantics that
-cannot be transferred to `mgmt`.
-
-For example, at the time of writing this, the `file` type in `mgmt` had no
-notion of permissions (the file `mode`) yet. This lead to the following
-warning (among others that will be discussed below):
-
-    $ puppet mgmtgraph print --code 'file { "/tmp/foo": mode => "0600" }'
-    Warning: cannot translate: File[/tmp/foo] { mode => "600" } (attribute is ignored)
-
-This is a heads-up for the user, because the resulting `mgmt` graph will
-in fact not pass this information to the `/tmp/foo` file resource, and
-`mgmt` will ignore this file's permissions. Including such attributes in
-manifests that are written expressly for `mgmt` is not sensible and should
-be avoided.
-
-###Unsupported resources
-
-Puppet has a fairly large number of
-[built-in types](https://docs.puppet.com/puppet/latest/reference/type.html),
-and countless more are available through
-[modules](https://forge.puppet.com/). It's unlikely that all of them will
-eventually receive native counterparts in `mgmt`.
-
-When encountering an unknown resource, the translator module will replace
-it with an `exec` resource in its output. This resource will run the equivalent
-of a `puppet resource` command to make Puppet apply the original resource
-itself. This has quite abysmal performance, because processing such a
-resource requires the forking of at least one Puppet process (two if it
-is found to be out of sync). This comes with considerable overhead.
-On most systems, starting up any Puppet command takes several seconds.
-Compared to the split second that the actual work usually takes,
-this overhead can amount to several orders of magnitude.
-
-Avoid Puppet types that `mgmt` does not implement (yet).
-
-###Avoiding common warnings
-
-Many resource parameters in Puppet take default values. For the most part,
-the translator module just ignores them. However, there are cases in which
-Puppet will default to convenient behavior that `mgmt` cannot quite replicate.
-For example, translating a plain `file` resource will lead to a warning message:
-
-    $ puppet mgmtgraph print --code 'file { "/tmp/mgmt-test": }'
-    Warning: File[/tmp/mgmt-test] uses the 'puppet' file bucket, which mgmt cannot do. There will be no backup copies!
-
-The reason is that per default, Puppet assumes the following parameter value
-(among others)
-
-```puppet
-file { "/tmp/mgmt-test":
-  backup => 'puppet',
-}
-```
-
-To avoid this, specify the parameter explicitly:
-
-    $ puppet mgmtgraph print --code 'file { "/tmp/mgmt-test": backup => false }'
-
-This is tedious in a more complex manifest. A good simplification is the
-following [resource default](https://docs.puppet.com/puppet/latest/reference/lang_defaults.html)
-anywhere on the top scope of your manifest:
-
-```puppet
-File { backup => false }
-```
-
-If you encounter similar warnings from other types and/or parameters,
-use the same approach to silence them if possible.
-
-##Configuring Puppet
-
-Since `mgmt` uses an actual Puppet CLI behind the scenes, you might
-need to tweak some of Puppet's runtime options in order to make it
-do what you want. Reasons for this could be among the following:
-
-* You use the `--puppet agent` variant and need to configure
-`servername`, `certname` and other master/agent-related options.
-* You don't want runtime information to end up in the `vardir`
-that is used by your regular `puppet agent`.
-* You install specific Puppet modules for `mgmt` in a non-standard
-location.
-
-`mgmt` exposes only one Puppet option in order to allow you to
-control all of them, through its `--puppet-conf` option. It allows
-you to specify which `puppet.conf` file should be used during
-translation.
-
-    mgmt run --puppet /opt/my-manifest.pp --puppet-conf /etc/mgmt/puppet.conf
-
-Within this file, you can just specify any needed options in the
-`[main]` section:
-
-    [main]
-    server=mgmt-master.example.net
-    vardir=/var/lib/mgmt/puppet
-
-##Caveats
-
-Please see the [README](https://github.com/ffrank/puppet-mgmtgraph/blob/master/README.md)
-of the translator module for the current state of supported and unsupported
-language features.
-
-You should probably make sure to always use the latest release of
-both `ffrank-mgmtgraph` and `ffrank-yamlresource` (the latter is
-getting pulled in as a dependency of the former).

README.md

@@ -2,112 +2,152 @@
 
 [![mgmt!](art/mgmt.png)](art/)
 
-[![Go Report Card](https://goreportcard.com/badge/github.com/purpleidea/mgmt)](https://goreportcard.com/report/github.com/purpleidea/mgmt)
-[![Build Status](https://secure.travis-ci.org/purpleidea/mgmt.png?branch=master)](http://travis-ci.org/purpleidea/mgmt)
-[![Documentation](https://img.shields.io/docs/markdown.png)](DOCUMENTATION.md)
-[![GoDoc](https://godoc.org/github.com/purpleidea/mgmt?status.svg)](https://godoc.org/github.com/purpleidea/mgmt)
-[![IRC](https://img.shields.io/irc/%23mgmtconfig.png)](https://webchat.freenode.net/?channels=#mgmtconfig)
-[![Jenkins](https://img.shields.io/jenkins/status.png)](https://ci.centos.org/job/purpleidea-mgmt/)
-[![COPR](https://img.shields.io/copr/builds.png)](https://copr.fedoraproject.org/coprs/purpleidea/mgmt/)
-[![arch](https://img.shields.io/arch/aur.png)](https://aur.archlinux.org/packages/mgmt/)
+[![Go Report Card](https://goreportcard.com/badge/github.com/purpleidea/mgmt?style=flat-square)](https://goreportcard.com/report/github.com/purpleidea/mgmt)
+[![Build Status](https://github.com/purpleidea/mgmt/workflows/.github/workflows/test.yaml/badge.svg)](https://github.com/purpleidea/mgmt/actions/)
+[![GoDoc](https://img.shields.io/badge/godoc-reference-5272B4.svg?style=flat-square)](https://godocs.io/github.com/purpleidea/mgmt)
+[![Matrix](https://img.shields.io/badge/matrix-%23mgmtconfig-orange.svg?style=flat-square)](https://matrix.to/#/#mgmtconfig:matrix.org)
+[![Patreon](https://img.shields.io/badge/patreon-donate-yellow.svg?style=flat-square)](https://www.patreon.com/purpleidea)
+[![Liberapay](https://img.shields.io/badge/liberapay-donate-yellow.svg?style=flat-square)](https://liberapay.com/purpleidea/donate)
+
+> [!TIP]
+> [Resource reference guide now available!](https://mgmtconfig.com/docs/resources/)
+
+> [!TIP]
+> [Function reference guide now available!](https://mgmtconfig.com/docs/functions/)
+
+## About:
+
+`Mgmt` is a real-time automation tool. It is familiar to existing configuration
+management software, but is drastically more powerful as it can allow you to
+build real-time, closed-loop feedback systems, in a very safe way, and with a
+surprisingly small amount of our `mcl` code. For example, the following code
+will ensure that your file server is set to read-only when it's friday.
+
+```mcl
+import "datetime"
+$is_friday = datetime.weekday(datetime.now()) == "friday"
+file "/srv/files/" {
+	state => $const.res.file.state.exists,
+	mode => if $is_friday { # this updates the mode, the instant it changes!
+		"0550"
+	} else {
+		"0770"
+	},
+}
+```
+
+It can run continuously, intermittently, or on-demand, and in the first case, it
+will guarantee that your system is always in the desired state for that instant!
+In this mode it can run as a decentralized cluster of agents across your
+network, each exchanging information with the others in real-time, to respond to
+your changing needs. For example, if you want to ensure that some resource runs
+on a maximum of two hosts in your cluster, you can specify that as well:
+
+```mcl
+import "sys"
+import "world"
+
+# we'll set a few scheduling options:
+$opts = struct{strategy => "rr", max => 2, ttl => 10,}
+
+# schedule in a particular namespace with options:
+$set = world.schedule("xsched", $opts)
+
+if sys.hostname() in $set {
+	# use your imagination to put something more complex right here...
+	print "i got scheduled" {} # this will run on the chosen machines
+}
+```
+
+As you add and remove hosts from the cluster, the real-time `schedule` function
+will dynamically pick up to two hosts from the available pool. These specific
+functions aren't intrinsic to the core design, and new ones can be easily added.
+
+Please read on if you'd like to learn more...
 
 ## Community:
-Come join us on IRC in [#mgmtconfig](https://webchat.freenode.net/?channels=#mgmtconfig) on Freenode!
-You may like the [#mgmtconfig](https://twitter.com/hashtag/mgmtconfig) hashtag if you're on [Twitter](https://twitter.com/#!/purpleidea).
+
+Come join us in the `mgmt` community!
+
+| Medium | Link |
+|---|---|
+| Matrix | [#mgmtconfig](https://matrix.to/#/#mgmtconfig:matrix.org) on Matrix.org |
+| Twitter | [@mgmtconfig](https://twitter.com/mgmtconfig) & [#mgmtconfig](https://twitter.com/hashtag/mgmtconfig) |
+| Mailing list | [looking for a new home, suggestions welcome](https://gitlab.freedesktop.org/freedesktop/freedesktop/-/issues/1082) |
+| Patreon | [purpleidea](https://www.patreon.com/purpleidea) on Patreon |
 
 ## Status:
-Mgmt is a fairly new project.
-We're working towards being minimally useful for production environments.
-We aren't feature complete for what we'd consider a 1.x release yet.
-With your help you'll be able to influence our design and get us there sooner!
 
-## Questions:
-Please join the [#mgmtconfig](https://webchat.freenode.net/?channels=#mgmtconfig) IRC community!
-If you have a well phrased question that might benefit others, consider asking it by sending a patch to the documentation [FAQ](https://github.com/purpleidea/mgmt/blob/master/DOCUMENTATION.md#usage-and-frequently-asked-questions) section. I'll merge your question, and a patch with the answer!
+Mgmt is a next generation automation tool. It has similarities to other tools in
+the configuration management space, but has a fast, modern, distributed systems
+approach. The project contains an engine and a language.
+[Please have a look at an introductory video or blog post.](docs/on-the-web.md)
 
-## Quick start:
-* Make sure you have golang version 1.6 or greater installed.
-* If you do not have a GOPATH yet, create one and export it:
-```
-mkdir $HOME/gopath
-export GOPATH=$HOME/gopath
-```
-* You might also want to add the GOPATH to your `~/.bashrc` or `~/.profile`.
-* For more information you can read the [GOPATH documentation](https://golang.org/cmd/go/#hdr-GOPATH_environment_variable).
-* Next download the mgmt code base, and switch to that directory:
-```
-go get -u github.com/purpleidea/mgmt
-cd $GOPATH/src/github.com/purpleidea/mgmt
-```
-* Get the remaining golang deps with `go get ./...`, or run `make deps` if you're comfortable with how we install them.
-* Run `make build` to get a freshly built `mgmt` binary.
-* Run `time ./mgmt run --yaml examples/graph0.yaml --converged-timeout=5 --tmp-prefix` to try out a very simple example!
-* To run continuously in the default mode of operation, omit the `--converged-timeout` option.
-* Have fun hacking on our future technology!
+Mgmt is over ten years old! It is very powerful today, and has a solid
+foundation and architecture which has been polished over the years. As with all
+software, there are bugs to fix and improvements to be made, but I expect
+they're easy to hack through and fix if you find any. Interested users should
+start with the [official website](https://mgmtconfig.com/docs/).
 
-## Examples:
-Please look in the [examples/](examples/) folder for more examples!
+## Sponsors:
+
+Mgmt is generously sponsored by:
+
+[![m9rx corporation](art/m9rx.png)](https://m9rx.com/)
+
+Please reach out if you'd like to sponsor!
 
 ## Documentation:
-Please see: the manually created [DOCUMENTATION.md](DOCUMENTATION.md) (also available as [PDF](https://pdfdoc-purpleidea.rhcloud.com/pdf/https://github.com/purpleidea/mgmt/blob/master/DOCUMENTATION.md)) and the automatically generated [GoDoc documentation](https://godoc.org/github.com/purpleidea/mgmt).
 
-## Roadmap:
-Please see: [TODO.md](TODO.md) for a list of upcoming work and TODO items.
-Please get involved by working on one of these items or by suggesting something else!
-Feel free to grab one of the straightforward [#mgmtlove](https://github.com/purpleidea/mgmt/labels/mgmtlove) issues if you're a first time contributor to the project or if you're unsure about what to hack on!
+Please read, enjoy and help improve our documentation!
+
+| Documentation | Additional Notes |
+|---|---|
+| [quick start guide](docs/quick-start-guide.md) | for everyone |
+| [frequently asked questions](docs/faq.md) | for everyone |
+| [general documentation](docs/documentation.md) | for everyone |
+| [resource reference](https://mgmtconfig.com/docs/resources/) | for everyone |
+| [function reference](https://mgmtconfig.com/docs/functions/) | for everyone |
+| [language guide](docs/language-guide.md) | for everyone |
+| [function guide](docs/function-guide.md) | for mgmt developers |
+| [resource guide](docs/resource-guide.md) | for mgmt developers |
+| [style guide](docs/style-guide.md) | for mgmt developers |
+| [contributing guide](docs/contributing.md) | for mgmt contributors |
+| [service API guide](docs/service-guide.md) | for external developers |
+| [godoc API reference](https://godoc.org/github.com/purpleidea/mgmt) | for mgmt developers |
+| [prometheus guide](docs/prometheus.md) | for everyone |
+| [puppet guide](docs/puppet-guide.md) | for puppet sysadmins |
+| [development](docs/development.md) | for mgmt developers |
+| [videos](docs/on-the-web.md) | for everyone |
+| [blogs](docs/on-the-web.md) | for everyone |
+
+## Questions:
+
+Please ask in the [community](#community)!
+If you have a well phrased question that might benefit others, consider asking
+it by sending a patch to the [FAQ](docs/faq.md) section. I'll merge your
+question, and a patch with the answer!
+
+## Get involved:
+
+Feel free to grab one of the straightforward [#mgmtlove](https://github.com/purpleidea/mgmt/labels/mgmtlove)
+issues if you're a first time contributor to the project or if you're unsure
+about what to hack on! Please get involved by working on one of these items or
+by suggesting something else! There are some lower priority issues and harder
+issues available in our [TODO](TODO.md) file. Please have a look.
 
 ## Bugs:
-Please set the `DEBUG` constant in [main.go](https://github.com/purpleidea/mgmt/blob/master/main.go) to `true`, and post the logs when you report the [issue](https://github.com/purpleidea/mgmt/issues).
-Bonus points if you provide a [shell](https://github.com/purpleidea/mgmt/tree/master/test/shell) or [OMV](https://github.com/purpleidea/mgmt/tree/master/test/omv) reproducible test case.
-Feel free to read my article on [debugging golang programs](https://ttboj.wordpress.com/2016/02/15/debugging-golang-programs/).
 
-## Dependencies:
-* golang 1.6 or higher (required, available in most distros)
-* golang libraries (required, available with `go get`)
-```
-go get github.com/coreos/etcd/client
-go get gopkg.in/yaml.v2
-go get gopkg.in/fsnotify.v1
-go get github.com/urfave/cli
-go get github.com/coreos/go-systemd/dbus
-go get github.com/coreos/go-systemd/util
-go get github.com/coreos/pkg/capnslog
-go get github.com/rgbkrk/libvirt-go
-```
-* stringer (optional for building), available as a package on some platforms, otherwise via `go get`
-```
-go get golang.org/x/tools/cmd/stringer
-```
-* pandoc (optional, for building a pdf of the documentation)
-* graphviz (optional, for building a visual representation of the graph)
+Please set the `DEBUG` constant in [main.go](https://github.com/purpleidea/mgmt/blob/master/main.go)
+to `true`, and post the logs when you report the [issue](https://github.com/purpleidea/mgmt/issues).
+Feel free to read my article on [debugging golang programs](https://purpleidea.com/blog/2016/02/15/debugging-golang-programs/).
 
 ## Patches:
+
 We'd love to have your patches! Please send them by email, or as a pull request.
 
 ## On the web:
-* James Shubin; blog: [Next generation configuration mgmt](https://ttboj.wordpress.com/2016/01/18/next-generation-configuration-mgmt/)
-* James Shubin; video: [Introductory recording from DevConf.cz 2016](https://www.youtube.com/watch?v=GVhpPF0j-iE&html5=1)
-* James Shubin; video: [Introductory recording from CfgMgmtCamp.eu 2016](https://www.youtube.com/watch?v=fNeooSiIRnA&html5=1)
-* Julian Dunn; video: [On mgmt at CfgMgmtCamp.eu 2016](https://www.youtube.com/watch?v=kfF9IATUask&t=1949&html5=1)
-* Walter Heck; slides: [On mgmt at CfgMgmtCamp.eu 2016](http://www.slideshare.net/olindata/configuration-management-time-for-a-4th-generation/3)
-* Marco Marongiu; blog: [On mgmt](http://syslog.me/2016/02/15/leap-or-die/)
-* Felix Frank; blog: [From Catalog To Mgmt (on puppet to mgmt "transpiling")](https://ffrank.github.io/features/2016/02/18/from-catalog-to-mgmt/)
-* James Shubin; blog: [Automatic edges in mgmt (...and the pkg resource)](https://ttboj.wordpress.com/2016/03/14/automatic-edges-in-mgmt/)
-* James Shubin; blog: [Automatic grouping in mgmt](https://ttboj.wordpress.com/2016/03/30/automatic-grouping-in-mgmt/)
-* John Arundel; tweet: [“Puppet’s days are numbered.”](https://twitter.com/bitfield/status/732157519142002688)
-* Felix Frank; blog: [Puppet, Meet Mgmt (on puppet to mgmt internals)](https://ffrank.github.io/features/2016/06/12/puppet,-meet-mgmt/)
-* Felix Frank; blog: [Puppet Powered Mgmt (puppet to mgmt tl;dr)](https://ffrank.github.io/features/2016/06/19/puppet-powered-mgmt/)
-* James Shubin; blog: [Automatic clustering in mgmt](https://ttboj.wordpress.com/2016/06/20/automatic-clustering-in-mgmt/)
-* James Shubin; video: [Recording from CoreOSFest 2016](https://www.youtube.com/watch?v=KVmDCUA42wc&html5=1)
-* James Shubin; video: [Recording from DebConf16](http://meetings-archive.debian.net/pub/debian-meetings/2016/debconf16/Next_Generation_Config_Mgmt.webm) ([Slides](https://annex.debconf.org//debconf-share/debconf16/slides/15-next-generation-config-mgmt.pdf))
-* Felix Frank; blog: [Edging It All In (puppet and mgmt edges)](https://ffrank.github.io/features/2016/07/12/edging-it-all-in/)
-* Felix Frank; blog: [Translating All The Things (puppet to mgmt translation warnings)](https://ffrank.github.io/features/2016/08/19/translating-all-the-things/)
-* James Shubin; video: [Recording from systemd.conf 2016](https://www.youtube.com/watch?v=jB992Zb3nH0&html5=1)
-* James Shubin; blog: [Remote execution in mgmt](https://ttboj.wordpress.com/2016/10/07/remote-execution-in-mgmt/)
-* James Shubin; video: [Recording from High Load Strategy 2016](https://vimeo.com/191493409)
-* James Shubin; video: [Recording from NLUUG 2016](https://www.youtube.com/watch?v=MmpwOQAb_SE&html5=1)
-* James Shubin; blog: [Send/Recv in mgmt](https://ttboj.wordpress.com/2016/12/07/sendrecv-in-mgmt/)
 
-##
+[Blog posts and recorded talks about mgmt are listed here!](docs/on-the-web.md)
 
 Happy hacking!

TODO.md

@@ -1,67 +1,90 @@
 # TODO
-If you're looking for something to do, look here!
-Let us know if you're working on one of the items.
+
+Here is a TODO list of longstanding items that are either lower-priority, or
+more involved in terms of time, skill-level, and/or motivation.
+
+Please have a look, and let us know if you're working on one of the items. It's
+best to open an issue to track your progress and to discuss any implementation
+questions you might have.
+
+Lastly, if you'd like something different to work on, please ping @purpleidea
+and I'll create an issue tailored especially for your approximate golang skill
+level and available time commitment in terms of hours you'd need to spend on the
+patch.
+
+Happy Hacking!
 
 ## Package resource
+
 - [ ] getfiles support on debian [bug](https://github.com/hughsie/PackageKit/issues/118)
 - [ ] directory info on fedora [bug](https://github.com/hughsie/PackageKit/issues/117)
 - [ ] dnf blocker [bug](https://github.com/hughsie/PackageKit/issues/110)
-- [ ] install signal blocker [bug](https://github.com/hughsie/PackageKit/issues/109)
 
-## File resource [bug](https://github.com/purpleidea/mgmt/issues/13) [:heart:](https://github.com/purpleidea/mgmt/labels/mgmtlove)
-- [ ] chown/chmod support [:heart:](https://github.com/purpleidea/mgmt/labels/mgmtlove)
-- [ ] user/group support [:heart:](https://github.com/purpleidea/mgmt/labels/mgmtlove)
+## File resource [bug](https://github.com/purpleidea/mgmt/issues/64) [:heart:](https://github.com/purpleidea/mgmt/labels/mgmtlove)
+
 - [ ] recurse limit support [:heart:](https://github.com/purpleidea/mgmt/labels/mgmtlove)
 - [ ] fanotify support [bug](https://github.com/go-fsnotify/fsnotify/issues/114)
 
 ## Svc resource
-- [ ] base resource improvements
+
+- [ ] refreshonly support [:heart:](https://github.com/purpleidea/mgmt/issues/464)
 
 ## Exec resource
+
 - [ ] base resource improvements
 
 ## Timer resource
-- [ ] reset on recompile
+
 - [ ] increment algorithm (linear, exponential, etc...) [:heart:](https://github.com/purpleidea/mgmt/labels/mgmtlove)
 
 ## User/Group resource
-- [ ] base resource [:heart:](https://github.com/purpleidea/mgmt/labels/mgmtlove)
+
 - [ ] automatic edges to file resource [:heart:](https://github.com/purpleidea/mgmt/labels/mgmtlove)
 
-## Virt (libvirt) resource
-- [ ] base resource [bug](https://github.com/purpleidea/mgmt/issues/25)
-
-## Net (systemd-networkd) resource
-- [ ] base resource
-
-## Nspawn (systemd-nspawn) resource
-- [ ] base resource [:heart:](https://github.com/purpleidea/mgmt/labels/mgmtlove)
-
-## Mount (systemd-mount) resource
-- [ ] base resource [:heart:](https://github.com/purpleidea/mgmt/labels/mgmtlove)
-
-## Cron (systemd-timer) resource
-- [ ] base resource [:heart:](https://github.com/purpleidea/mgmt/labels/mgmtlove)
-
 ## Http resource
-- [ ] base resource
+
+- [ ] base resource [:heart:](https://github.com/purpleidea/mgmt/labels/mgmtlove)
 
 ## Etcd improvements
-- [ ] fix embedded etcd master race
+
+- [ ] fix etcd race bug that only happens during CI testing (intermittently
+failing test case issue)
 
 ## Torrent/dht file transfer
+
 - [ ] base plumbing
 
+## GPG/Auth improvements
+
+- [ ] base plumbing
+
+## Resource improvements
+
+- [ ] more reversible resources implemented
+- [ ] more "cloud" resources
+
 ## Language improvements
-- [ ] language design
-- [ ] lexer/parser
+
+- [ ] more core functions
 - [ ] automatic language formatter, ala `gofmt`
 - [ ] gedit/gnome-builder/gtksourceview syntax highlighting
 - [ ] vim syntax highlighting
-- [ ] emacs syntax highlighting
+- [ ] emacs syntax highlighting: see `misc/emacs/` (needs updating)
+- [ ] exposed $error variable for feedback in the language
+- [ ] improve the printf function to add %[]s, %[]f ([]str, []float) and map,
+struct, nested etc... %v would be nice too!
+- [ ] add line/col/file annotations to AST so we can get locations of errors
+that the parser finds
+- [ ] add more error messages with the `%error` pattern in parser.y
+- [ ] we should have helper functions or language sugar to pull a field out of a
+struct, or a value out of a map, or an index out of a list, etc...
+
+## Engine improvements
+
+- [ ] add a "waiting for func" message in the func engine to notify the user
+about slow functions...
 
 ## Other
-- [ ] better error/retry handling
-- [ ] deb package target in Makefile
+
 - [ ] reproducible builds
 - [ ] add your suggestions!

Vagrantfile

@@ -0,0 +1,51 @@
+Vagrant.configure(2) do |config|
+	config.ssh.forward_agent = true
+	config.ssh.username = 'vagrant'
+	config.vm.network "private_network", ip: "192.168.219.2"
+
+	config.vm.synced_folder ".", "/vagrant", disabled: true
+
+	config.vm.define "mgmt-dev" do |instance|
+		instance.vm.box = "bento/fedora-31"
+	end
+
+	config.vm.provider "virtualbox" do |v|
+		v.memory = 1536
+		v.cpus = 2
+	end
+	config.vm.provider "libvirt" do |v|
+		v.memory = 2048
+	end
+
+	config.vm.provision "file", source: "vagrant/motd", destination: ".motd"
+	config.vm.provision "shell", inline: "cp ~vagrant/.motd /etc/motd"
+
+	config.vm.provision "file", source: "vagrant/mgmt.bashrc", destination: ".mgmt.bashrc"
+	config.vm.provision "file", source: "~/.gitconfig", destination: ".gitconfig"
+
+	config.vm.provision "shell", inline: "dnf install -y golang git make"
+
+	# set up packagekit
+	config.vm.provision "shell" do |shell|
+		shell.inline = <<-SCRIPT
+			dnf install -y PackageKit
+			systemctl enable packagekit
+			systemctl start packagekit
+		SCRIPT
+	end
+
+	# set up vagrant home
+	script = <<-SCRIPT
+		grep -q 'mgmt\.bashrc' ~/.bashrc || echo '. ~/.mgmt.bashrc' >>~/.bashrc
+		. ~/.mgmt.bashrc
+		mkdir -p ~/gopath/src/github.com/purpleidea
+		cd ~/gopath/src/github.com/purpleidea
+		git clone https://github.com/purpleidea/mgmt --recursive
+		cd mgmt
+		make deps
+	SCRIPT
+	config.vm.provision "shell" do |shell|
+		shell.privileged = false
+		shell.inline = script
+	end
+end

cli/cli.go

@@ -0,0 +1,189 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+// Package cli handles all of the core command line parsing. It's the first
+// entry point after the real main function, and it imports and runs our core
+// "lib".
+package cli
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	cliUtil "github.com/purpleidea/mgmt/cli/util"
+	"github.com/purpleidea/mgmt/util/errwrap"
+
+	"github.com/alexflint/go-arg"
+)
+
+func init() {
+	if _, err := arg.NewParser(arg.Config{}, &Args{}); err != nil { // sanity check
+		panic(errwrap.Wrapf(err, "invalid args cli struct"))
+	}
+}
+
+// CLI is the entry point for using mgmt normally from the CLI.
+func CLI(ctx context.Context, data *cliUtil.Data) error {
+	// test for sanity
+	if data == nil {
+		return fmt.Errorf("this CLI was not run correctly")
+	}
+	if data.Program == "" || data.Version == "" {
+		return fmt.Errorf("program was not compiled correctly")
+	}
+	if data.Copying == "" {
+		return fmt.Errorf("program copyrights were removed, can't run")
+	}
+
+	args := Args{}
+	args.version = data.Version // copy this in
+	args.description = data.Tagline
+
+	config := arg.Config{
+		Program: data.Program,
+	}
+	parser, err := arg.NewParser(config, &args)
+	if err != nil {
+		// programming error
+		return errwrap.Wrapf(err, "cli config error")
+	}
+	err = parser.Parse(data.Args[1:]) // XXX: args[0] needs to be dropped
+	if err == arg.ErrHelp {
+		parser.WriteHelp(os.Stdout)
+		return nil
+	}
+	if err == arg.ErrVersion {
+		fmt.Printf("%s\n", data.Version) // byon: bring your own newline
+		return nil
+	}
+	if err != nil {
+		//parser.WriteHelp(os.Stdout) // TODO: is doing this helpful?
+		return cliUtil.CliParseError(err) // consistent errors
+	}
+
+	// display the license
+	if args.License {
+		fmt.Printf("%s", data.Copying) // file comes with a trailing nl
+		return nil
+	}
+
+	if ok, err := args.Run(ctx, data); err != nil {
+		return err
+	} else if ok { // did we activate one of the commands?
+		return nil
+	}
+
+	// print help if no subcommands are set
+	parser.WriteHelp(os.Stdout)
+
+	return nil
+}
+
+// Args is the CLI parsing structure and type of the parsed result. This
+// particular struct is the top-most one.
+type Args struct {
+	// XXX: We cannot have both subcommands and a positional argument.
+	// XXX: I think it's a bug of this library that it can't handle argv[0].
+	//Argv0 string `arg:"positional"`
+
+	License bool `arg:"--license" help:"display the license and exit"`
+
+	RunCmd *RunArgs `arg:"subcommand:run" help:"run code on this machine"`
+
+	DeployCmd *DeployArgs `arg:"subcommand:deploy" help:"deploy code into a cluster"`
+
+	SetupCmd *SetupArgs `arg:"subcommand:setup" help:"setup some bootstrapping tasks"`
+
+	FirstbootCmd *FirstbootArgs `arg:"subcommand:firstboot" help:"run some tasks on first boot"`
+
+	DocsCmd *DocsGenerateArgs `arg:"subcommand:docs" help:"generate documentation"`
+
+	ToolsCmd *ToolsArgs `arg:"subcommand:tools" help:"collection of useful tools"`
+
+	// This never runs, it gets preempted in the real main() function.
+	// XXX: Can we do it nicely with the new arg parser? can it ignore all args?
+	EtcdCmd *EtcdArgs `arg:"subcommand:etcd" help:"run standalone etcd"`
+
+	// version is a private handle for our version string.
+	version string `arg:"-"` // ignored from parsing
+
+	// description is a private handle for our description string.
+	description string `arg:"-"` // ignored from parsing
+}
+
+// Version returns the version string. Implementing this signature is part of
+// the API for the cli library.
+func (obj *Args) Version() string {
+	return obj.version
+}
+
+// Description returns a description string. Implementing this signature is part
+// of the API for the cli library.
+func (obj *Args) Description() string {
+	return obj.description
+}
+
+// Run executes the correct subcommand. It errors if there's ever an error. It
+// returns true if we did activate one of the subcommands. It returns false if
+// we did not. This information is used so that the top-level parser can return
+// usage or help information if no subcommand activates.
+func (obj *Args) Run(ctx context.Context, data *cliUtil.Data) (bool, error) {
+	if cmd := obj.RunCmd; cmd != nil {
+		return cmd.Run(ctx, data)
+	}
+
+	if cmd := obj.DeployCmd; cmd != nil {
+		return cmd.Run(ctx, data)
+	}
+
+	if cmd := obj.SetupCmd; cmd != nil {
+		return cmd.Run(ctx, data)
+	}
+
+	if cmd := obj.FirstbootCmd; cmd != nil {
+		return cmd.Run(ctx, data)
+	}
+
+	if cmd := obj.DocsCmd; cmd != nil {
+		return cmd.Run(ctx, data)
+	}
+
+	if cmd := obj.ToolsCmd; cmd != nil {
+		return cmd.Run(ctx, data)
+	}
+
+	// NOTE: we could return true, fmt.Errorf("...") if more than one did
+	return false, nil // nobody activated
+}
+
+// EtcdArgs is the CLI parsing structure and type of the parsed result. This
+// particular one is empty because the `etcd` subcommand is preempted in the
+// real main() function.
+type EtcdArgs struct{}

cli/deploy.go

@@ -0,0 +1,314 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+package cli
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/signal"
+
+	cliUtil "github.com/purpleidea/mgmt/cli/util"
+	"github.com/purpleidea/mgmt/engine"
+	"github.com/purpleidea/mgmt/etcd"
+	"github.com/purpleidea/mgmt/etcd/client"
+	etcdfs "github.com/purpleidea/mgmt/etcd/fs"
+	etcdSSH "github.com/purpleidea/mgmt/etcd/ssh"
+	"github.com/purpleidea/mgmt/gapi"
+	"github.com/purpleidea/mgmt/lib"
+	"github.com/purpleidea/mgmt/util"
+	"github.com/purpleidea/mgmt/util/errwrap"
+
+	git "github.com/go-git/go-git/v5"
+	"github.com/google/uuid"
+)
+
+// DeployArgs is the CLI parsing structure and type of the parsed result. This
+// particular one contains all the common flags for the `deploy` subcommand
+// which all frontends can use.
+type DeployArgs struct {
+	// SSHURL can be specified if we want to transport the SSH client
+	// connection over SSH. If this is specified, the second hop is made
+	// with the Seeds values, but they connect from this destination. You
+	// can specify this in the standard james@server:22 format. This will
+	// use your ~/.ssh/ directory for public key authentication and
+	// verifying the host key in the known_hosts file. This must already be
+	// setup for things to work.
+	SSHURL string `arg:"--ssh-url" help:"transport the etcd client connection over SSH to this server"`
+
+	// SSHHostKey is the key part (which is already base64 encoded) from a
+	// known_hosts file, representing the host we're connecting to. If this
+	// is specified, then it overrides looking for it in the URL.
+	SSHHostKey string `arg:"--ssh-hostkey" help:"use this ssh known hosts key when connecting over SSH"`
+
+	Seeds []string `arg:"--seeds,separate,env:MGMT_SEEDS" help:"default etcd client endpoints"`
+	Noop  bool     `arg:"--noop" help:"globally force all resources into no-op mode"`
+	Sema  int      `arg:"--sema" default:"-1" help:"globally add a semaphore to all resources with this lock count"`
+	NoGit bool     `arg:"--no-git" help:"don't look at git commit id for safe deploys"`
+	Force bool     `arg:"--force" help:"force a new deploy, even if the safety chain would break"`
+
+	NoAutoEdges bool `arg:"--no-autoedges" help:"skip the autoedges stage"`
+
+	DeployEmpty      *cliUtil.EmptyArgs      `arg:"subcommand:empty" help:"deploy empty payload"`
+	DeployLang       *cliUtil.LangArgs       `arg:"subcommand:lang" help:"deploy lang (mcl) payload"`
+	DeployYaml       *cliUtil.YamlArgs       `arg:"subcommand:yaml" help:"deploy yaml graph payload"`
+	DeployPuppet     *cliUtil.PuppetArgs     `arg:"subcommand:puppet" help:"deploy puppet graph payload"`
+	DeployLangPuppet *cliUtil.LangPuppetArgs `arg:"subcommand:langpuppet" help:"deploy langpuppet graph payload"`
+}
+
+// Run executes the correct subcommand. It errors if there's ever an error. It
+// returns true if we did activate one of the subcommands. It returns false if
+// we did not. This information is used so that the top-level parser can return
+// usage or help information if no subcommand activates. This particular Run is
+// the run for the main `deploy` subcommand. This always requires a frontend to
+// deploy to the cluster, but if you don't want a graph, you can use the `empty`
+// frontend. The engine backend is agnostic to which frontend is deployed, in
+// fact, you can deploy with multiple different frontends, one after another, on
+// the same engine.
+func (obj *DeployArgs) Run(ctx context.Context, data *cliUtil.Data) (bool, error) {
+	var name string
+	var args interface{}
+	if cmd := obj.DeployEmpty; cmd != nil {
+		name = cliUtil.LookupSubcommand(obj, cmd) // "empty"
+		args = cmd
+	}
+	if cmd := obj.DeployLang; cmd != nil {
+		name = cliUtil.LookupSubcommand(obj, cmd) // "lang"
+		args = cmd
+	}
+	if cmd := obj.DeployYaml; cmd != nil {
+		name = cliUtil.LookupSubcommand(obj, cmd) // "yaml"
+		args = cmd
+	}
+	if cmd := obj.DeployPuppet; cmd != nil {
+		name = cliUtil.LookupSubcommand(obj, cmd) // "puppet"
+		args = cmd
+	}
+	if cmd := obj.DeployLangPuppet; cmd != nil {
+		name = cliUtil.LookupSubcommand(obj, cmd) // "langpuppet"
+		args = cmd
+	}
+
+	// XXX: workaround https://github.com/alexflint/go-arg/issues/239
+	gapiNames := gapi.Names() // list of registered names
+	if l := len(obj.Seeds); name == "" && l > 1 {
+		elem := obj.Seeds[l-2] // second to last element
+		if util.StrInList(elem, gapiNames) {
+			return false, cliUtil.CliParseError(cliUtil.MissingEquals) // consistent errors
+		}
+	}
+
+	fn, exists := gapi.RegisteredGAPIs[name]
+	if !exists {
+		return false, nil // did not activate
+	}
+	gapiObj := fn()
+
+	program, version := data.Program, data.Version
+	Logf := func(format string, v ...interface{}) {
+		data.Flags.Logf("deploy: "+format, v...)
+	}
+
+	// TODO: consider adding a timeout based on an args.Timeout flag ?
+	ctx, cancel := signal.NotifyContext(ctx, os.Interrupt)
+	defer cancel()
+
+	cliUtil.Hello(program, version, data.Flags) // say hello!
+	defer Logf("goodbye!")
+
+	var hash, pHash string
+	if !obj.NoGit {
+		wd, err := os.Getwd()
+		if err != nil {
+			return false, errwrap.Wrapf(err, "could not get current working directory")
+		}
+		repo, err := git.PlainOpen(wd)
+		if err != nil {
+			return false, errwrap.Wrapf(err, "could not open git repo")
+		}
+
+		head, err := repo.Head()
+		if err != nil {
+			return false, errwrap.Wrapf(err, "could not read git HEAD")
+		}
+
+		hash = head.Hash().String() // current commit id
+		Logf("hash: %s", hash)
+
+		lo := &git.LogOptions{
+			From: head.Hash(),
+		}
+		commits, err := repo.Log(lo)
+		if err != nil {
+			return false, errwrap.Wrapf(err, "could not read git log")
+		}
+		if _, err := commits.Next(); err != nil { // skip over HEAD
+			return false, errwrap.Wrapf(err, "could not read HEAD in git log") // weird!
+		}
+		commit, err := commits.Next()
+		if err == nil { // errors are okay, we might be empty
+			pHash = commit.Hash.String() // previous commit id
+		}
+		Logf("previous deploy hash: %s", pHash)
+		if obj.Force {
+			pHash = "" // don't check this :(
+		}
+		if hash == "" {
+			return false, errwrap.Wrapf(err, "could not get git deploy hash")
+		}
+	}
+
+	uniqueid := uuid.New() // panic's if it can't generate one :P
+
+	etcdClient := client.NewClientFromSeedsNamespace(
+		obj.Seeds, // endpoints
+		lib.NS,
+	)
+	if err := etcdClient.Init(); err != nil {
+		return false, errwrap.Wrapf(err, "client Init failed")
+	}
+	defer func() {
+		err := errwrap.Wrapf(etcdClient.Close(), "client Close failed")
+		if err != nil {
+			// TODO: cause the final exit code to be non-zero
+			Logf("client cleanup error: %+v", err)
+		}
+	}()
+
+	var world engine.World
+	world = &etcd.World{ // XXX: What should some of these fields be?
+		Client: etcdClient, // XXX: remove me when etcdfs below is done
+		Seeds:  obj.Seeds,
+		NS:     lib.NS,
+		//MetadataPrefix: lib.MetadataPrefix,
+		//StoragePrefix:  lib.StoragePrefix,
+		//StandaloneFs: ???.DeployFs, // used for static deploys
+		//GetURI: func() string {
+		//},
+	}
+	if obj.SSHURL != "" { // alternate world implementation over SSH
+		world = &etcdSSH.World{
+			URL:     obj.SSHURL,
+			HostKey: obj.SSHHostKey,
+			Seeds:   obj.Seeds,
+			NS:      lib.NS,
+			//MetadataPrefix: lib.MetadataPrefix,
+			//StoragePrefix:  lib.StoragePrefix,
+			//StandaloneFs: ???.DeployFs, // used for static deploys
+			//GetURI: func() string {
+			//},
+		}
+		// XXX: We need to first get rid of the standalone etcd client,
+		// and then pull the etcdfs stuff in so it uses that client.
+		return false, fmt.Errorf("--ssh-url is not implemented yet")
+	}
+	worldInit := &engine.WorldInit{
+		Hostname: "", // XXX: Should we set this?
+		Debug:    data.Flags.Debug,
+		Logf: func(format string, v ...interface{}) {
+			Logf("world: etcd: "+format, v...)
+		},
+	}
+	if err := world.Connect(ctx, worldInit); err != nil {
+		return false, errwrap.Wrapf(err, "world Connect failed")
+	}
+	defer func() {
+		err := errwrap.Wrapf(world.Cleanup(), "world Cleanup failed")
+		if err != nil {
+			// TODO: cause the final exit code to be non-zero?
+			Logf("close error: %+v", err)
+		}
+	}()
+
+	// get max id (from all the previous deploys)
+	max, err := world.GetMaxDeployID(ctx)
+	if err != nil {
+		return false, errwrap.Wrapf(err, "error getting max deploy id")
+	}
+	// find the latest id
+	var id = max + 1 // next id
+	Logf("previous max deploy id: %d", max)
+
+	// XXX: Get this from the World API? (Which might need improving!)
+	etcdFs := &etcdfs.Fs{
+		Client: etcdClient,
+		// TODO: using a uuid is meant as a temporary measure, i hate them
+		Metadata:   lib.MetadataPrefix + fmt.Sprintf("/deploy/%d-%s", id, uniqueid),
+		DataPrefix: lib.StoragePrefix,
+
+		Debug: data.Flags.Debug,
+		Logf: func(format string, v ...interface{}) {
+			Logf("fs: "+format, v...)
+		},
+	}
+
+	info := &gapi.Info{
+		Args: args,
+		Flags: &gapi.Flags{
+			Noop: obj.Noop,
+			Sema: obj.Sema,
+			//Update: obj.Update,
+		},
+
+		Fs:    etcdFs,
+		Debug: data.Flags.Debug,
+		Logf: func(format string, v ...interface{}) {
+			// TODO: is this a sane prefix to use here?
+			data.Flags.Logf("cli: "+format, v...)
+		},
+	}
+
+	deploy, err := gapiObj.Cli(info)
+	if err != nil {
+		return false, cliUtil.CliParseError(err) // consistent errors
+	}
+	if deploy == nil { // not used
+		return false, fmt.Errorf("not enough information specified")
+	}
+
+	// redundant
+	deploy.Noop = obj.Noop
+	deploy.Sema = obj.Sema
+
+	deploy.NoAutoEdges = obj.NoAutoEdges
+
+	str, err := deploy.ToB64()
+	if err != nil {
+		return false, errwrap.Wrapf(err, "encoding error")
+	}
+
+	Logf("pushing...")
+	// this nominally checks the previous git hash matches our expectation
+	if err := world.AddDeploy(ctx, id, hash, pHash, &str); err != nil {
+		return false, errwrap.Wrapf(err, "could not create deploy id `%d`", id)
+	}
+	Logf("success, id: %d", id)
+	return true, nil
+}

cli/docs.go

@@ -0,0 +1,150 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+package cli
+
+import (
+	"context"
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+
+	cliUtil "github.com/purpleidea/mgmt/cli/util"
+	"github.com/purpleidea/mgmt/docs"
+)
+
+// DocsGenerateArgs is the CLI parsing structure and type of the parsed result.
+// This particular one contains all the common flags for the `docs generate`
+// subcommand.
+type DocsGenerateArgs struct {
+	docs.Config // embedded config (can't be a pointer) https://github.com/alexflint/go-arg/issues/240
+
+	DocsGenerate *cliUtil.DocsGenerateArgs `arg:"subcommand:generate" help:"generate documentation"`
+}
+
+// Run executes the correct subcommand. It errors if there's ever an error. It
+// returns true if we did activate one of the subcommands. It returns false if
+// we did not. This information is used so that the top-level parser can return
+// usage or help information if no subcommand activates. This particular Run is
+// the run for the main `docs` subcommand.
+func (obj *DocsGenerateArgs) Run(ctx context.Context, data *cliUtil.Data) (bool, error) {
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	var name string
+	var args interface{}
+	if cmd := obj.DocsGenerate; cmd != nil {
+		name = cliUtil.LookupSubcommand(obj, cmd) // "generate"
+		args = cmd
+	}
+	_ = name
+
+	Logf := func(format string, v ...interface{}) {
+		// Don't block this globally...
+		//if !data.Flags.Debug {
+		//	return
+		//}
+		data.Flags.Logf("main: "+format, v...)
+	}
+
+	var api docs.API
+
+	if cmd := obj.DocsGenerate; cmd != nil {
+		api = &docs.Generate{
+			DocsGenerateArgs: args.(*cliUtil.DocsGenerateArgs),
+			Config:           obj.Config,
+			Program:          data.Program,
+			Version:          data.Version,
+			Debug:            data.Flags.Debug,
+			Logf:             Logf,
+		}
+	}
+
+	if api == nil {
+		return false, nil // nothing found (display help!)
+	}
+
+	// We don't use these for the setup command in normal operation.
+	if data.Flags.Debug {
+		cliUtil.Hello(data.Program, data.Version, data.Flags) // say hello!
+		defer Logf("goodbye!")
+	}
+
+	// install the exit signal handler
+	wg := &sync.WaitGroup{}
+	defer wg.Wait()
+	exit := make(chan struct{})
+	defer close(exit)
+	wg.Add(1)
+	go func() {
+		defer cancel()
+		defer wg.Done()
+		// must have buffer for max number of signals
+		signals := make(chan os.Signal, 3+1) // 3 * ^C + 1 * SIGTERM
+		signal.Notify(signals, os.Interrupt) // catch ^C
+		//signal.Notify(signals, os.Kill) // catch signals
+		signal.Notify(signals, syscall.SIGTERM)
+		var count uint8
+		for {
+			select {
+			case sig := <-signals: // any signal will do
+				if sig != os.Interrupt {
+					data.Flags.Logf("interrupted by signal")
+					return
+				}
+
+				switch count {
+				case 0:
+					data.Flags.Logf("interrupted by ^C")
+					cancel()
+				case 1:
+					data.Flags.Logf("interrupted by ^C (fast pause)")
+					cancel()
+				case 2:
+					data.Flags.Logf("interrupted by ^C (hard interrupt)")
+					cancel()
+				}
+				count++
+
+			case <-exit:
+				return
+			}
+		}
+	}()
+
+	if err := api.Main(ctx); err != nil {
+		if data.Flags.Debug {
+			data.Flags.Logf("main: %+v", err)
+		}
+		return false, err
+	}
+
+	return true, nil
+}

cli/firstboot.go

@@ -0,0 +1,151 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+package cli
+
+import (
+	"context"
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+
+	cliUtil "github.com/purpleidea/mgmt/cli/util"
+	"github.com/purpleidea/mgmt/firstboot"
+)
+
+// FirstbootArgs is the CLI parsing structure and type of the parsed result.
+// This particular one contains all the common flags for the `firstboot`
+// subcommand.
+type FirstbootArgs struct {
+	firstboot.Config // embedded config (can't be a pointer) https://github.com/alexflint/go-arg/issues/240
+
+	FirstbootStart *cliUtil.FirstbootStartArgs `arg:"subcommand:start" help:"start firstboot service"`
+}
+
+// Run executes the correct subcommand. It errors if there's ever an error. It
+// returns true if we did activate one of the subcommands. It returns false if
+// we did not. This information is used so that the top-level parser can return
+// usage or help information if no subcommand activates. This particular Run is
+// the run for the main `firstboot` subcommand. The firstboot command as a
+// service that lets you run commands once on the first boot of a system.
+func (obj *FirstbootArgs) Run(ctx context.Context, data *cliUtil.Data) (bool, error) {
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	var name string
+	var args interface{}
+	if cmd := obj.FirstbootStart; cmd != nil {
+		name = cliUtil.LookupSubcommand(obj, cmd) // "pkg"
+		args = cmd
+	}
+	_ = name
+
+	Logf := func(format string, v ...interface{}) {
+		// Don't block this globally...
+		//if !data.Flags.Debug {
+		//	return
+		//}
+		data.Flags.Logf("main: "+format, v...)
+	}
+
+	var api firstboot.API
+
+	if cmd := obj.FirstbootStart; cmd != nil {
+		api = &firstboot.Start{
+			FirstbootStartArgs: args.(*cliUtil.FirstbootStartArgs),
+			Config:             obj.Config,
+			Program:            data.Program,
+			Version:            data.Version,
+			Debug:              data.Flags.Debug,
+			Logf:               Logf,
+		}
+	}
+
+	if api == nil {
+		return false, nil // nothing found (display help!)
+	}
+
+	// We don't use these for the setup command in normal operation.
+	if data.Flags.Debug {
+		cliUtil.Hello(data.Program, data.Version, data.Flags) // say hello!
+		defer Logf("goodbye!")
+	}
+
+	// install the exit signal handler
+	wg := &sync.WaitGroup{}
+	defer wg.Wait()
+	exit := make(chan struct{})
+	defer close(exit)
+	wg.Add(1)
+	go func() {
+		defer cancel()
+		defer wg.Done()
+		// must have buffer for max number of signals
+		signals := make(chan os.Signal, 3+1) // 3 * ^C + 1 * SIGTERM
+		signal.Notify(signals, os.Interrupt) // catch ^C
+		//signal.Notify(signals, os.Kill) // catch signals
+		signal.Notify(signals, syscall.SIGTERM)
+		var count uint8
+		for {
+			select {
+			case sig := <-signals: // any signal will do
+				if sig != os.Interrupt {
+					data.Flags.Logf("interrupted by signal")
+					return
+				}
+
+				switch count {
+				case 0:
+					data.Flags.Logf("interrupted by ^C")
+					cancel()
+				case 1:
+					data.Flags.Logf("interrupted by ^C (fast pause)")
+					cancel()
+				case 2:
+					data.Flags.Logf("interrupted by ^C (hard interrupt)")
+					cancel()
+				}
+				count++
+
+			case <-exit:
+				return
+			}
+		}
+	}()
+
+	if err := api.Main(ctx); err != nil {
+		if data.Flags.Debug {
+			data.Flags.Logf("main: %+v", err)
+		}
+		return false, err
+	}
+
+	return true, nil
+}

cli/run.go

@@ -0,0 +1,245 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+package cli
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+
+	cliUtil "github.com/purpleidea/mgmt/cli/util"
+	"github.com/purpleidea/mgmt/gapi"
+	"github.com/purpleidea/mgmt/lib"
+	"github.com/purpleidea/mgmt/util"
+	"github.com/purpleidea/mgmt/util/errwrap"
+
+	"github.com/spf13/afero"
+)
+
+// RunArgs is the CLI parsing structure and type of the parsed result. This
+// particular one contains all the common flags for the `run` subcommand which
+// all frontends can use.
+type RunArgs struct {
+	lib.Config // embedded config (can't be a pointer) https://github.com/alexflint/go-arg/issues/240
+
+	RunEmpty      *cliUtil.EmptyArgs      `arg:"subcommand:empty" help:"run empty payload"`
+	RunLang       *cliUtil.LangArgs       `arg:"subcommand:lang" help:"run lang (mcl) payload"`
+	RunYaml       *cliUtil.YamlArgs       `arg:"subcommand:yaml" help:"run yaml graph payload"`
+	RunPuppet     *cliUtil.PuppetArgs     `arg:"subcommand:puppet" help:"run puppet graph payload"`
+	RunLangPuppet *cliUtil.LangPuppetArgs `arg:"subcommand:langpuppet" help:"run a combined lang/puppet graph payload"`
+}
+
+// Run executes the correct subcommand. It errors if there's ever an error. It
+// returns true if we did activate one of the subcommands. It returns false if
+// we did not. This information is used so that the top-level parser can return
+// usage or help information if no subcommand activates. This particular Run is
+// the run for the main `run` subcommand. This always requires a frontend to
+// start the engine, but if you don't want a graph, you can use the `empty`
+// frontend. The engine backend is agnostic to which frontend is running, in
+// fact, you can deploy with multiple different frontends, one after another, on
+// the same engine.
+func (obj *RunArgs) Run(ctx context.Context, data *cliUtil.Data) (bool, error) {
+	var name string
+	var args interface{}
+	if cmd := obj.RunEmpty; cmd != nil {
+		name = cliUtil.LookupSubcommand(obj, cmd) // "empty"
+		args = cmd
+	}
+	if cmd := obj.RunLang; cmd != nil {
+		name = cliUtil.LookupSubcommand(obj, cmd) // "lang"
+		args = cmd
+	}
+	if cmd := obj.RunYaml; cmd != nil {
+		name = cliUtil.LookupSubcommand(obj, cmd) // "yaml"
+		args = cmd
+	}
+	if cmd := obj.RunPuppet; cmd != nil {
+		name = cliUtil.LookupSubcommand(obj, cmd) // "puppet"
+		args = cmd
+	}
+	if cmd := obj.RunLangPuppet; cmd != nil {
+		name = cliUtil.LookupSubcommand(obj, cmd) // "langpuppet"
+		args = cmd
+	}
+
+	// XXX: workaround https://github.com/alexflint/go-arg/issues/239
+	lists := [][]string{
+		obj.Seeds,
+		obj.ClientURLs,
+		obj.ServerURLs,
+		obj.AdvertiseClientURLs,
+		obj.AdvertiseServerURLs,
+	}
+	gapiNames := gapi.Names() // list of registered names
+	for _, list := range lists {
+		if l := len(list); name == "" && l > 1 {
+			elem := list[l-2] // second to last element
+			if util.StrInList(elem, gapiNames) {
+				return false, cliUtil.CliParseError(cliUtil.MissingEquals) // consistent errors
+			}
+		}
+	}
+
+	fn, exists := gapi.RegisteredGAPIs[name]
+	if !exists {
+		return false, nil // did not activate
+	}
+	gapiObj := fn()
+
+	main := &lib.Main{}
+	main.Config = &obj.Config // pass in all the parsed data
+
+	main.Program, main.Version = data.Program, data.Version
+	main.Debug, main.Logf = data.Flags.Debug, data.Flags.Logf // no prefix
+	Logf := func(format string, v ...interface{}) {
+		data.Flags.Logf("main: "+format, v...)
+	}
+
+	cliUtil.Hello(main.Program, main.Version, data.Flags) // say hello!
+	defer Logf("goodbye!")
+
+	// create a memory backed temporary filesystem for storing runtime data
+	mmFs := afero.NewMemMapFs()
+	afs := &afero.Afero{Fs: mmFs} // wrap so that we're implementing ioutil
+	standaloneFs := &util.AferoFs{Afero: afs}
+	main.DeployFs = standaloneFs
+
+	info := &gapi.Info{
+		Args: args,
+		Flags: &gapi.Flags{
+			Hostname: obj.Hostname,
+			Noop:     obj.Noop,
+			Sema:     obj.Sema,
+			//Update: obj.Update,
+
+			NoAutoEdges: obj.NoAutoEdges,
+		},
+
+		Fs:    standaloneFs,
+		Debug: data.Flags.Debug,
+		Logf: func(format string, v ...interface{}) {
+			data.Flags.Logf("cli: "+format, v...)
+		},
+	}
+
+	deploy, err := gapiObj.Cli(info)
+	if err != nil {
+		return false, cliUtil.CliParseError(err) // consistent errors
+	}
+
+	if cmd := obj.RunLang; cmd != nil && cmd.OnlyUnify && deploy == nil {
+		return true, nil // we end early
+	}
+	if cmd := obj.RunLang; cmd != nil && cmd.OnlyDownload && deploy == nil {
+		return true, nil // we end early
+	}
+	main.Deploy = deploy
+	if main.Deploy == nil {
+		// nobody activated, but we'll still watch the etcd deploy chan,
+		// and if there is deployed code that's ready to run, we'll run!
+		data.Flags.Logf("main: no frontend selected (no GAPI activated)")
+	}
+
+	if err := main.Validate(); err != nil {
+		return false, err
+	}
+
+	if err := main.Init(); err != nil {
+		return false, err
+	}
+
+	// install the exit signal handler
+	wg := &sync.WaitGroup{}
+	defer wg.Wait()
+	exit := make(chan struct{})
+	defer close(exit)
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		// must have buffer for max number of signals
+		signals := make(chan os.Signal, 3+1) // 3 * ^C + 1 * SIGTERM
+		signal.Notify(signals, os.Interrupt) // catch ^C
+		//signal.Notify(signals, os.Kill) // catch signals
+		signal.Notify(signals, syscall.SIGTERM)
+		var count uint8
+		for {
+			select {
+			case sig := <-signals: // any signal will do
+				if sig != os.Interrupt {
+					data.Flags.Logf("interrupted by signal")
+					main.Interrupt(fmt.Errorf("killed by %v", sig))
+					return
+				}
+
+				switch count {
+				case 0:
+					data.Flags.Logf("interrupted by ^C")
+					main.Exit(nil)
+				case 1:
+					data.Flags.Logf("interrupted by ^C (fast pause)")
+					main.FastExit(nil)
+				case 2:
+					data.Flags.Logf("interrupted by ^C (hard interrupt)")
+					main.Interrupt(nil)
+				}
+				count++
+
+			case <-exit:
+				return
+			}
+		}
+	}()
+
+	reterr := main.Run()
+	if reterr != nil {
+		// log the error message returned
+		if data.Flags.Debug {
+			data.Flags.Logf("main: %+v", reterr)
+		}
+	}
+
+	if err := main.Close(); err != nil {
+		if data.Flags.Debug {
+			data.Flags.Logf("main: Close: %+v", err)
+		}
+		if reterr == nil {
+			return false, err
+		}
+		reterr = errwrap.Append(reterr, err)
+	}
+
+	if reterr != nil {
+		return false, reterr
+	}
+	return true, nil
+}

cli/setup.go

@@ -0,0 +1,180 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+package cli
+
+import (
+	"context"
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+
+	cliUtil "github.com/purpleidea/mgmt/cli/util"
+	"github.com/purpleidea/mgmt/setup"
+)
+
+// SetupArgs is the CLI parsing structure and type of the parsed result. This
+// particular one contains all the common flags for the `setup` subcommand.
+type SetupArgs struct {
+	setup.Config // embedded config (can't be a pointer) https://github.com/alexflint/go-arg/issues/240
+
+	SetupPkg       *cliUtil.SetupPkgArgs       `arg:"subcommand:pkg" help:"setup packages"`
+	SetupSvc       *cliUtil.SetupSvcArgs       `arg:"subcommand:svc" help:"setup services"`
+	SetupFirstboot *cliUtil.SetupFirstbootArgs `arg:"subcommand:firstboot" help:"setup firstboot"`
+}
+
+// Run executes the correct subcommand. It errors if there's ever an error. It
+// returns true if we did activate one of the subcommands. It returns false if
+// we did not. This information is used so that the top-level parser can return
+// usage or help information if no subcommand activates. This particular Run is
+// the run for the main `setup` subcommand. The setup command does some
+// bootstrap work to help get things going.
+func (obj *SetupArgs) Run(ctx context.Context, data *cliUtil.Data) (bool, error) {
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	var name string
+	var args interface{}
+	if cmd := obj.SetupPkg; cmd != nil {
+		name = cliUtil.LookupSubcommand(obj, cmd) // "pkg"
+		args = cmd
+	}
+	if cmd := obj.SetupSvc; cmd != nil {
+		name = cliUtil.LookupSubcommand(obj, cmd) // "svc"
+		args = cmd
+	}
+	if cmd := obj.SetupFirstboot; cmd != nil {
+		name = cliUtil.LookupSubcommand(obj, cmd) // "firstboot"
+		args = cmd
+	}
+	_ = name
+
+	Logf := func(format string, v ...interface{}) {
+		// Don't block this globally...
+		//if !data.Flags.Debug {
+		//	return
+		//}
+		data.Flags.Logf("main: "+format, v...)
+	}
+
+	var api setup.API
+
+	if cmd := obj.SetupPkg; cmd != nil {
+		api = &setup.Pkg{
+			SetupPkgArgs: args.(*cliUtil.SetupPkgArgs),
+			Config:       obj.Config,
+			Program:      data.Program,
+			Version:      data.Version,
+			Debug:        data.Flags.Debug,
+			Logf:         Logf,
+		}
+	}
+	if cmd := obj.SetupSvc; cmd != nil {
+		api = &setup.Svc{
+			SetupSvcArgs: args.(*cliUtil.SetupSvcArgs),
+			Config:       obj.Config,
+			Program:      data.Program,
+			Version:      data.Version,
+			Debug:        data.Flags.Debug,
+			Logf:         Logf,
+		}
+	}
+	if cmd := obj.SetupFirstboot; cmd != nil {
+		api = &setup.Firstboot{
+			SetupFirstbootArgs: args.(*cliUtil.SetupFirstbootArgs),
+			Config:             obj.Config,
+			Program:            data.Program,
+			Version:            data.Version,
+			Debug:              data.Flags.Debug,
+			Logf:               Logf,
+		}
+	}
+
+	if api == nil {
+		return false, nil // nothing found (display help!)
+	}
+
+	// We don't use these for the setup command in normal operation.
+	if data.Flags.Debug {
+		cliUtil.Hello(data.Program, data.Version, data.Flags) // say hello!
+		defer Logf("goodbye!")
+	}
+
+	// install the exit signal handler
+	wg := &sync.WaitGroup{}
+	defer wg.Wait()
+	exit := make(chan struct{})
+	defer close(exit)
+	wg.Add(1)
+	go func() {
+		defer cancel()
+		defer wg.Done()
+		// must have buffer for max number of signals
+		signals := make(chan os.Signal, 3+1) // 3 * ^C + 1 * SIGTERM
+		signal.Notify(signals, os.Interrupt) // catch ^C
+		//signal.Notify(signals, os.Kill) // catch signals
+		signal.Notify(signals, syscall.SIGTERM)
+		var count uint8
+		for {
+			select {
+			case sig := <-signals: // any signal will do
+				if sig != os.Interrupt {
+					data.Flags.Logf("interrupted by signal")
+					return
+				}
+
+				switch count {
+				case 0:
+					data.Flags.Logf("interrupted by ^C")
+					cancel()
+				case 1:
+					data.Flags.Logf("interrupted by ^C (fast pause)")
+					cancel()
+				case 2:
+					data.Flags.Logf("interrupted by ^C (hard interrupt)")
+					cancel()
+				}
+				count++
+
+			case <-exit:
+				return
+			}
+		}
+	}()
+
+	if err := api.Main(ctx); err != nil {
+		if data.Flags.Debug {
+			data.Flags.Logf("main: %+v", err)
+		}
+		return false, err
+	}
+
+	return true, nil
+}

cli/tools.go

@@ -0,0 +1,150 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+package cli
+
+import (
+	"context"
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+
+	cliUtil "github.com/purpleidea/mgmt/cli/util"
+	"github.com/purpleidea/mgmt/tools"
+)
+
+// ToolsArgs is the CLI parsing structure and type of the parsed result. This
+// particular one contains all the common flags for the `tools` subcommand.
+type ToolsArgs struct {
+	tools.Config // embedded config (can't be a pointer) https://github.com/alexflint/go-arg/issues/240
+
+	ToolsGrow *cliUtil.ToolsGrowArgs `arg:"subcommand:grow" help:"tools for growing storage"`
+}
+
+// Run executes the correct subcommand. It errors if there's ever an error. It
+// returns true if we did activate one of the subcommands. It returns false if
+// we did not. This information is used so that the top-level parser can return
+// usage or help information if no subcommand activates. This particular Run is
+// the run for the main `tools` subcommand. The tools command provides some
+// functionality which can be helpful with provisioning and config management.
+func (obj *ToolsArgs) Run(ctx context.Context, data *cliUtil.Data) (bool, error) {
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	var name string
+	var args interface{}
+	if cmd := obj.ToolsGrow; cmd != nil {
+		name = cliUtil.LookupSubcommand(obj, cmd) // "grow"
+		args = cmd
+	}
+	_ = name
+
+	Logf := func(format string, v ...interface{}) {
+		// Don't block this globally...
+		//if !data.Flags.Debug {
+		//	return
+		//}
+		data.Flags.Logf("main: "+format, v...)
+	}
+
+	var api tools.API
+
+	if cmd := obj.ToolsGrow; cmd != nil {
+		api = &tools.Grow{
+			ToolsGrowArgs: args.(*cliUtil.ToolsGrowArgs),
+			Config:        obj.Config,
+			Program:       data.Program,
+			Version:       data.Version,
+			Debug:         data.Flags.Debug,
+			Logf:          Logf,
+		}
+	}
+
+	if api == nil {
+		return false, nil // nothing found (display help!)
+	}
+
+	// We don't use these for the tools command in normal operation.
+	if data.Flags.Debug {
+		cliUtil.Hello(data.Program, data.Version, data.Flags) // say hello!
+		defer Logf("goodbye!")
+	}
+
+	// install the exit signal handler
+	wg := &sync.WaitGroup{}
+	defer wg.Wait()
+	exit := make(chan struct{})
+	defer close(exit)
+	wg.Add(1)
+	go func() {
+		defer cancel()
+		defer wg.Done()
+		// must have buffer for max number of signals
+		signals := make(chan os.Signal, 3+1) // 3 * ^C + 1 * SIGTERM
+		signal.Notify(signals, os.Interrupt) // catch ^C
+		//signal.Notify(signals, os.Kill) // catch signals
+		signal.Notify(signals, syscall.SIGTERM)
+		var count uint8
+		for {
+			select {
+			case sig := <-signals: // any signal will do
+				if sig != os.Interrupt {
+					data.Flags.Logf("interrupted by signal")
+					return
+				}
+
+				switch count {
+				case 0:
+					data.Flags.Logf("interrupted by ^C")
+					cancel()
+				case 1:
+					data.Flags.Logf("interrupted by ^C (fast pause)")
+					cancel()
+				case 2:
+					data.Flags.Logf("interrupted by ^C (hard interrupt)")
+					cancel()
+				}
+				count++
+
+			case <-exit:
+				return
+			}
+		}
+	}()
+
+	if err := api.Main(ctx); err != nil {
+		if data.Flags.Debug {
+			data.Flags.Logf("main: %+v", err)
+		}
+		return false, err
+	}
+
+	return true, nil
+}

cli/util/args.go

@@ -0,0 +1,214 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+package util
+
+import (
+	"reflect"
+	"strings"
+)
+
+// LookupSubcommand returns the name of the subcommand in the obj, of a struct.
+// This is useful for determining the name of the subcommand that was activated.
+// It returns an empty string if a specific name was not found.
+func LookupSubcommand(obj interface{}, st interface{}) string {
+	val := reflect.ValueOf(obj)
+	if val.Kind() == reflect.Ptr { // max one de-referencing
+		val = val.Elem()
+	}
+
+	v := reflect.ValueOf(st) // value of the struct
+	typ := val.Type()
+	for i := 0; i < typ.NumField(); i++ {
+		f := val.Field(i) // value of the field
+		if f.Interface() != v.Interface() {
+			continue
+		}
+
+		field := typ.Field(i)
+		alias, ok := field.Tag.Lookup("arg")
+		if !ok {
+			continue
+		}
+
+		// XXX: `arg` needs a split by comma first or fancier parsing
+		prefix := "subcommand"
+		split := strings.Split(alias, ":")
+		if len(split) != 2 || split[0] != prefix {
+			continue
+		}
+
+		return split[1] // found
+	}
+	return "" // not found
+}
+
+// EmptyArgs is the empty CLI parsing structure and type of the parsed result.
+type EmptyArgs struct {
+	Wait bool `arg:"--wait" help:"don't use any existing (stale) deploys"`
+}
+
+// LangArgs is the lang CLI parsing structure and type of the parsed result.
+type LangArgs struct {
+	// Input is the input mcl code or file path or any input specification.
+	Input string `arg:"positional,required"`
+
+	// TODO: removed (temporarily?)
+	//Stdin bool `arg:"--stdin" help:"use passthrough stdin"`
+
+	Download     bool `arg:"--download" help:"download any missing imports"`
+	OnlyDownload bool `arg:"--only-download" help:"stop after downloading any missing imports"`
+	Update       bool `arg:"--update" help:"update all dependencies to the latest versions"`
+
+	OnlyUnify          bool     `arg:"--only-unify" help:"stop after type unification"`
+	SkipUnify          bool     `arg:"--skip-unify" help:"skip type unification"`
+	UnifySolver        *string  `arg:"--unify-name" help:"pick a specific unification solver"`
+	UnifyOptimizations []string `arg:"--unify-optimizations,separate" help:"list of unification optimizations to request (experts only)"`
+
+	Depth int `arg:"--depth" default:"-1" help:"max recursion depth limit (-1 is unlimited)"`
+
+	// The default of 0 means any error is a failure by default.
+	Retry int `arg:"--depth" help:"max number of retries (-1 is unlimited)"`
+
+	ModulePath string `arg:"--module-path,env:MGMT_MODULE_PATH" help:"choose the modules path (absolute)"`
+}
+
+// YamlArgs is the yaml CLI parsing structure and type of the parsed result.
+type YamlArgs struct {
+	// Input is the input yaml code or file path or any input specification.
+	Input string `arg:"positional,required"`
+}
+
+// PuppetArgs is the puppet CLI parsing structure and type of the parsed result.
+type PuppetArgs struct {
+	// Input is the input puppet code or file path or just "agent".
+	Input string `arg:"positional,required"`
+
+	// PuppetConf is the optional path to a puppet.conf config file.
+	PuppetConf string `arg:"--puppet-conf" help:"full path to the puppet.conf file to use"`
+}
+
+// LangPuppetArgs is the langpuppet CLI parsing structure and type of the parsed
+// result.
+type LangPuppetArgs struct {
+	// LangInput is the input mcl code or file path or any input specification.
+	LangInput string `arg:"--lang,required" help:"the input parameter for the lang module"`
+
+	// PuppetInput is the input puppet code or file path or just "agent".
+	PuppetInput string `arg:"--puppet,required" help:"the input parameter for the puppet module"`
+
+	// copy-pasted from PuppetArgs
+
+	// PuppetConf is the optional path to a puppet.conf config file.
+	PuppetConf string `arg:"--puppet-conf" help:"full path to the puppet.conf file to use"`
+
+	// end PuppetArgs
+
+	// copy-pasted from LangArgs
+
+	// TODO: removed (temporarily?)
+	//Stdin bool `arg:"--stdin" help:"use passthrough stdin"`
+
+	Download     bool `arg:"--download" help:"download any missing imports"`
+	OnlyDownload bool `arg:"--only-download" help:"stop after downloading any missing imports"`
+	Update       bool `arg:"--update" help:"update all dependencies to the latest versions"`
+
+	OnlyUnify bool `arg:"--only-unify" help:"stop after type unification"`
+	SkipUnify bool `arg:"--skip-unify" help:"skip type unification"`
+
+	Depth int `arg:"--depth" default:"-1" help:"max recursion depth limit (-1 is unlimited)"`
+
+	// The default of 0 means any error is a failure by default.
+	Retry int `arg:"--depth" help:"max number of retries (-1 is unlimited)"`
+
+	ModulePath string `arg:"--module-path,env:MGMT_MODULE_PATH" help:"choose the modules path (absolute)"`
+
+	// end LangArgs
+}
+
+// SetupPkgArgs is the setup service CLI parsing structure and type of the
+// parsed result.
+type SetupPkgArgs struct {
+	Distro string `arg:"--distro" help:"build for this distro"`
+	Sudo   bool   `arg:"--sudo" help:"include sudo in the command"`
+	Exec   bool   `arg:"--exec" help:"actually run these commands"`
+}
+
+// SetupSvcArgs is the setup service CLI parsing structure and type of the
+// parsed result.
+type SetupSvcArgs struct {
+	BinaryPath string `arg:"--binary-path" help:"path to the binary"`
+	SSHURL     string `arg:"--ssh-url" help:"transport the etcd client connection over SSH to this server"`
+	SSHHostKey string `arg:"--ssh-hostkey" help:"use this ssh known hosts key when connecting over SSH"`
+
+	Seeds    []string `arg:"--seeds,separate,env:MGMT_SEEDS" help:"default etcd client endpoints"`
+	NoServer bool     `arg:"--no-server" help:"do not start embedded etcd server (do not promote from client to peer)"`
+
+	Install bool `arg:"--install" help:"install the systemd mgmt service"`
+	Start   bool `arg:"--start" help:"start the mgmt service"`
+	Enable  bool `arg:"--enable" help:"enable the mgmt service"`
+}
+
+// SetupFirstbootArgs is the setup service CLI parsing structure and type of the
+// parsed result.
+type SetupFirstbootArgs struct {
+	BinaryPath string `arg:"--binary-path" help:"path to the binary"`
+	Mkdir      bool   `arg:"--mkdir" help:"make the necessary firstboot dirs"`
+	Install    bool   `arg:"--install" help:"install the systemd firstboot service"`
+	Start      bool   `arg:"--start" help:"start the firstboot service (typically not used)"`
+	Enable     bool   `arg:"--enable" help:"enable the firstboot service"`
+
+	FirstbootStartArgs // Include these options if we want to specify them.
+}
+
+// FirstbootStartArgs is the firstboot service CLI parsing structure and type of
+// the parsed result.
+type FirstbootStartArgs struct {
+	LockFilePath string `arg:"--lock-file-path" help:"path to the lock file"`
+	ScriptsDir   string `arg:"--scripts-dir" help:"path to the scripts dir"`
+	DoneDir      string `arg:"--done-dir" help:"dir to move done scripts to"`
+	LoggingDir   string `arg:"--logging-dir" help:"directory to store logs in"`
+}
+
+// DocsGenerateArgs is the docgen utility CLI parsing structure and type of the
+// parsed result.
+type DocsGenerateArgs struct {
+	Output      string `arg:"--output" help:"output path to write to"`
+	RootDir     string `arg:"--root-dir" help:"path to mgmt source dir"`
+	NoResources bool   `arg:"--no-resources" help:"skip resource doc generation"`
+	NoFunctions bool   `arg:"--no-functions" help:"skip function doc generation"`
+}
+
+// ToolsGrowArgs is the util tool CLI parsing structure and type of the parsed
+// result.
+type ToolsGrowArgs struct {
+	Mount string `arg:"--mount,required" help:"root mount point to start with"`
+	Exec  bool   `arg:"--exec" help:"actually run these commands"`
+	Done  string `arg:"--done" help:"create this file when done, skip if it exists"`
+}

cli/util/hello.go

@@ -0,0 +1,47 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+package util
+
+import (
+	"fmt"
+	"time"
+)
+
+// Hello is a simple helper function to print a hello message and time.
+func Hello(program, version string, flags Flags) {
+	var start = time.Now().UnixNano()
+	if program == "" {
+		program = "<unknown>"
+	}
+	fmt.Println(fmt.Sprintf("This is: %s, version: %s", program, version))
+	fmt.Println("Copyright (C) James Shubin and the project contributors")
+	fmt.Println("Written by James Shubin <james@shubin.ca> and the project contributors")
+	flags.Logf("main: start: %v", start)
+}

cli/util/util.go

@@ -0,0 +1,98 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+// Package util has some CLI related utility code.
+package util
+
+import (
+	"log"
+	"os"
+	"strings"
+
+	"github.com/purpleidea/mgmt/util/errwrap"
+)
+
+// Error is a constant error type that implements error.
+type Error string
+
+// Error fulfills the error interface of this type.
+func (e Error) Error() string { return string(e) }
+
+const (
+	// MissingEquals means we probably hit the parsing bug.
+	// XXX: see: https://github.com/alexflint/go-arg/issues/239
+	MissingEquals = Error("missing equals sign for list element")
+)
+
+// CliParseError returns a consistent error if we have a CLI parsing issue.
+func CliParseError(err error) error {
+	return errwrap.Wrapf(err, "cli parse error")
+}
+
+// Flags are some constant flags which are used throughout the program.
+type Flags struct {
+	Debug bool // add additional log messages
+	Logf  func(format string, v ...interface{})
+}
+
+// Data is a struct of values that we usually pass to the main CLI function.
+type Data struct {
+	Program string
+	Version string
+	Copying string
+	Tagline string
+	Flags   Flags
+	Args    []string // os.Args usually
+}
+
+// SafeProgram returns the correct program string when given a buggy variant.
+func SafeProgram(program string) string {
+	// FIXME: in sub commands, the cli package appends a space and the sub
+	// command name at the end. hack around this by only using the first bit
+	// see: https://github.com/urfave/cli/issues/783 for more details...
+	split := strings.Split(program, " ")
+	program = split[0]
+	//if program == "" {
+	//	program = "<unknown>"
+	//}
+	return program
+}
+
+// LogSetup changes some of the core logger package settings.
+func LogSetup(debug bool) {
+	// TODO: Move these log package initialization steps to the top main.go?
+	logFlags := log.LstdFlags
+	if debug {
+		logFlags = logFlags + log.Lshortfile
+	}
+	logFlags = logFlags - log.Ldate // remove the date for now
+	log.SetFlags(logFlags)
+
+	log.SetOutput(os.Stderr)
+}

converger/converger.go

@@ -1,153 +1,322 @@
 // Mgmt
-// Copyright (C) 2013-2016+ James Shubin and the project contributors
+// Copyright (C) James Shubin and the project contributors
 // Written by James Shubin <james@shubin.ca> and the project contributors
 //
 // This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Affero General Public License as published by
+// it under the terms of the GNU General Public License as published by
 // the Free Software Foundation, either version 3 of the License, or
 // (at your option) any later version.
 //
 // This program is distributed in the hope that it will be useful,
 // but WITHOUT ANY WARRANTY; without even the implied warranty of
 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU Affero General Public License for more details.
+// GNU General Public License for more details.
 //
-// You should have received a copy of the GNU Affero General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
 
 // Package converger is a facility for reporting the converged state.
 package converger
 
 import (
 	"fmt"
+	"sort"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/purpleidea/mgmt/util"
+	"github.com/purpleidea/mgmt/util/errwrap"
 )
 
-// TODO: we could make a new function that masks out the state of certain
-// UID's, but at the moment the new Timer code has obsoleted the need...
-
-// Converger is the general interface for implementing a convergence watcher
-type Converger interface { // TODO: need a better name
-	Register() ConvergerUID
-	IsConverged(ConvergerUID) bool         // is the UID converged ?
-	SetConverged(ConvergerUID, bool) error // set the converged state of the UID
-	Unregister(ConvergerUID)
-	Start()
-	Pause()
-	Loop(bool)
-	ConvergedTimer(ConvergerUID) <-chan time.Time
-	Status() map[uint64]bool
-	Timeout() int                // returns the timeout that this was created with
-	SetStateFn(func(bool) error) // sets the stateFn
-}
-
-// ConvergerUID is the interface resources can use to notify with if converged
-// you'll need to use part of the Converger interface to Register initially too
-type ConvergerUID interface {
-	ID() uint64   // get Id
-	Name() string // get a friendly name
-	SetName(string)
-	IsValid() bool // has Id been initialized ?
-	InvalidateID() // set Id to nil
-	IsConverged() bool
-	SetConverged(bool) error
-	Unregister()
-	ConvergedTimer() <-chan time.Time
-	StartTimer() (func() error, error) // cancellable is the same as StopTimer()
-	ResetTimer() error                 // resets counter to zero
-	StopTimer() error
-}
-
-// converger is an implementation of the Converger interface
-type converger struct {
-	timeout   int              // must be zero (instant) or greater seconds to run
-	stateFn   func(bool) error // run on converged state changes with state bool
-	converged bool             // did we converge (state changes of this run Fn)
-	channel   chan struct{}    // signal here to run an isConverged check
-	control   chan bool        // control channel for start/pause
-	mutex     sync.RWMutex     // used for controlling access to status and lastid
-	lastid    uint64
-	status    map[uint64]bool
-}
-
-// convergerUID is an implementation of the ConvergerUID interface
-type convergerUID struct {
-	converger Converger
-	id        uint64
-	name      string // user defined, friendly name
-	mutex     sync.Mutex
-	timer     chan struct{}
-	running   bool // is the above timer running?
-}
-
-// NewConverger builds a new converger struct
-func NewConverger(timeout int, stateFn func(bool) error) *converger {
-	return &converger{
+// New builds a new converger coordinator.
+func New(timeout int) *Coordinator {
+	return &Coordinator{
 		timeout: timeout,
-		stateFn: stateFn,
-		channel: make(chan struct{}),
-		control: make(chan bool),
-		lastid:  0,
-		status:  make(map[uint64]bool),
+
+		mutex: &sync.RWMutex{},
+
+		//lastid: 0,
+		status: make(map[*UID]struct{}),
+
+		//converged: false, // initial state
+
+		pokeChan: make(chan struct{}, 1), // must be buffered
+
+		readyChan: make(chan struct{}), // ready signal
+
+		//paused: false, // starts off as started
+		pauseSignal: make(chan struct{}),
+		//resumeSignal: make(chan struct{}), // happens on pause
+		//pausedAck: util.NewEasyAck(), // happens on pause
+
+		sendSignal: make(chan bool),
+
+		stateFns: make(map[string]func(bool) error),
+		smutex:   &sync.RWMutex{},
+
+		closeChan: make(chan struct{}),
+		wg:        &sync.WaitGroup{},
 	}
 }
 
-// Register assigns a ConvergerUID to the caller
-func (obj *converger) Register() ConvergerUID {
+// Coordinator is the central converger engine.
+type Coordinator struct {
+	// timeout must be zero (instant) or greater seconds to run. If it's -1
+	// then this is disabled, and we never run stateFns.
+	timeout int
+
+	// mutex is used for controlling access to status and lastid.
+	mutex *sync.RWMutex
+
+	// lastid contains the last uid we used for registration.
+	//lastid    uint64
+	// status contains a reference to each active UID.
+	status map[*UID]struct{}
+
+	// converged stores the last convergence state. When this changes, we
+	// run the stateFns.
+	converged bool
+
+	// pokeChan receives a message every time we might need to re-calculate.
+	pokeChan chan struct{}
+
+	// readyChan closes to notify any interested parties that the main loop
+	// is running.
+	readyChan chan struct{}
+
+	// paused represents if this coordinator is paused or not.
+	paused bool
+	// pauseSignal closes to request a pause of this coordinator.
+	pauseSignal chan struct{}
+	// resumeSignal closes to request a resume of this coordinator.
+	resumeSignal chan struct{}
+	// pausedAck is used to send an ack message saying that we've paused.
+	pausedAck *util.EasyAck
+
+	sendSignal chan bool // send pause (false) or resume (true)
+
+	// stateFns run on converged state changes.
+	stateFns map[string]func(bool) error
+	// smutex is used for controlling access to the stateFns map.
+	smutex *sync.RWMutex
+
+	// closeChan closes when we've been requested to shutdown.
+	closeChan chan struct{}
+	// wg waits for everything to finish.
+	wg *sync.WaitGroup
+}
+
+// Register creates a new UID which can be used to report converged state. You
+// must Unregister each UID before Shutdown will be able to finish running.
+func (obj *Coordinator) Register() *UID {
+	obj.wg.Add(1) // additional tracking for each UID
 	obj.mutex.Lock()
 	defer obj.mutex.Unlock()
-	obj.lastid++
-	obj.status[obj.lastid] = false // initialize as not converged
-	return &convergerUID{
-		converger: obj,
-		id:        obj.lastid,
-		name:      fmt.Sprintf("%d", obj.lastid), // some default
-		timer:     nil,
-		running:   false,
+	//obj.lastid++
+	uid := &UID{
+		timeout: obj.timeout, // copy the timeout here
+		//id: obj.lastid,
+		//name: fmt.Sprintf("%d", obj.lastid), // some default
+
+		isConverged: &atomic.Bool{},
+
+		poke: obj.poke,
+
+		// timer
+		mutex:   &sync.Mutex{},
+		timer:   nil,
+		running: false,
+		wg:      &sync.WaitGroup{},
 	}
+	uid.unregister = func() { obj.Unregister(uid) } // add unregister func
+	obj.status[uid] = struct{}{}                    // TODO: add converged state here?
+	return uid
 }
 
-// IsConverged gets the converged status of a uid
-func (obj *converger) IsConverged(uid ConvergerUID) bool {
-	if !uid.IsValid() {
-		panic(fmt.Sprintf("Id of ConvergerUID(%s) is nil!", uid.Name()))
-	}
-	obj.mutex.RLock()
-	isConverged, found := obj.status[uid.ID()] // lookup
-	obj.mutex.RUnlock()
-	if !found {
-		panic("Id of ConvergerUID is unregistered!")
-	}
-	return isConverged
-}
-
-// SetConverged updates the converger with the converged state of the UID
-func (obj *converger) SetConverged(uid ConvergerUID, isConverged bool) error {
-	if !uid.IsValid() {
-		return fmt.Errorf("Id of ConvergerUID(%s) is nil!", uid.Name())
-	}
+// Unregister removes the UID from the converger coordinator. If you supply an
+// invalid or unregistered uid to this function, it will panic. An unregistered
+// UID is no longer part of the convergence checking.
+func (obj *Coordinator) Unregister(uid *UID) {
+	defer obj.wg.Done() // additional tracking for each UID
 	obj.mutex.Lock()
-	if _, found := obj.status[uid.ID()]; !found {
-		panic("Id of ConvergerUID is unregistered!")
+	defer obj.mutex.Unlock()
+
+	if _, exists := obj.status[uid]; !exists {
+		panic("uid is not registered")
 	}
-	obj.status[uid.ID()] = isConverged // set
-	obj.mutex.Unlock()                 // unlock *before* poke or deadlock!
-	if isConverged != obj.converged {  // only poke if it would be helpful
-		// run in a go routine so that we never block... just queue up!
-		// this allows us to send events, even if we haven't started...
-		go func() { obj.channel <- struct{}{} }()
+	uid.StopTimer() // ignore any errors
+	delete(obj.status, uid)
+}
+
+// Run starts the main loop for the converger coordinator. It is commonly run
+// from a go routine. It blocks until the Shutdown method is run to close it.
+// NOTE: when we have very short timeouts, if we start before all the resources
+// have joined the map, then it might appear as if we converged before we did!
+func (obj *Coordinator) Run(startPaused bool) {
+	obj.wg.Add(1)
+	wg := &sync.WaitGroup{} // needed for the startPaused
+	defer wg.Wait()         // don't leave any leftover go routines running
+	if startPaused {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			obj.Pause() // ignore any errors
+			close(obj.readyChan)
+		}()
+	} else {
+		close(obj.readyChan) // we must wait till the wg.Add(1) has happened...
 	}
+	defer obj.wg.Done()
+	for {
+		// pause if one was requested...
+		select {
+		//case <-obj.pauseSignal: // channel closes
+		//	obj.pausedAck.Ack() // send ack
+		//	// we are paused now, and waiting for resume or exit...
+		//	select {
+		//	case <-obj.resumeSignal: // channel closes # XXX: RACE READ
+		//		// resumed!
+		//
+		//	case <-obj.closeChan: // we can always escape
+		//		return
+		//	}
+		case b, _ := <-obj.sendSignal:
+			if b { // resume
+				panic("unexpected resume") // TODO: continue instead?
+			}
+			// paused
+			obj.pausedAck.Ack() // send ack
+			// we are paused now, and waiting for resume or exit...
+			select {
+			case b, _ := <-obj.sendSignal:
+				if !b { // pause
+					panic("unexpected pause") // TODO: continue instead?
+				}
+				// resumed!
+
+			case <-obj.closeChan: // we can always escape
+				return
+			}
+
+		case _, ok := <-obj.pokeChan: // we got an event (re-calculate)
+			if !ok {
+				return
+			}
+
+			if err := obj.test(); err != nil {
+				// FIXME: what to do on error ?
+			}
+
+		case <-obj.closeChan: // we can always escape
+			return
+		}
+	}
+}
+
+// Ready blocks until the Run loop has started up. This is useful so that we
+// don't run Shutdown before we've even started up properly.
+func (obj *Coordinator) Ready() {
+	select {
+	case <-obj.readyChan:
+	}
+}
+
+// Shutdown sends a signal to the Run loop that it should exit. This blocks
+// until it does.
+func (obj *Coordinator) Shutdown() {
+	close(obj.closeChan)
+	obj.wg.Wait()
+	close(obj.pokeChan) // free memory?
+}
+
+// Pause pauses the coordinator. It should not be called on an already paused
+// coordinator. It will block until the coordinator pauses with an
+// acknowledgment, or until an exit is requested. If the latter happens it will
+// error. It is NOT thread-safe with the Resume() method so only call either one
+// at a time.
+func (obj *Coordinator) Pause() error {
+	if obj.paused {
+		return fmt.Errorf("already paused")
+	}
+
+	obj.pausedAck = util.NewEasyAck()
+	//obj.resumeSignal = make(chan struct{}) // build the resume signal XXX: RACE WRITE
+	//close(obj.pauseSignal)
+	select {
+	case obj.sendSignal <- false:
+	case <-obj.closeChan:
+		return fmt.Errorf("closing")
+	}
+
+	// wait for ack (or exit signal)
+	select {
+	case <-obj.pausedAck.Wait(): // we got it!
+		// we're paused
+	case <-obj.closeChan:
+		return fmt.Errorf("closing")
+	}
+	obj.paused = true
+
 	return nil
 }
 
-// isConverged returns true if *every* registered uid has converged
-func (obj *converger) isConverged() bool {
-	obj.mutex.RLock() // take a read lock
-	defer obj.mutex.RUnlock()
-	for _, v := range obj.status {
+// Resume unpauses the coordinator. It can be safely called on a brand-new
+// coordinator that has just started running without incident. It is NOT
+// thread-safe with the Pause() method, so only call either one at a time.
+func (obj *Coordinator) Resume() {
+	// TODO: do we need a mutex around Resume?
+	if !obj.paused { // no need to unpause brand-new resources
+		return
+	}
+
+	//obj.pauseSignal = make(chan struct{}) // rebuild for next pause
+	//close(obj.resumeSignal)
+	select {
+	case obj.sendSignal <- true:
+	case <-obj.closeChan:
+		return
+	}
+
+	obj.poke() // unblock and notice the resume if necessary
+
+	obj.paused = false
+
+	// no need to wait for it to resume
+	//return // implied
+}
+
+// poke sends a message to the coordinator telling it that it should re-evaluate
+// whether we're converged or not. This does not block. Do not run this in a
+// goroutine. It must not be called after Shutdown has been called.
+func (obj *Coordinator) poke() {
+	// redundant
+	//if len(obj.pokeChan) > 0 {
+	//	return
+	//}
+
+	select {
+	case obj.pokeChan <- struct{}{}:
+	default: // if chan is now full because more than one poke happened...
+	}
+}
+
+// IsConverged returns true if *every* registered uid has converged. If there
+// are no registered UID's, then this will return true.
+func (obj *Coordinator) IsConverged() bool {
+	for _, v := range obj.Status() {
 		if !v { // everyone must be converged for this to be true
 			return false
 		}
@@ -155,192 +324,170 @@ func (obj *converger) isConverged() bool {
 	return true
 }
 
-// Unregister dissociates the ConvergedUID from the converged checking
-func (obj *converger) Unregister(uid ConvergerUID) {
-	if !uid.IsValid() {
-		panic(fmt.Sprintf("Id of ConvergerUID(%s) is nil!", uid.Name()))
+// test evaluates whether we're converged or not and runs the state change. It
+// is NOT thread-safe.
+func (obj *Coordinator) test() error {
+	// TODO: add these checks elsewhere to prevent anything from running?
+	if obj.timeout < 0 {
+		return nil // nothing to do (only run if timeout is valid)
 	}
-	obj.mutex.Lock()
-	uid.StopTimer() // ignore any errors
-	delete(obj.status, uid.ID())
-	obj.mutex.Unlock()
-	uid.InvalidateID()
-}
 
-// Start causes a Converger object to start or resume running
-func (obj *converger) Start() {
-	obj.control <- true
-}
+	converged := obj.IsConverged()
+	defer func() {
+		obj.converged = converged // set this only at the end...
+	}()
 
-// Pause causes a Converger object to stop running temporarily
-func (obj *converger) Pause() { // FIXME: add a sync ACK on pause before return
-	obj.control <- false
-}
-
-// Loop is the main loop for a Converger object; it usually runs in a goroutine
-// TODO: we could eventually have each resource tell us as soon as it converges
-// and then keep track of the time delays here, to avoid callers needing select
-// NOTE: when we have very short timeouts, if we start before all the resources
-// have joined the map, then it might appears as if we converged before we did!
-func (obj *converger) Loop(startPaused bool) {
-	if obj.control == nil {
-		panic("Converger not initialized correctly")
-	}
-	if startPaused { // start paused without racing
-		select {
-		case e := <-obj.control:
-			if !e {
-				panic("Converger expected true!")
-			}
+	if !converged {
+		if !obj.converged { // were we previously also not converged?
+			return nil // nothing to do
 		}
-	}
-	for {
-		select {
-		case e := <-obj.control: // expecting "false" which means pause!
-			if e {
-				panic("Converger expected false!")
-			}
-			// now i'm paused...
-			select {
-			case e := <-obj.control:
-				if !e {
-					panic("Converger expected true!")
-				}
-				// restart
-				// kick once to refresh the check...
-				go func() { obj.channel <- struct{}{} }()
-				continue
-			}
 
-		case <-obj.channel:
-			if !obj.isConverged() {
-				if obj.converged { // we're doing a state change
-					if obj.stateFn != nil {
-						// call an arbitrary function
-						if err := obj.stateFn(false); err != nil {
-							// FIXME: what to do on error ?
-						}
-					}
-				}
-				obj.converged = false
-				continue
-			}
-
-			// we have converged!
-			if obj.timeout >= 0 { // only run if timeout is valid
-				if !obj.converged { // we're doing a state change
-					if obj.stateFn != nil {
-						// call an arbitrary function
-						if err := obj.stateFn(true); err != nil {
-							// FIXME: what to do on error ?
-						}
-					}
-				}
-			}
-			obj.converged = true
-			// loop and wait again...
-		}
+		// we're doing a state change
+		// call the arbitrary functions (takes a read lock!)
+		return obj.runStateFns(false)
 	}
+
+	// we have converged!
+	if obj.converged { // were we previously also converged?
+		return nil // nothing to do
+	}
+
+	// call the arbitrary functions (takes a read lock!)
+	return obj.runStateFns(true)
 }
 
-// ConvergedTimer adds a timeout to a select call and blocks until then
-// TODO: this means we could eventually have per resource converged timeouts
-func (obj *converger) ConvergedTimer(uid ConvergerUID) <-chan time.Time {
-	// be clever: if i'm already converged, this timeout should block which
-	// avoids unnecessary new signals being sent! this avoids fast loops if
-	// we have a low timeout, or in particular a timeout == 0
-	if uid.IsConverged() {
-		// blocks the case statement in select forever!
-		return util.TimeAfterOrBlock(-1)
+// runStateFns runs the list of stored state functions.
+func (obj *Coordinator) runStateFns(converged bool) error {
+	obj.smutex.RLock()
+	defer obj.smutex.RUnlock()
+	var keys []string
+	for k := range obj.stateFns {
+		keys = append(keys, k)
 	}
-	return util.TimeAfterOrBlock(obj.timeout)
+	sort.Strings(keys)
+	var err error
+	for _, name := range keys { // run in deterministic order
+		fn := obj.stateFns[name]
+		// call an arbitrary function
+		e := fn(converged)
+		err = errwrap.Append(err, e) // list of errors
+	}
+	return err
+}
+
+// AddStateFn adds a state function to be run on change of converged state.
+func (obj *Coordinator) AddStateFn(name string, stateFn func(bool) error) error {
+	obj.smutex.Lock()
+	defer obj.smutex.Unlock()
+	if _, exists := obj.stateFns[name]; exists {
+		return fmt.Errorf("a stateFn with that name already exists")
+	}
+	obj.stateFns[name] = stateFn
+	return nil
+}
+
+// RemoveStateFn removes a state function from running on change of converged
+// state.
+func (obj *Coordinator) RemoveStateFn(name string) error {
+	obj.smutex.Lock()
+	defer obj.smutex.Unlock()
+	if _, exists := obj.stateFns[name]; !exists {
+		return fmt.Errorf("a stateFn with that name doesn't exist")
+	}
+	delete(obj.stateFns, name)
+	return nil
 }
 
 // Status returns a map of the converged status of each UID.
-func (obj *converger) Status() map[uint64]bool {
-	status := make(map[uint64]bool)
+func (obj *Coordinator) Status() map[*UID]bool {
+	status := make(map[*UID]bool)
 	obj.mutex.RLock() // take a read lock
 	defer obj.mutex.RUnlock()
-	for k, v := range obj.status { // make a copy to avoid the mutex
-		status[k] = v
+	for k := range obj.status {
+		status[k] = k.IsConverged()
 	}
 	return status
 }
 
 // Timeout returns the timeout in seconds that converger was created with. This
 // is useful to avoid passing in the timeout value separately when you're
-// already passing in the Converger struct.
-func (obj *converger) Timeout() int {
+// already passing in the Coordinator struct.
+func (obj *Coordinator) Timeout() int {
 	return obj.timeout
 }
 
-// SetStateFn sets the state function to be run on change of converged state.
-func (obj *converger) SetStateFn(stateFn func(bool) error) {
-	obj.stateFn = stateFn
+// UID represents one of the probes for the converger coordinator. It is created
+// by calling the Register method of the Coordinator struct. It should be freed
+// after use with Unregister.
+type UID struct {
+	// timeout is a copy of the main timeout. It could eventually be used
+	// for per-UID timeouts too.
+	timeout int
+	// isConverged stores the convergence state of this particular UID.
+	isConverged *atomic.Bool
+
+	// poke stores a reference to the main poke function.
+	poke func()
+	// unregister stores a reference to the unregister function.
+	unregister func()
+
+	// timer
+	mutex   *sync.Mutex
+	timer   chan struct{}
+	running bool // is the timer running?
+	wg      *sync.WaitGroup
 }
 
-// Id returns the unique id of this UID object
-func (obj *convergerUID) ID() uint64 {
-	return obj.id
+// Unregister removes this UID from the converger coordinator. An unregistered
+// UID is no longer part of the convergence checking.
+func (obj *UID) Unregister() {
+	obj.unregister()
 }
 
-// Name returns a user defined name for the specific convergerUID.
-func (obj *convergerUID) Name() string {
-	return obj.name
+// IsConverged reports whether this UID is converged or not.
+func (obj *UID) IsConverged() bool {
+	return obj.isConverged.Load()
 }
 
-// SetName sets a user defined name for the specific convergerUID.
-func (obj *convergerUID) SetName(name string) {
-	obj.name = name
+// SetConverged sets the convergence state of this UID. This is used by the
+// running timer if one is started. The timer will overwrite any value set by
+// this method.
+func (obj *UID) SetConverged(isConverged bool) {
+	obj.isConverged.Store(isConverged)
+	obj.poke() // notify of change
 }
 
-// IsValid tells us if the id is valid or has already been destroyed
-func (obj *convergerUID) IsValid() bool {
-	return obj.id != 0 // an id of 0 is invalid
-}
-
-// InvalidateID marks the id as no longer valid
-func (obj *convergerUID) InvalidateID() {
-	obj.id = 0 // an id of 0 is invalid
-}
-
-// IsConverged is a helper function to the regular IsConverged method
-func (obj *convergerUID) IsConverged() bool {
-	return obj.converger.IsConverged(obj)
-}
-
-// SetConverged is a helper function to the regular SetConverged notification
-func (obj *convergerUID) SetConverged(isConverged bool) error {
-	return obj.converger.SetConverged(obj, isConverged)
-}
-
-// Unregister is a helper function to unregister myself
-func (obj *convergerUID) Unregister() {
-	obj.converger.Unregister(obj)
-}
-
-// ConvergedTimer is a helper around the regular ConvergedTimer method
-func (obj *convergerUID) ConvergedTimer() <-chan time.Time {
-	return obj.converger.ConvergedTimer(obj)
-}
-
-// StartTimer runs an invisible timer that automatically converges on timeout.
-func (obj *convergerUID) StartTimer() (func() error, error) {
-	obj.mutex.Lock()
-	if !obj.running {
-		obj.timer = make(chan struct{})
-		obj.running = true
-	} else {
-		obj.mutex.Unlock()
-		return obj.StopTimer, fmt.Errorf("Timer already started!")
+// ConvergedTimer adds a timeout to a select call and blocks until then.
+// TODO: this means we could eventually have per resource converged timeouts
+func (obj *UID) ConvergedTimer() <-chan time.Time {
+	// be clever: if i'm already converged, this timeout should block which
+	// avoids unnecessary new signals being sent! this avoids fast loops if
+	// we have a low timeout, or in particular a timeout == 0
+	if obj.IsConverged() {
+		// blocks the case statement in select forever!
+		return util.TimeAfterOrBlock(-1)
 	}
-	obj.mutex.Unlock()
+	return util.TimeAfterOrBlock(int(obj.timeout))
+}
+
+// StartTimer runs a timer that sets us as converged on timeout. It also returns
+// a handle to the StopTimer function which should be run before exit.
+func (obj *UID) StartTimer() (func() error, error) {
+	obj.mutex.Lock()
+	defer obj.mutex.Unlock()
+	if obj.running {
+		return obj.StopTimer, fmt.Errorf("timer already started")
+	}
+	obj.timer = make(chan struct{})
+	obj.running = true
+	obj.wg.Add(1)
 	go func() {
+		defer obj.wg.Done()
 		for {
 			select {
 			case _, ok := <-obj.timer: // reset signal channel
-				if !ok { // channel is closed
-					return // false to exit
+				if !ok {
+					return
 				}
 				obj.SetConverged(false)
 
@@ -348,8 +495,8 @@ func (obj *convergerUID) StartTimer() (func() error, error) {
 				obj.SetConverged(true) // converged!
 				select {
 				case _, ok := <-obj.timer: // reset signal channel
-					if !ok { // channel is closed
-						return // false to exit
+					if !ok {
+						return
 					}
 				}
 			}
@@ -358,25 +505,26 @@ func (obj *convergerUID) StartTimer() (func() error, error) {
 	return obj.StopTimer, nil
 }
 
-// ResetTimer resets the counter to zero if using a StartTimer internally.
-func (obj *convergerUID) ResetTimer() error {
+// ResetTimer resets the timer to zero.
+func (obj *UID) ResetTimer() error {
 	obj.mutex.Lock()
 	defer obj.mutex.Unlock()
 	if obj.running {
 		obj.timer <- struct{}{} // send the reset message
 		return nil
 	}
-	return fmt.Errorf("Timer hasn't been started!")
+	return fmt.Errorf("timer hasn't been started")
 }
 
-// StopTimer stops the running timer permanently until a StartTimer is run.
-func (obj *convergerUID) StopTimer() error {
+// StopTimer stops the running timer.
+func (obj *UID) StopTimer() error {
 	obj.mutex.Lock()
 	defer obj.mutex.Unlock()
 	if !obj.running {
-		return fmt.Errorf("Timer isn't running!")
+		return fmt.Errorf("timer isn't running")
 	}
 	close(obj.timer)
+	obj.wg.Wait()
 	obj.running = false
 	return nil
 }

converger/converger_test.go

@@ -0,0 +1,43 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+//go:build !root
+
+package converger
+
+import (
+	"testing"
+)
+
+func TestBufferedChan1(t *testing.T) {
+	ch := make(chan bool, 1)
+	ch <- true
+	close(ch) // closing a channel that's not empty should not block
+	// must be able to exit without blocking anywhere
+}

debian/.gitignore

@@ -0,0 +1,7 @@
+*.debhelper.log
+*debhelper
+changelog
+debhelper-build-stamp
+files
+mgmt.substvars
+mgmt/*

debian/compat

@@ -0,0 +1 @@
+9

debian/control

@@ -0,0 +1,17 @@
+Source: mgmt
+Maintainer: Johan Bloemberg (aequitas) <mgmt@ijohan.nl>
+Build-Depends:
+               debhelper,
+               devscripts,
+               dh-golang,
+               dh-systemd,
+               golang-go,
+
+Package: mgmt
+Architecture: any
+Depends: ${shlibs:Depends}, ${misc:Depends}, packagekit
+Suggests:      graphviz
+Description: mgmt: next generation config management!
+ The mgmt tool is a next generation config management solution. It's
+ ready for production, and we hope you try out the future soon. Get
+ involved today!

debian/copyright

@@ -0,0 +1,33 @@
+Format: http://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+Upstream-Name: mgmt
+Source: <https://github.com/purpleidea/mgmt>
+
+Files: *
+Copyright: Copyright (C) James Shubin and the project contributors
+License: GPL-3.0
+
+License: GPL-3.0
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+  Additional permission under GNU GPL version 3 section 7
+
+  If you modify this program, or any covered work, by linking or combining it
+  with embedded mcl code and modules (and that the embedded mcl code and
+  modules which link with this program, contain a copy of their source code in
+  the authoritative form) containing parts covered by the terms of any other
+  license, the licensors of this program grant you additional permission to
+  convey the resulting work. Furthermore, the licensors of this program grant
+  the original author, James Shubin, additional permission to update this
+  additional permission if he deems it necessary to achieve the goals of this
+  additional permission.

debian/mgmt.docs

@@ -0,0 +1,11 @@
+AUTHORS
+COPYING
+COPYRIGHT
+README.md
+THANKS
+TODO.md
+docs
+examples
+misc/bashrc.sh
+misc/delta-cpu.sh
+misc/mgmt.service

debian/mgmt.install

@@ -0,0 +1,2 @@
+mgmt usr/bin
+misc/mgmt.service /lib/systemd/system

debian/rules

@@ -0,0 +1,15 @@
+#!/usr/bin/make -f
+
+export DH_OPTIONS
+export DH_GOPKG := mgmt
+export DH_GOLANG_INSTALL_ALL := 1
+unexport GOROOT
+
+override_dh_auto_build:
+	make build
+
+override_dh_auto_test:
+	@echo "Tests are disabled for now"
+
+%:
+	dh $@ --with=systemd

doc.go

@@ -1,19 +1,31 @@
 // Mgmt
-// Copyright (C) 2013-2016+ James Shubin and the project contributors
+// Copyright (C) James Shubin and the project contributors
 // Written by James Shubin <james@shubin.ca> and the project contributors
 //
 // This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Affero General Public License as published by
+// it under the terms of the GNU General Public License as published by
 // the Free Software Foundation, either version 3 of the License, or
 // (at your option) any later version.
 //
 // This program is distributed in the hope that it will be useful,
 // but WITHOUT ANY WARRANTY; without even the implied warranty of
 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU Affero General Public License for more details.
+// GNU General Public License for more details.
 //
-// You should have received a copy of the GNU Affero General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
 
 // Package main provides the main entrypoint for using the `mgmt` software.
 package main

docker/Dockerfile

@@ -1,10 +1,10 @@
-FROM golang:1.6.2
+FROM golang:1.23
 
 MAINTAINER Michał Czeraszkiewicz <contact@czerasz.com>
 
 # Set the reset cache variable
 # Read more here: http://czerasz.com/2014/11/13/docker-tip-and-tricks/#use-refreshedat-variable-for-better-cache-control
-ENV REFRESHED_AT 2016-05-10
+ENV REFRESHED_AT 2020-09-23
 
 # Update the package list to be able to use required packages
 RUN apt-get update

docker/Dockerfile-fedora.build

@@ -0,0 +1,20 @@
+FROM fedora:41
+LABEL org.opencontainers.image.authors="laurent.indermuehle@pm.me"
+
+ENV GOPATH=/root/gopath
+ENV PATH=/root/gopath/bin:/usr/local/sbin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/go/bin:/usr/local/bin
+ENV LD_LIBRARY_PATH=/usr/lib64
+ENV PKG_CONFIG_PATH=/usr/lib64/pkgconfig
+
+# This forces make-deps.sh to install Ragel 6.1 instead of 7.0
+ENV DOCKER=true
+
+RUN dnf -y install wget unzip git make which gcc gcc-c++ ruby golang
+
+RUN mkdir -p $GOPATH/src/github.com/purpleidea
+WORKDIR $GOPATH/src/github.com/purpleidea
+RUN git clone --recursive https://github.com/purpleidea/mgmt mgmt
+WORKDIR $GOPATH/src/github.com/purpleidea/mgmt
+RUN make deps
+RUN make build
+CMD ["/bin/bash"]

docker/Dockerfile.build

@@ -0,0 +1,12 @@
+FROM centos:7
+MAINTAINER Karim Boumedhel <karimboumedhel@gmail.com>
+
+ENV GOPATH=/root/gopath
+ENV PATH=/opt/rh/rh-ruby22/root/usr/bin:/root/gopath/bin:/usr/local/sbin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/go/bin
+ENV LD_LIBRARY_PATH=/opt/rh/rh-ruby22/root/usr/lib64${LD_LIBRARY_PATH:+:${LD_LIBRARY_PATH}}
+ENV PKG_CONFIG_PATH=/opt/rh/rh-ruby22/root/usr/lib64/pkgconfig${PKG_CONFIG_PATH:+:${PKG_CONFIG_PATH}}
+
+RUN yum -y install epel-release wget unzip git make which centos-release-scl gcc && sed -i "s/enabled=0/enabled=1/" /etc/yum.repos.d/epel-testing.repo && yum -y install rh-ruby22 && wget -O /opt/go1.23.5.linux-amd64.tar.gz https://storage.googleapis.com/golang/go1.23.5.linux-amd64.tar.gz && tar -C /usr/local -xzf /opt/go1.23.5.linux-amd64.tar.gz
+RUN mkdir -p $GOPATH/src/github.com/purpleidea && cd $GOPATH/src/github.com/purpleidea && git clone --recursive https://github.com/purpleidea/mgmt
+RUN go get -u gopkg.in/alecthomas/gometalinter.v1 && cd $GOPATH/src/github.com/purpleidea/mgmt && make deps && make build
+CMD ["/bin/bash"]

docker/Dockerfile.development

@@ -1,10 +1,10 @@
-FROM golang:1.6.2
+FROM golang:1.23
 
 MAINTAINER Michał Czeraszkiewicz <contact@czerasz.com>
 
 # Set the reset cache variable
 # Read more here: http://czerasz.com/2014/11/13/docker-tip-and-tricks/#use-refreshedat-variable-for-better-cache-control
-ENV REFRESHED_AT 2016-05-14
+ENV REFRESHED_AT 2019-02-06
 
 RUN apt-get update
 

docker/Dockerfile.static

@@ -0,0 +1,9 @@
+FROM centos:7
+MAINTAINER Karim Boumedhel <karimboumedhel@gmail.com>
+
+RUN yum -y install augeas-libs libvirt-libs && yum clean all
+ADD mgmt /usr/bin
+RUN chmod 700 /usr/bin/mgmt
+
+ENTRYPOINT ["/usr/bin/mgmt"]
+CMD ["-h"]

docker/scripts/build

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 script_directory="$( cd "$( dirname "$0" )" && pwd )"
 project_directory=$script_directory/../..

docker/scripts/build-development

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Stop on any error
 set -e

docker/scripts/exec-development

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+
+# runs command provided as argument inside a development (Linux) Docker container
+
+# Stop on any error
+set -e
+
+script_directory="$( cd "$( dirname "$0" )" && pwd )"
+project_directory=$script_directory/../..
+
+# Specify the Docker image name
+image_name='purpleidea/mgmt:development'
+
+# Run container in development mode
+docker run --rm --name=mgm_development --user=mgmt \
+	-v "$project_directory:/go/src/github.com/purpleidea/mgmt/" \
+	-w /go/src/github.com/purpleidea/mgmt/ \
+	-it "$image_name" /bin/bash -c "$*"

docker/scripts/run-development

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Stop on any error
 set -e

docs/.gitignore

@@ -0,0 +1,2 @@
+mgmt-documentation.pdf
+_build

docs/Makefile

@@ -0,0 +1,20 @@
+# Minimal makefile for Sphinx documentation
+#
+
+# You can set these variables from the command line.
+SPHINXOPTS    =
+SPHINXBUILD   = sphinx-build
+SPHINXPROJ    = mgmt
+SOURCEDIR     = .
+BUILDDIR      = _build
+
+# Put it first so that "make" without argument is like "make help".
+help:
+	@$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
+
+.PHONY: help Makefile
+
+# Catch-all target: route all unknown targets to Sphinx using the new
+# "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
+%: Makefile
+	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)

docs/conf.py

@@ -0,0 +1,158 @@
+# -*- coding: utf-8 -*-
+#
+# mgmt documentation build configuration file, created by
+# sphinx-quickstart on Wed Feb 15 21:34:09 2017.
+#
+# This file is execfile()d with the current directory set to its
+# containing dir.
+#
+# Note that not all possible configuration values are present in this
+# autogenerated file.
+#
+# All configuration values have a default; values that are commented out
+# serve to show the default.
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+#
+# import os
+# import sys
+# sys.path.insert(0, os.path.abspath('.'))
+
+from recommonmark.parser import CommonMarkParser
+
+# -- General configuration ------------------------------------------------
+
+# If your documentation needs a minimal Sphinx version, state it here.
+#
+# needs_sphinx = '1.0'
+
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+# ones.
+extensions = []
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['_templates']
+
+# The suffix(es) of source filenames.
+# You can specify multiple suffix as a list of string:
+#
+
+source_parsers = {
+        '.md': CommonMarkParser,
+}
+
+source_suffix = ['.rst', '.md']
+
+# The master toctree document.
+master_doc = 'index'
+
+# General information about the project.
+project = u'mgmt'
+copyright = u'Copyright (C) James Shubin and the project contributors'
+author = u'James Shubin'
+
+# The version info for the project you're documenting, acts as replacement for
+# |version| and |release|, also used in various other places throughout the
+# built documents.
+#
+# The short X.Y version.
+version = u''
+# The full version, including alpha/beta/rc tags.
+release = u''
+
+# The language for content autogenerated by Sphinx. Refer to documentation
+# for a list of supported languages.
+#
+# This is also used if you do content translation via gettext catalogs.
+# Usually you set "language" from the command line for these cases.
+language = None
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+# This patterns also effect to html_static_path and html_extra_path
+exclude_patterns = ['_build', 'Thumbs.db', '.DS_Store', 'venv']
+
+# The name of the Pygments (syntax highlighting) style to use.
+pygments_style = 'sphinx'
+
+# If true, `todo` and `todoList` produce output, else they produce nothing.
+todo_include_todos = False
+
+
+# -- Options for HTML output ----------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+#
+#html_theme = 'alabaster'
+
+# Theme options are theme-specific and customize the look and feel of a theme
+# further.  For a list of options available for each theme, see the
+# documentation.
+#
+# html_theme_options = {}
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+html_static_path = ['_static']
+
+
+# -- Options for HTMLHelp output ------------------------------------------
+
+# Output file base name for HTML help builder.
+htmlhelp_basename = 'mgmtdoc'
+
+
+# -- Options for LaTeX output ---------------------------------------------
+
+latex_elements = {
+    # The paper size ('letterpaper' or 'a4paper').
+    #
+    # 'papersize': 'letterpaper',
+
+    # The font size ('10pt', '11pt' or '12pt').
+    #
+    # 'pointsize': '10pt',
+
+    # Additional stuff for the LaTeX preamble.
+    #
+    # 'preamble': '',
+
+    # Latex figure (float) alignment
+    #
+    # 'figure_align': 'htbp',
+}
+
+# Grouping the document tree into LaTeX files. List of tuples
+# (source start file, target name, title,
+#  author, documentclass [howto, manual, or own class]).
+latex_documents = [
+    (master_doc, 'mgmt.tex', u'mgmt Documentation',
+     u'James Shubin', 'manual'),
+]
+
+
+# -- Options for manual page output ---------------------------------------
+
+# One entry per manual page. List of tuples
+# (source start file, name, description, authors, manual section).
+man_pages = [
+    (master_doc, 'mgmt', u'mgmt Documentation',
+     [author], 1)
+]
+
+
+# -- Options for Texinfo output -------------------------------------------
+
+# Grouping the document tree into Texinfo files. List of tuples
+# (source start file, target name, title, author,
+#  dir menu entry, description, category)
+texinfo_documents = [
+    (master_doc, 'mgmt', u'mgmt Documentation',
+     author, 'mgmt', 'Next generation distributed, event-driven, parallel config management!',
+     'Miscellaneous'),
+]

docs/contributing.md

@@ -0,0 +1,96 @@
+# Contributing
+
+What follows is a short guide with information for participants who wish to
+contribute to the project. It hopes to set both some expectations and boundaries
+so that we both benefit.
+
+## Small patches
+
+If you have a small patch which you believe is straightforward, should be easy
+to merge, and isn't overly onerous on your time to write, please feel free to
+send it our way without asking first. Bug fixes are excellent examples of small
+patches. Please make sure to familiarize yourself with the rough coding style of
+the project first, and read through the [style guide](style-guide.md).
+
+## Making an excellent small patch
+
+As a special case: We'd like to avoid minimal effort, one-off, drive-by patches
+by bots and contributors looking to increase their "activity" numbers. As an
+example: a patch which fixes a small linting issue isn't rousing, but a patch
+that adds a linter test _and_ fixes a small linting issue is, because it shows
+you put in more effort.
+
+## Medium patches
+
+Medium sized patches are especially welcome. Good examples of these patches
+can include writing a new `mgmt` resource or function. You'll generally need
+some knowledge of golang interfaces and concurrency to write these patches.
+Before writing one of these, please make sure you understand some basics about
+the project and how the tool works. After this, it is recommended that you join
+our discussion channel to suggest the idea, and ideally include the actual API
+you'd like to propose before writing the code and sending a patch.
+
+## Making an excellent medium patch proposal
+
+The "API" of a resource is the type signature of the resource struct, and the
+"API" of a function is the type signature or signatures that it supports. (Since
+functions can be polymorphic, more than one signature can be possible!) A good
+proposal would likely also comment on the mechanisms the resources or functions
+would use to watch for events, to check state, and to apply changes. If these
+mechanisms need new dependencies, a brief survey of which dependencies are
+available and why you recommend a particular one is encouraged.
+
+## Large patches or structural and core patches
+
+Please do not send us large, core or structurally significant patches without
+first getting our approval and without getting some medium patches in first.
+These patches take a lot of effort to review, and we don't want to skimp on our
+commitment to that if we can't muster it. Instead grow our relationship with you
+on the medium-sized patches first. (A core patch might refer to something that
+touches either the function engine, resource engine, compiler internals, or
+something that is part of one of the internal API's.)
+
+## Expectations and boundaries
+
+When interacting with the project and soliciting feedback (either for design or
+during a code review) please keep in mind that the project (unfortunately!) has
+time constraints and so must prioritize how it handles workloads. If you are
+someone who has successfully sent in small patches, we will be more willing to
+spend time mentoring your medium sized patches and so on. Think of it this way:
+as you show that you're contributing to the project, we'll contribute more to
+you. Put another way: we can't afford to spend large amounts of time discussing
+potential patches with you, just to end up nowhere. Build up your reputation
+with us, and we hope to help grow our symbiosis with you all the while as you
+grow too!
+
+## Energy output
+
+The same goes for users and issue creators. There are times when we simply don't
+have the cycles to discuss or litigate an issue with you. We wish we did have
+more time, but it is finite, and running a project is not free. Therefore,
+please keep in mind that you don't automatically qualify for free support or
+attention.
+
+## Attention seeking behaviours
+
+Some folks spend too much time starting discussions, commenting on issues,
+"planning" and otherwise displaying attention seeking behaviours. Please avoid
+doing this as much as possible, especially if you are not already a major
+contributor to the project. While it may be well intentioned, if it is
+indistinguishable to us from intentional interference, then it's not welcome
+behaviour. Remember that Free Software is not free to write. If you require more
+attention, then either contribute more to the project, or consider paying for a
+[support contract](https://mgmtconfig.com/).
+
+## Consulting
+
+Having said all that, there are some folks who want to do some longer-term
+planning to decide if our core design and architecture is right for them to
+invest in. If that's the case, and you aren't already a well-known project
+contributor, please [contact](https://mgmtconfig.com/) us for a consulting
+quote. We have packages available for both individuals and businesses.
+
+## Respect
+
+Please be mindful and respectful of others when interacting with the project and
+its contributors. If you cannot abide by that, you may no longer be welcome.

docs/development.md

@@ -0,0 +1,163 @@
+# Development
+
+This document contains some additional information and help regarding
+developing `mgmt`. Useful tools, conventions, etc.
+
+Be sure to read [quick start guide](quick-start-guide.md) first.
+
+## Vagrant
+
+If you would like to avoid doing the above steps manually, we have prepared a
+[Vagrant](https://www.vagrantup.com/) environment for your convenience. From the
+project directory, run a `vagrant up`, and then a `vagrant status`. From there,
+you can `vagrant ssh` into the `mgmt` machine. The `MOTD` will explain the rest.
+This environment isn't commonly used by the `mgmt` developers, so it might not
+be working properly.
+
+## Using Docker
+
+Alternatively, you can check out the [docker folder](../docker/) in order to
+develop or deploy using docker. This method is not endorsed or supported, so use
+at your own risk, as it might not be working properly.
+
+## Information about dependencies
+
+Software projects have a few different kinds of dependencies. There are _build_
+dependencies, _runtime_ dependencies, and additionally, a few extra dependencies
+required for running the _test_ suite.
+
+### Build
+
+* A modern `golang` version. The version available in the current Fedora
+releases is usually supported. This is also distributed as a binary officially
+by [golang.org](https://golang.org/dl/).
+
+### Runtime
+
+A relatively modern GNU/Linux system should be able to run `mgmt` without any
+problems. Since `mgmt` runs as a single statically compiled binary, all of the
+library dependencies are included. It is expected, that certain advanced
+resources require host specific facilities to work. These requirements are
+listed below:
+
+| Resource | Dependency        | Version                     | Check version with                                        |
+|----------|-------------------|-----------------------------|-----------------------------------------------------------|
+| augeas   | augeas-devel      | `augeas 1.6` or greater     | `dnf info augeas-devel` or `apt-cache show libaugeas-dev` |
+| file     | inotify           | `Linux 2.6.27` or greater   | `uname -a`                                                |
+| hostname | systemd-hostnamed | `systemd 25` or greater     | `systemctl --version`                                     |
+| nspawn   | systemd-nspawn    | `systemd ???` or greater    | `systemctl --version`                                     |
+| pkg      | packagekitd       | `packagekit 1.x` or greater | `pkcon --version`                                         |
+| svc      | systemd           | `systemd ???` or greater    | `systemctl --version`                                     |
+| virt     | libvirt-devel     | `libvirt 1.2.0` or greater  | `dnf info libvirt-devel` or `apt-cache show libvirt-dev`  |
+| virt     | libvirtd          | `libvirt 1.2.0` or greater  | `libvirtd --version`                                      |
+
+For building a visual representation of the graph, `graphviz` is required.
+
+To build `mgmt` without augeas support please run:
+`GOTAGS='noaugeas' make build`
+
+To build `mgmt` without libvirt support please run:
+`GOTAGS='novirt' make build`
+
+To build `mgmt` without docker support please run:
+`GOTAGS='nodocker' make build`
+
+To build `mgmt` without augeas, libvirt or docker support please run:
+`GOTAGS='noaugeas novirt nodocker' make build`
+
+## OSX/macOS/Darwin development
+
+Developing and running `mgmt` on macOS is currently not supported (but not
+discouraged either). Meaning it might work but in the case it doesn't you would
+have to provide your own patches to fix problems (the project maintainer and
+community are glad to assist where needed).
+
+There are currently some issues that make `mgmt` less suitable to run for
+provisioning macOS. But as a client to provision remote servers it should run
+fine.
+
+Since the primary supported systems are Linux and these are the environments
+tested, it is wise to run these suites during macOS development as well. To ease
+this, Docker can be leveraged ([Docker for Mac](https://docs.docker.com/docker-for-mac/)).
+
+Before running any of the commands below create the development Docker image:
+
+```
+docker/scripts/build-development
+```
+
+This image requires updating every time dependencies (`make-deps.sh`) changes.
+
+Then to run the test suite:
+
+```
+docker run --rm -ti \
+	-v $PWD:/go/src/github.com/purpleidea/mgmt/ \
+	-w /go/src/github.com/purpleidea/mgmt/ \
+	purpleidea/mgmt:development \
+	make test
+```
+
+For convenience this command is wrapped in `docker/scripts/exec-development`.
+
+Basically any command can be executed this way. Because the repository source is
+mounted into the Docker container invocation will be quick and allow rapid
+testing, for example:
+
+```
+docker/scripts/exec-development test/test-shell.sh load0.sh
+```
+
+Other examples:
+
+```
+docker/scripts/exec-development make build
+docker/scripts/exec-development ./mgmt run --tmp-prefix lang examples/lang/load0.mcl
+```
+
+Be advised that this method is not supported and it might not be working
+properly.
+
+## Testing
+
+This project has both unit tests in the form of golang tests and integration
+tests using shell scripting.
+
+Native golang tests are preferred over tests written in our shell testing
+framework. Please see [https://golang.org/pkg/testing/](https://golang.org/pkg/testing/)
+for more information.
+
+To run all tests:
+
+```
+make test
+```
+
+There is a library of quick and small integration tests for the language and
+YAML related things, check out [`test/shell/`](/test/shell). Adding a test is as
+easy as copying one of the files in [`test/shell/`](/test/shell) and adapting
+it.
+
+This test suite won't run by default (unless when on CI server) and needs to be
+called explicitly using:
+
+```
+make test-shell
+```
+
+Or run an individual shell test using:
+
+```
+make test-shell-load0
+```
+
+Tip: you can use TAB completion with `make` to quickly get a list of possible
+individual tests to run.
+
+## Tools, integrations, IDE's etc
+
+### IDE/Editor support
+
+* Emacs: see `misc/emacs/`
+* [Textmate](https://github.com/aequitas/mgmt.tmbundle)
+* [VSCode](https://github.com/aequitas/mgmt.vscode)

docs/docs.go

@@ -0,0 +1,50 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+// Package docs provides a tool that generates documentation from the source.
+//
+// ./mgmt docs generate --output /tmp/docs.json && cat /tmp/docs.json | jq
+package docs
+
+import (
+	"context"
+)
+
+// API is the simple interface we expect for any setup items.
+type API interface {
+	// Main runs everything for this setup item.
+	Main(context.Context) error
+}
+
+// Config is a struct of all the configuration values which are shared by all of
+// the setup utilities. By including this as a separate struct, it can be used
+// as part of the API if we want.
+type Config struct {
+	//Foo string `arg:"--foo,env:MGMT_DOCGEN_FOO" help:"Foo..."` // TODO: foo
+}

docs/documentation.md

@@ -0,0 +1,547 @@
+# General documentation
+
+## Overview
+
+The `mgmt` tool is a next generation config management solution. It's ready for
+production, and we hope you try out the future soon. Get involved today!
+
+## Project Description
+
+The mgmt tool is a distributed, event driven, config management tool, that
+supports parallel execution, and librarification to be used as the management
+foundation in and for, new and existing software.
+
+For more information, you may like to read some blog posts from the author:
+
+* [Next generation config mgmt](https://purpleidea.com/blog/2016/01/18/next-generation-configuration-mgmt/)
+* [Automatic edges in mgmt](https://purpleidea.com/blog/2016/03/14/automatic-edges-in-mgmt/)
+* [Automatic grouping in mgmt](https://purpleidea.com/blog/2016/03/30/automatic-grouping-in-mgmt/)
+* [Automatic clustering in mgmt](https://purpleidea.com/blog/2016/06/20/automatic-clustering-in-mgmt/)
+* [Remote execution in mgmt](https://purpleidea.com/blog/2016/10/07/remote-execution-in-mgmt/)
+* [Send/Recv in mgmt](https://purpleidea.com/blog/2016/12/07/sendrecv-in-mgmt/)
+* [Metaparameters in mgmt](https://purpleidea.com/blog/2017/03/01/metaparameters-in-mgmt/)
+
+There is also an [introductory video](https://www.youtube.com/watch?v=LkEtBVLfygE&html5=1)
+available. Older videos and other material [is available](on-the-web.md).
+
+## Setup
+
+You'll probably want to read the [quick start guide](quick-start-guide.md) to
+get going.
+
+## Features
+
+This section details the numerous features of mgmt and some caveats you might
+need to be aware of.
+
+### Autoedges
+
+Automatic edges, or AutoEdges, is the mechanism in mgmt by which it will
+automatically create dependencies for you between resources. For example,
+since mgmt can discover which files are installed by a package it will
+automatically ensure that any file resource you declare that matches a
+file installed by your package resource will only be processed after the
+package is installed.
+
+#### Controlling autoedges
+
+Though autoedges is likely to be very helpful and avoid you having to declare
+all dependencies explicitly, there are cases where this behaviour is
+undesirable.
+
+Some distributions allow package installations to automatically start the
+service they ship. This can be problematic in the case of packages like MySQL
+as there are configuration options that need to be set before MySQL is ever
+started for the first time (or you'll need to wipe the data directory). In
+order to handle this situation you can disable autoedges per resource and
+explicitly declare that you want `my.cnf` to be written to disk before the
+installation of the `mysql-server` package.
+
+You can disable autoedges for a resource by setting the `autoedge` key on
+the meta attributes of that resource to `false`.
+
+#### Blog post
+
+You can read the introductory blog post about this topic here:
+[https://purpleidea.com/blog/2016/03/14/automatic-edges-in-mgmt/](https://purpleidea.com/blog/2016/03/14/automatic-edges-in-mgmt/)
+
+### Autogrouping
+
+Automatic grouping or AutoGroup is the mechanism in mgmt by which it will
+automatically group multiple resource vertices into a single one. This is
+particularly useful for grouping multiple package resources into a single
+resource, since the multiple installations can happen together in a single
+transaction, which saves a lot of time because package resources typically have
+a large fixed cost to running (downloading and verifying the package repo) and
+if they are grouped they share this fixed cost. This grouping feature can be
+used for other use cases too.
+
+You can disable autogrouping for a resource by setting the `autogroup` key on
+the meta attributes of that resource to `false`.
+
+#### Blog post
+
+You can read the introductory blog post about this topic here:
+[https://purpleidea.com/blog/2016/03/30/automatic-grouping-in-mgmt/](https://purpleidea.com/blog/2016/03/30/automatic-grouping-in-mgmt/)
+
+### Automatic clustering
+
+Automatic clustering is a feature by which mgmt automatically builds, scales,
+and manages the embedded etcd cluster which is compiled into mgmt itself. It is
+quite helpful for rapidly bootstrapping clusters and avoiding the extra work to
+setup etcd.
+
+If you prefer to avoid this feature. you can always opt to use an existing etcd
+cluster that is managed separately from mgmt by pointing your mgmt agents at it
+with the `--seeds` variable.
+
+#### Blog post
+
+You can read the introductory blog post about this topic here:
+[https://purpleidea.com/blog/2016/06/20/automatic-clustering-in-mgmt/](https://purpleidea.com/blog/2016/06/20/automatic-clustering-in-mgmt/)
+
+### Remote ("agent-less") mode
+
+Remote mode is a special mode that lets you kick off mgmt runs on one or more
+remote machines which are only accessible via SSH. In this mode the initiating
+host connects over SSH, copies over the `mgmt` binary, opens an SSH tunnel, and
+runs the remote program while simultaneously passing the etcd traffic back
+through the tunnel so that the initiators etcd cluster can be used to exchange
+resource data.
+
+The interesting benefit of this architecture is that multiple hosts which can't
+connect directly use the initiator to pass the important traffic through to each
+other. Once the cluster has converged all the remote programs can shutdown
+leaving no residual agent.
+
+This mode can also be useful for bootstrapping a new host where you'd like to
+have the service run continuously and as part of an mgmt cluster normally.
+
+In particular, when combined with the `--converged-timeout` parameter, the
+entire set of running mgmt agents will need to all simultaneously converge for
+the group to exit. This is particularly useful for bootstrapping new clusters
+which need to exchange information that is only available at run time.
+
+This existed in earlier versions of mgmt as a `--remote` option, but it has been
+removed and is being ported to a more powerful variant where you can remote
+execute via a `remote` resource.
+
+#### Blog post
+
+You can read the introductory blog post about this topic here:
+[https://purpleidea.com/blog/2016/10/07/remote-execution-in-mgmt/](https://purpleidea.com/blog/2016/10/07/remote-execution-in-mgmt/)
+
+### Puppet support
+
+You can supply a puppet manifest instead of creating the (YAML) graph manually.
+Puppet must be installed and in `mgmt`'s search path. You also need the
+[ffrank-mgmtgraph puppet module](https://forge.puppet.com/ffrank/mgmtgraph).
+
+Invoke `mgmt` with the `--puppet` switch, which supports 3 variants:
+
+1. Request the configuration from the puppet server (like `puppet agent` does)
+
+	`mgmt run puppet --puppet agent`
+
+2. Compile a local manifest file (like `puppet apply`)
+
+	`mgmt run puppet --puppet /path/to/my/manifest.pp`
+
+3. Compile an ad hoc manifest from the commandline (like `puppet apply -e`)
+
+	`mgmt run puppet --puppet 'file { "/etc/ntp.conf": ensure => file }'`
+
+For more details and caveats see [puppet-guide.md](puppet-guide.md).
+
+#### Blog post
+
+An introductory post on the puppet support is on
+[Felix's blog](http://ffrank.github.io/features/2016/06/19/puppet-powered-mgmt/).
+
+## Reference
+
+Please note that there are a number of undocumented options. For more
+information on these options, please view the source at:
+[https://github.com/purpleidea/mgmt/](https://github.com/purpleidea/mgmt/).
+If you feel that a well used option needs documenting here, please patch it!
+
+### Overview of reference
+
+* [Meta parameters](#meta-parameters): List of available resource meta parameters.
+* [Lang metadata file](#lang-metadata-file): Lang metadata file format.
+* [Graph definition file](#graph-definition-file): Main graph definition file.
+* [Command line](#command-line): Command line parameters.
+* [Compilation options](#compilation-options): Compilation options.
+
+### Meta parameters
+
+These meta parameters are special parameters (or properties) which can apply to
+any resource. The usefulness of doing so will depend on the particular meta
+parameter and resource combination.
+
+#### AutoEdge
+
+Boolean. Should we generate auto edges for this resource?
+
+#### AutoGroup
+
+Boolean. Should we attempt to automatically group this resource with others?
+
+#### Noop
+
+Boolean. Should the Apply portion of the CheckApply method of the resource
+make any changes? Noop is a concatenation of no-operation.
+
+#### Retry
+
+Integer. The number of times to retry running the resource on error. Use -1 for
+infinite. This currently applies for both the Watch operation (which can fail)
+and for the CheckApply operation. While they could have separate values, I've
+decided to use the same ones for both until there's a proper reason to want to
+do something differently for the Watch errors.
+
+#### Delay
+
+Integer. Number of milliseconds to wait between retries. The same value is
+shared between the Watch and CheckApply retries. This currently applies for both
+the Watch operation (which can fail) and for the CheckApply operation. While
+they could have separate values, I've decided to use the same ones for both
+until there's a proper reason to want to do something differently for the Watch
+errors.
+
+#### Poll
+
+Integer. Number of seconds to wait between `CheckApply` checks. If this is
+greater than zero, then the standard event based `Watch` mechanism for this
+resource is replaced with a simple polling mechanism. In general, this is not
+recommended, unless you have a very good reason for doing so.
+
+Please keep in mind that if you have a resource which changes every `I` seconds,
+and you poll it every `J` seconds, and you've asked for a converged timeout of
+`K` seconds, and `I <= J <= K`, then your graph will likely never converge.
+
+When polling, the system detects that a resource is not converged if its
+`CheckApply` method returns false. This allows a resource which changes every
+`I` seconds, and which is polled every `J` seconds, and with a converged timeout
+of `K` seconds to still converge when `J <= K`, as long as `I > J || I > K`,
+which is another way of saying that if the resource finally settles down to give
+the graph enough time, it can probably converge.
+
+#### Limit
+
+Float. Maximum rate of `CheckApply` runs started per second. Useful to limit
+an especially _eventful_ process from causing excessive checks to run. This
+defaults to `+Infinity` which adds no limiting. If you change this value, you
+will also need to change the `Burst` value to a non-zero value. Please see the
+[rate](https://godoc.org/golang.org/x/time/rate) package for more information.
+
+#### Burst
+
+Integer. Burst is the maximum number of runs which can happen without invoking
+the rate limiter as designated by the `Limit` value. If the `Limit` is not set
+to `+Infinity`, this must be a non-zero value. Please see the
+[rate](https://godoc.org/golang.org/x/time/rate) package for more information.
+
+#### Sema
+
+List of string ids. Sema is a P/V style counting semaphore which can be used to
+limit parallelism during the CheckApply phase of resource execution. Each
+resource can have `N` different semaphores which share a graph global namespace.
+Each semaphore has a maximum count associated with it. The default value of the
+size is 1 (one) if size is unspecified. Each string id is the unique id of the
+semaphore. If the id contains a trailing colon (:) followed by a positive
+integer, then that value is the max size for that semaphore. Valid semaphore
+id's include: `some_id`, `hello:42`, `not:smart:4` and `:13`. It is expected
+that the last bare example be only used by the engine to add a global semaphore.
+
+#### Rewatch
+
+Boolean. Rewatch specifies whether we re-run the Watch worker during a graph
+swap if it has errored. When doing a graph compare to swap the graphs, if this
+is true, and this particular worker has errored, then we'll remove it and add it
+back as a new vertex, thus causing it to run again. This is different from the
+`Retry` metaparam which applies during the normal execution. It is only when
+this is exhausted that we're in permanent worker failure, and only then can we
+rely on this metaparam.
+
+#### Realize
+
+Boolean. Realize ensures that the resource is guaranteed to converge at least
+once before a potential graph swap removes or changes it. This guarantee is
+useful for fast changing graphs, to ensure that the brief creation of a resource
+is seen. This guarantee does not prevent against the engine quitting normally,
+and it can't guarantee it if the resource is blocked because of a failed
+pre-requisite resource.
+*XXX: This is currently not implemented!*
+
+#### Dollar
+
+Boolean. Dollar allows you to have a resource name that starts with a `$` sign.
+This is false by default. This helps you catch cases when you write code like:
+
+```mcl
+$foo = "/tmp/file1"
+file "$foo" {} # incorrect!
+```
+
+The above code would ignore the `$foo` variable and attempt to make a file named
+`$foo` which would obviously not work. To correctly interpolate a variable, you
+need to surround the name with curly braces.
+
+```mcl
+$foo = "/tmp/file1"
+file "${foo}" {} # correct!
+```
+
+This meta param is a safety measure to make your life easier. It works for all
+resources. If someone comes up with a resource which would routinely start with
+a dollar sign, then we can revisit the default for this resource kind.
+
+#### Hidden
+
+Boolean. Hidden means that this resource will not get executed on the resource
+graph on which it is defined. This can be used as a simple boolean switch, or,
+more commonly in combination with the Export meta param which specifies that the
+resource params are exported into the shared database. When this is true, it
+does not prevent export. In fact, it is commonly used in combination with
+Export. Using this option will still include it in the resource graph, but it
+will exist there in a special "mode" where it will not conflict with any other
+identically named resources. It can even be used as part of an edge or via a
+send/recv receiver. It can NOT be a sending vertex. These properties
+differentiate the use of this instead of simply wrapping a resource in an "if"
+statement.
+
+#### Export
+
+List of strings. Export is a list of hostnames (and/or the special "*" entry)
+which if set, will mark this resource data as intended for export to those
+hosts. This does not prevent any users of the shared data storage from reading
+these values, so if you want to guarantee secrecy, use the encryption
+primitives. This only labels the data accordingly, so that other hosts can know
+what data is available for them to collect. The (kind, name, host) export triple
+must be unique from any given exporter. In other words, you may not export two
+different instances of a kind+name to the same host, the exports must not
+conflict. On resource collect, this parameter is not preserved.
+
+```mcl
+file "/tmp/foo" {
+	state => "exists",
+	content => "i'm exported!\n",
+
+	Meta:hidden => true,
+	Meta:export => ["h1",],
+}
+
+file "/tmp/foo" {
+	state => "exists",
+	content => "i'm exported AND i'm used here\n",
+
+	Meta:export => ["h1",],
+}
+```
+
+#### Reverse
+
+Boolean. Reverse is a property that some resources can implement that specifies
+that some "reverse" operation should happen when that resource "disappears". A
+disappearance happens when a resource is defined in one instance of the graph,
+and is gone in the subsequent one. This disappearance can happen if it was
+previously in an if statement that then becomes false.
+
+This is helpful for building robust programs with the engine. The engine adds a
+"reversed" resource to that subsequent graph to accomplish the desired "reverse"
+mechanics. The specifics of what this entails is a property of the particular
+resource that is being "reversed".
+
+It might be wise to combine the use of this meta parameter with the use of the
+`realize` meta parameter to ensure that your reversed resource actually runs at
+least once, if there's a chance that it might be gone for a while.
+
+### Lang metadata file
+
+Any module *must* have a metadata file in its root. It must be named
+`metadata.yaml`, even if it's empty. You can specify zero or more values in yaml
+format which can change how your module behaves, and where the `mcl` language
+looks for code and other files. The most important top level keys are: `main`,
+`path`, `files`, and `license`.
+
+#### Main
+
+The `main` key points to the default entry point of your code. It must be a
+relative path if specified. If it's empty it defaults to `main.mcl`. It should
+generally not be changed. It is sometimes set to `main/main.mcl` if you'd like
+your modules code out of the root and into a child directory for cases where you
+don't plan on having a lot deeper imports relative to `main.mcl` and all those
+files would clutter things up.
+
+#### Path
+
+The `path` key specifies the modules import search directory to use for this
+module. You can specify this if you'd like to vendor something for your module.
+In general, if you use it, please use the convention: `path/`. If it's not
+specified, you will default to the parent modules directory.
+
+#### Files
+
+The `files` key specifies some additional files that will get included in your
+deploy. It defaults to `files/`.
+
+#### License
+
+The `license` key allows you to specify a license for the module. Please specify
+one so that everyone can enjoy your code! Use a "short license identifier", like
+`LGPLv3+`, or `MIT`. The former is a safe choice if you're not sure what to use.
+
+### Graph definition file
+
+graph.yaml is the compiled graph definition file. The format is currently
+undocumented, but by looking through the [examples/](https://github.com/purpleidea/mgmt/tree/master/examples/yaml/)
+you can probably figure out most of it, as it's fairly intuitive. It's not
+recommended that you use this, since it's preferable to write code in the
+[mcl language](language-guide.md) front-end.
+
+### Command line
+
+The main interface to the `mgmt` tool is the command line. For the most recent
+documentation, please run `mgmt --help`.
+
+#### `--converged-timeout <seconds>`
+
+Exit if the machine has converged for approximately this many seconds.
+
+#### `--max-runtime <seconds>`
+
+Exit when the agent has run for approximately this many seconds. This is not
+generally recommended, but may be useful for users who know what they're doing.
+
+#### `--noop`
+
+Globally force all resources into no-op mode. This also disables the export to
+etcd functionality, but does not disable resource collection, however all
+resources that are collected will have their individual noop settings set.
+
+#### `--sema <size>`
+
+Globally add a counting semaphore of this size to each resource in the graph.
+The semaphore will get given an id of `:size`. In other words if you specify a
+size of 42, you can expect a semaphore if named: `:42`. It is expected that
+consumers of the semaphore metaparameter always include a prefix to avoid a
+collision with this globally defined semaphore. The size value must be greater
+than zero at this time. The traditional non-parallel execution found in config
+management tools such as `puppet` can be obtained with `--sema 1`.
+
+#### `--ssh-priv-id-rsa`
+
+Specify the path for finding SSH keys. This defaults to `~/.ssh/id_rsa`. To
+never use this method of authentication, set this to the empty string.
+
+#### `--prefix <path>`
+
+Specify a path to a custom working directory prefix. This directory will get
+created if it does not exist. This usually defaults to `/var/lib/mgmt/`. This
+can't be combined with the `--tmp-prefix` option. It can be combined with the
+`--allow-tmp-prefix` option.
+
+#### `--tmp-prefix`
+
+If this option is specified, a temporary prefix will be used instead of the
+default prefix. This can't be combined with the `--prefix` option.
+
+#### `--allow-tmp-prefix`
+
+If this option is specified, we will attempt to fall back to a temporary prefix
+if the primary prefix couldn't be created. This is useful for avoiding failures
+in environments where the primary prefix may or may not be available, but you'd
+like to try. The canonical example is when running `mgmt` with remote execution
+there might be a cached copy of the binary in the primary prefix, but if there's
+no binary available continue working in a temporary directory to avoid failure.
+
+### Compilation options
+
+You can control some compilation variables by using environment variables.
+
+#### Disable libvirt support
+
+If you wish to compile mgmt without libvirt, you can use the following command:
+
+```
+GOTAGS=novirt make build
+```
+
+#### Disable augeas support
+
+If you wish to compile mgmt without augeas support, you can use the following
+command:
+
+```
+GOTAGS=noaugeas make build
+```
+
+#### Disable docker support
+
+If you wish to compile mgmt without docker support, you can use the following
+command:
+
+```
+GOTAGS=nodocker make build
+```
+
+#### Combining compile-time flags
+
+You can combine multiple tags by using a space-separated list:
+
+```
+GOTAGS="noaugeas novirt nodocker" make build
+```
+
+## Examples
+
+For example configurations, please consult the [examples/](https://github.com/purpleidea/mgmt/tree/master/examples)
+directory in the git source repository. It is available from:
+
+[https://github.com/purpleidea/mgmt/tree/master/examples](https://github.com/purpleidea/mgmt/tree/master/examples)
+
+### Systemd:
+
+See [`misc/mgmt.service`](../misc/mgmt.service) for a sample systemd unit file.
+This unit file is part of the RPM.
+
+To specify your custom options for `mgmt` on a systemd distro:
+
+```bash
+sudo mkdir -p /etc/systemd/system/mgmt.service.d/
+
+cat > /etc/systemd/system/mgmt.service.d/env.conf <<EOF
+# Environment variables:
+MGMT_SEEDS=http://127.0.0.1:2379
+MGMT_CONVERGED_TIMEOUT=-1
+MGMT_MAX_RUNTIME=0
+
+# Other CLI options if necessary.
+#OPTS="--max-runtime=0"
+EOF
+
+sudo systemctl daemon-reload
+```
+
+## Development
+
+This is a project that I started in my free time in 2013. Development is driven
+by all of our collective patches! Dive right in, and start hacking!
+Please contact me if you'd like to invite me to speak about this at your event.
+
+You can follow along [on my technical blog](https://purpleidea.com/blog/).
+
+To report any bugs, please file a ticket at: [https://github.com/purpleidea/mgmt/issues](https://github.com/purpleidea/mgmt/issues).
+
+## Authors
+
+Copyright (C) James Shubin and the project contributors
+
+Please see the
+[AUTHORS](https://github.com/purpleidea/mgmt/tree/master/AUTHORS) file
+for more information.
+
+* [github](https://github.com/purpleidea/)
+* [&#64;purpleidea](https://twitter.com/#!/purpleidea)
+* [https://purpleidea.com/](https://purpleidea.com/)

docs/faq.md

@@ -0,0 +1,537 @@
+## Frequently asked questions
+
+(Send your questions as a patch to this FAQ! I'll review it, merge it, and
+respond by commit with the answer.)
+
+### Why did you start this project?
+
+I wanted a next generation config management solution that didn't have all of
+the design flaws or limitations that the current generation of tools do, and no
+tool existed!
+
+### Why did you choose `golang` for the project?
+
+When I started working on the project, I needed to choose a language that
+already had an implementation of a distributed consensus algorithm available.
+That meant [Paxos](https://en.wikipedia.org/wiki/Paxos_(computer_science)) or
+[Raft](https://en.wikipedia.org/wiki/Raft_(computer_science)). Golang was one
+language that actually had two different Raft implementations, `etcd`, and
+`consul`. Other design requirements included something that was reasonably fast,
+typed and memory-safe, and suited for systems engineering. After a reasonably
+extensive search, I chose `golang`. I think it was the right decision. There are
+a number of other features of the language which helped influence the decision.
+
+### How do I contribute to the project if I don't know `golang`?
+
+There are many different ways you can contribute to the project. They can be
+broadly divided into two main categories:
+
+1. With contributions written in `golang`
+2. With contributions _not_ written in `golang`
+
+If you do not know `golang`, and have no desire to learn, you can still
+contribute to mgmt by using it, testing it, writing docs, or even just by
+telling your friends about it. If you don't mind some coding, learning about the
+[mgmt language](https://purpleidea.com/blog/2018/02/05/mgmt-configuration-language/)
+might be an enjoyable experience for you. It is a small [DSL](https://en.wikipedia.org/wiki/Domain-specific_language)
+and not a general purpose programming language, and you might find it more fun
+than what you're typically used to. One of the reasons the mgmt author got into
+writing automation modules, was because he found it much more fun to build with
+a higher level DSL, than in a general purpose programming language.
+
+If you do not know `golang`, and would like to learn, are a beginner and want to
+improve your skills, or want to gain some great interdisciplinary systems
+engineering knowledge around a cool automation project, we're happy to mentor
+you. Here are some pre-requisites steps which we recommend:
+
+1. Make sure you have a somewhat recent GNU/Linux environment to hack on. A
+recent [Fedora](https://getfedora.org/) or [Debian](https://www.debian.org/)
+environment is recommended. Developing, testing, and contributing on `macOS` or
+`Windows` will be either more difficult or impossible.
+2. Ensure that you're mildly comfortable with the basics of using `git`. You can
+find a number of tutorials online.
+3. Spend between four to six hours with the [golang tour](https://tour.golang.org/).
+Skip over the longer problems, but try and get a solid overview of everything.
+If you forget something, you can always go back and repeat those parts.
+4. Connect to our [#mgmtconfig](https://matrix.to/#/#mgmtconfig:matrix.org)
+Matrix channel and hang out with us there out there.
+5. Now it's time to try and starting writing a patch! We have tagged a bunch of
+[open issues as #mgmtlove](https://github.com/purpleidea/mgmt/issues?q=is%3Aissue+is%3Aopen+label%3Amgmtlove)
+for new users to have somewhere to get involved. Look through them to see if
+something interests you. If you find one, let us know you're working on it by
+leaving a comment in the ticket. We'll be around to answer questions in the
+channel, and to create new issues if there wasn't something that fit your
+interests. When you submit a patch, we'll review it and give you some feedback.
+Over time, we hope you'll learn a lot while supporting the project! Now get
+hacking!
+
+### Is this project ready for production?
+
+It's getting pretty close. I'm able to write modules for it now!
+
+Compared to some existing automation tools out there, mgmt is a relatively new
+project. It is probably not as feature complete as some other software, but it
+also offers a number of features which are not currently available elsewhere.
+
+Because we have not released a `1.0` release yet, we are not guaranteeing
+stability of the internal or external API's. We only change them if it's really
+necessary, and we don't expect anything particularly drastic to occur. We would
+expect it to be relatively easy to adapt your code if such changes happened.
+
+As with all software, bugs can occur, and while we make no guarantees of being
+bug-free, there are a number of things we've done to reduce the chances of one
+causing you trouble:
+
+1. Our software is written in golang, which is a memory-safe language, and which
+is known to reduce or eliminate entire classes of bugs.
+2. We have a test suite which we run on every commit, and every 24 hours. If you
+have a particular case that you'd like to test, you are welcome to add it in!
+3. The mgmt language itself offers a number of safety features. You can
+[read about them in the introductory blog post](https://purpleidea.com/blog/2018/02/05/mgmt-configuration-language/).
+
+Having said all this, as with all software, there are still missing features
+which some users might want in their production environments. We're working hard
+to get all of those implemented, but we hope that you'll get involved and help
+us finish off the ones that are most important to you. We are happy to mentor
+new contributors, and have even [tagged](https://github.com/purpleidea/mgmt/issues?q=is%3Aissue+is%3Aopen+label%3Amgmtlove)
+a number of issues if you need help getting started.
+
+Some of the current limitations include:
+
+* Auth hasn't been implemented yet, so you should only use it in trusted
+environments (not on publicly accessible networks) for now.
+* The number of built-in core functions is still small. You may encounter
+scenarios where you're missing a function. The good news is that it's relatively
+easy to add this missing functionality yourself. In time, with your help, the
+list will grow!
+* Large file distribution is not yet implemented. You might want a scenario
+where mgmt is used to distribute large files (such as `.iso` images) throughout
+your cluster. While this isn't a common use-case, it won't be possible until
+someone wants to write the patch. (Mentoring available!) You can workaround this
+easily by storing those files on a separate fileserver for the interim.
+* There isn't an ecosystem of community `modules` yet. We've got this on our
+roadmap, so please stay tuned!
+
+We hope you'll participate as an early adopter. Every additional pair of helping
+hands gets us all there faster! It's quite possible to use this to build useful
+automation today, and we hope you'll start getting familiar with the software.
+
+### Why did you use etcd? What about consul?
+
+Etcd and consul are both written in golang, which made them the top two
+contenders for my prototype. Ultimately a choice had to be made, and etcd was
+chosen, but it was also somewhat arbitrary. If there is available interest,
+good reasoning, *and* patches, then we would consider either switching or
+supporting both, but this is not a high priority at this time.
+
+### Can I use an existing etcd cluster instead of the automatic embedded servers?
+
+Yes, it's possible to use an existing etcd cluster instead of the automatic,
+elastic embedded etcd servers. To do so, simply point to the cluster with the
+`--seeds` variable, the same way you would if you were seeding a new member to
+an existing mgmt cluster.
+
+The downside to this approach is that you won't benefit from the automatic
+elastic nature of the embedded etcd servers, and that you're responsible if you
+accidentally break your etcd cluster, or if you use an unsupported version.
+
+### In `mgmt` you talk about events. What is this referring to?
+
+Mgmt has two main concepts that involve "events":
+1. Events in the [resource primitive](resource-guide.md).
+2. Events in the [reactive language](language-guide.md).
+
+Each resource primitive in mgmt can test (check) and set (apply) the desired
+state that was requested of it. This is familiar to what is common with existing
+tools such as `Puppet`, `Ansible`, `Chef`, `Terraform`, etc... In addition,
+`mgmt` can also **watch** the state and detect changes. As a result, it never
+has to waste time and cpu resources by polling to test and set state, leading to
+a design which is algorithmically much faster than the existing generation of
+tools.
+
+To describe the set of resources to apply, mgmt describes this collection with a
+language. In order to model the time component of infrastructure, we use a
+special kind of language called an [FRP](https://en.wikipedia.org/wiki/Functional_reactive_programming).
+This language has a built-in concept that we call "events", and which means that
+we re-evaluate the relevant portions of the code whenever a value or function
+has an event that tells us that it changed. The `R` in `FRP` stands for
+reactive. This is similar to how a spreadsheet updates dependent cells when a
+pre-requisite value is modified. [This article](https://en.wikipedia.org/wiki/Reactive_programming)
+provides a bit more background.
+
+Whenever any of the streams of values in the language change, the program is
+partially re-evaluated. The output of any mgmt program is a [DAG](https://en.wikipedia.org/wiki/Directed_acyclic_graph)
+of resources, or more precisely, a stream of resource graphs. Since we have
+events per-resource, we can efficiently switch from one desired-state resource
+graph to the next without re-checking their individual states, since we've been
+monitoring them all along.
+
+One side-effect of all this, is that if a rogue systems administrator manually
+changes the state of any managed resource, mgmt will detect this and attempt to
+revert the change. This makes for excellent live demos, but is not the primary
+design goal. It is a consequence of tracking state so that graph changes are
+efficient. We implement the event detection via an intentional per-resource
+[main loop](https://en.wikipedia.org/wiki/Event_loop) which can enable other
+interesting functionality too!
+
+Make sure to get rid of your rogue sysadmin! ;)
+
+### Do I need to run `mgmt` as `root`?
+
+No and yes. It depends. Nothing in mgmt explicitly requires root in the design,
+however mgmt will require root only if the changes to your system that you want
+it to make require root.
+
+For example, if you use it to manage files that require root access to modify,
+then you'll need root. If you only use it to manage files and resources
+elsewhere, then it shouldn't need root. Many resources are perfectly usable
+without root, and virtually all of my live demos are done without root.
+
+### How can I run `mgmt` on-demand, or in `cron`, instead of continuously?
+
+By default, `mgmt` will run continuously in an attempt to keep your machine in a
+converged state, even as external forces change the current state, or as your
+time-varying desired state changes over time. (You can write code in the mgmt
+language which will let you describe a desired state which might change over
+time.)
+
+Some users might prefer to only run `mgmt` on-demand manually, or at a set
+interval via a tool like `cron`. In order to do so, `mgmt` must have a way to
+shut itself down after a single "run". This feature is possible with the
+`--converged-timeout` flag. You may specify this flag, along with a number of
+seconds as the argument, and when there has been no activity for that many
+seconds, the program will shutdown.
+
+Alternatively, while it is not recommended, if you'd like to ensure the program
+never runs for longer that a specific number of seconds, you can ask it to
+shutdown after that time interval using the `--max-runtime` flag. This also
+requires a number of seconds as an argument.
+
+#### Example:
+
+```
+./mgmt run lang examples/lang/hello0.mcl --converged-timeout=5
+```
+
+### Can I run `mgmt` for type-checking only?
+
+Yes, you can, add the `--only-unify` option to the lang frontend while using the
+`run` command, and it will exit after type unification.
+
+#### Example:
+
+```
+./mgmt run --tmp-prefix lang --only-unify examples/lang/hello0.mcl
+```
+
+It will also print how long it took on either success or failure. Keep in mind
+that even if you pass type unification, an `mgmt` run can still fail later on
+for other reasons, although these are mostly runtime considerations.
+
+### Why is type unification happening twice with `mgmt run`?
+
+When you use the `run` action, it runs all of the compile time checks (including
+type unification) that are possible, and then packages everything up into a
+deployable object and runs the same mechanism that `mgmt deploy` uses, sending
+the deploy to itself. At this point, mgmt starts up as a server, and receives
+the deploy. It will then need to run type unification again before running the
+code.
+
+You can skip the first type unification check by adding the `--skip-unify`
+option to the lang frontend when using the `run` command.
+
+You can also skip this check when running the `deploy` action, but if your code
+doesn't pass, you might be deploying broken code. This is not recommended.
+
+#### Example:
+
+```
+./mgmt run --tmp-prefix lang --skip-unify examples/lang/hello0.mcl
+```
+
+### Why does my file resource error with `no such file or directory`?
+
+If you create a file resource and only specify the content like this:
+
+```
+file "/tmp/foo" {
+	content => "hello world\n",
+}
+```
+
+Then this will attempt to set the contents of that file to the desired string,
+but *only* if that file already exists. If you'd like to ensure that it also
+gets created in case it is not present, then you must also specify the state:
+
+```
+file "/tmp/foo" {
+	state => $const.res.file.state.exists,
+	content => "hello world\n",
+}
+```
+
+Similar logic applies for situations when you only specify the `mode` parameter.
+
+This all turns out to be more safe and "correct", in that it would error and
+prevent masking an error for a situation when you expected a file to already be
+at that location. It also turns out to simplify the internals significantly, and
+remove an ambiguous scenario with the reversible file resource.
+
+### Package resources error with: "The name is not activatable", what's wrong?
+
+You may see an error like:
+
+`main: error running auto edges: The name is not activatable`
+
+This can happen because the mgmt `pkg` resource uses a library and daemon called
+`PackageKit` to install packages. If it is not installed, then it cannot do its
+work. On Fedora system you may wish to run `dnf install /usr/bin/pkcon` or on a
+Debian system you may wish to run `apt install packagekit-tools`.
+
+PackageKit is excellent because it provides both an API and an event system to
+watch the package database for changes, and it abstracts away the differences
+between the various package managers. If you'd prefer to not need to install
+this tool, then you can contribute a native `pkg:rpm` and `pkg:deb` resource to
+mgmt!
+
+### When running mgmt, it says: "module path error: can't find a module path".
+
+You might get an error along the lines of:
+
+```
+could not set scope: import scope `git://github.com/purpleidea/mgmt/modules/some_module_name/` failed: module path error: can't find a module path
+```
+
+This usually means that you haven't specified the directory that mgmt should use
+when looking for modules. This could happen when using mgmt interactively or
+when it's being run as a service. In such cases you may want the main invocation
+to look something like:
+
+```
+mgmt run lang --module-path '/etc/mgmt/modules/' /etc/mgmt/main.mcl
+```
+
+### I get an error: "cannot open shared object file: No such file or directory".
+
+Mgmt currently uses two libraries that depend on `.so` files being installed on
+the host. Those are for `augeas` and `libvirt`. If those dependencies are not
+present, then mgmt will not run. The complete error might look like:
+
+```
+mgmt: error while loading shared libraries: libvirt-lxc.so.0: cannot open shared object file: No such file or directory
+```
+
+or:
+
+```
+mgmt: error while loading shared libraries: libaugeas.so.0: cannot open shared object file: No such file or directory
+```
+
+or something similar. There are two solutions to this:
+
+1. Use a build that doesn't include one or both of those features. You can build
+that like: `GOTAGS="noaugeas novirt nodocker" make build`.
+
+2. Install those dependencies. On a Fedora machine you might want to run:
+
+```
+dnf install libvirt-devel augeas-devel
+```
+
+On a Debian machine you might want to run:
+
+```
+apt install libvirt-dev libaugeas-dev
+```
+
+### Why do function names inside of templates include underscores?
+
+The golang template library which we use to implement the golang.template() func
+doesn't support the dot notation, so we import all our normal functions, and
+just replace dots with underscores. As an example, the standard `datetime.print`
+function is shown within mcl scripts as datetime_print after being imported.
+
+### On startup `mgmt` hangs after: `etcd: server: starting...`.
+
+If you get an error message similar to:
+
+```
+etcd: server: starting...
+etcd: server: start timeout of 1m0s reached
+etcd: server: close timeout of 15s reached
+```
+
+But nothing happens afterwards, this can be due to a corrupt etcd storage
+directory. Each etcd server embedded in mgmt must have a special directory where
+it stores local state. It must not be shared by more than one individual member.
+This dir is typically `/var/lib/mgmt/etcd/member/`. If you accidentally use it
+(for example during testing) with a different cluster view, then you can corrupt
+it. This can happen if you use it with more than one different hostname.
+
+The solution is to avoid making this mistake, and if there is no important data
+saved, you can remove the etcd member dir and start over.
+
+### On running `make` to build a new version, it errors with: `Text file busy`.
+
+If you get an error like:
+
+```
+cp: cannot create regular file 'mgmt': Text file busy
+```
+
+This can happen if you ran `make build` (or just `make`) when there was already
+an instance of mgmt running, or if a related file locking issue occurred. To
+solve this, shutdown and running mgmt process, run `rm mgmt` to remove the file,
+and then get a new one by running `make` again.
+
+### Type unification error with string interpolation.
+
+Look carefully at the following code:
+
+```
+$num = 42
+print "hello" {
+	msg => "My favourite number is ${num}",
+}
+```
+
+What's actually happening is that we can't unify `str + int`, because our
+addition operator only supports `str + str`, `int + int`, and `float + float`.
+The string interpolation feature can only combine strings. One solution is to
+instead write:
+
+```
+$num = "42" # now this is a string
+print "hello" {
+	msg => "My favourite number is ${num}",
+}
+```
+
+The first example will usually error with something along the lines of:
+
+`unify error with: topLevel(func() { <built-in:concat> }): type error: int != str`
+
+Now you know why this specific case doesn't work! We may reconsider allowing
+other types to be pulled into interpolation in the future. If you have a good
+case for this, then let us know.
+
+### The run and deploy commands don't parse correctly when used with `--seeds`.
+
+If you're running a command with `--seeds`, `--server-urls`, or `--client-urls`,
+then make sure you are using an equals sign between the flag name and the value.
+For example, if you were to run:
+
+```
+# wrong invocation!
+mgmt deploy --no-git --seeds http://127.0.0.1:2379 lang code/test.mcl
+```
+
+Then the `--seeds` flag would interpret `lang` and `code/test.mcl` as additional
+seeds. This flag as well as the other aforementioned ones all accept multiple
+values. Use an equals sign to guarantee you enter the correct data, eg:
+
+```
+# better invocation! (note the equals sign)
+mgmt deploy --no-git --seeds=http://127.0.0.1:2379 lang code/test.mcl
+```
+
+This is caused by a parsing peculiarity of the CLI library that we are using.
+This is tracked upstream at: [https://github.com/alexflint/go-arg/issues/239](https://github.com/alexflint/go-arg/issues/239).
+We have a workaround in place to mitigate it and attempt to show you a helpful
+error message, but it's also documented here in the meantime. The error you will
+see is: `cli parse error: missing equals sign for list element`.
+
+### The docs speaks of `--remote` but the CLI errors out?
+
+The `--remote` flag existed in an earlier version of mgmt. It was removed and
+will be replaced with a more powerful version, which is a "remote" resource. The
+code is mostly ready but it's not finished. If you'd like to help finish it or
+sponsor the work, please let me know.
+
+### Does this support Windows? OSX? GNU Hurd?
+
+Mgmt probably works best on Linux, because that's what most developers use for
+serious automation workloads. Support for non-Linux operating systems isn't a
+high priority of mine, but we're happy to accept patches for missing features
+or resources that you think would make sense on your favourite platform.
+
+### Why aren't you using `glide`, `godep` or `go mod` for dependency management?
+
+Vendoring dependencies means that as the git master branch of each dependency
+marches on, you're left behind using an old version. As a result, bug fixes and
+improvements are not automatically brought into the project. Instead, we run our
+complete test suite against the entire project (with the latest dependencies)
+[every 24 hours](https://docs.travis-ci.com/user/cron-jobs/) to ensure that it
+all still works.
+
+Occasionally a dependency breaks API and causes a failure. In those situations,
+we're notified almost immediately, it's easy to see exactly which commit caused
+the breakage, and we can either quickly notify the author (if it was a mistake)
+or update our code if it was a sensible change. This also puts less burden on
+authors to support old, legacy versions of their software unnecessarily.
+
+Historically, we've had approximately one such breakage per year, which were all
+detected and fixed within a few hours. The cost of these small, rare,
+interruptions is much less expensive than having to periodically move every
+dependency in the project to the latest versions. Some examples of this include:
+
+* We caught the `go-bindata` swap before it was publicly known, and fixed it in:
+[adbe9c7be178898de3645b0ed17ed2ca06646017](https://github.com/purpleidea/mgmt/commit/adbe9c7be178898de3645b0ed17ed2ca06646017).
+
+* We caught the `codegangsta/cli` API change improvement, and fixed it in:
+[ab73261fd4e98cf7ecb08066ad228a8f559ba16a](https://github.com/purpleidea/mgmt/commit/ab73261fd4e98cf7ecb08066ad228a8f559ba16a).
+
+* We caught an un-announced libvirt API change, and promptly fixed it in:
+[95cb94a03958a9d2ebf01df0821a8c13a4f3a28c](https://github.com/purpleidea/mgmt/commit/95cb94a03958a9d2ebf01df0821a8c13a4f3a28c).
+
+If we choose responsible dependencies, then it usually means that those authors
+are also responsible with their changes to API and to git master. If we ever
+find that it's not the case, then we will either switch that dependency to a
+more responsible version, or fork it if necessary.
+
+Occasionally, we want to pin a dependency to a particular version. This can
+happen if the project treats `git master` as an unstable branch, or because a
+dependency needs a newer version of golang than the minimum that we require for
+our project. In those cases it's sensible to assume the technical debt, and
+vendor the dependency. The common tools such as `glide` and `godep` work by
+requiring you install their software, and by either storing a yaml file with the
+version of that dependency in your repository, and/or copying all of that code
+into git and explicitly storing it. This project thinks that all of these
+solutions are wasteful and unnecessary, particularly when an existing elegant
+solution already exists: `[git submodules](https://git-scm.com/book/en/v2/Git-Tools-Submodules)`.
+
+The advantages of using `git submodules` are three-fold:
+1. You already have the required tools installed.
+2. You only store a pointer to the dependency, not additional files or code.
+3. The git submodule tools let you easily switch dependency versions, see diff
+output, and responsibly plan and test your versions bumps with ease.
+
+Don't blindly use the tools that others tell you to. Learn what they do, think
+for yourself, and become a power user today! That process led us to using
+`git submodules`. Hopefully you'll come to the same conclusions that we did.
+
+**UPDATE:**
+
+After golang made it virtually impossible to build without `go.mod` stuff, we've
+switched to it since golang 1.16. I still think the above approach was better,
+and that the `go mod` tooling should have been a layer on top of git submodules
+so that we don't grow yet another lock file format, and existing folks who are
+comfortable with `git` can use those tools directly.
+
+### Did you know that there is a band named `MGMT`?
+
+I didn't realize this when naming the project, and it is accidental. After much
+anguishing, I chose the name because it was short and I thought it was
+appropriately descriptive. If you need a less ambiguous search term or phrase,
+you can try using `mgmtconfig` or `mgmt config`.
+
+It also doesn't stand for
+[Methyl Guanine Methyl Transferase](https://en.wikipedia.org/wiki/O-6-methylguanine-DNA_methyltransferase)
+which definitely existed before the band did.
+
+### You didn't answer my question, or I have a question!
+
+It's best to ask on [Matrix](https://matrix.to/#/#mgmtconfig:matrix.org) to see
+if someone can help. If you don't get a response there, you can send a patch to
+this documentation. I'll merge your question, and add a patch with the answer!
+For news and updates, subscribe to the [mailing list](https://www.redhat.com/mailman/listinfo/mgmtconfig-list).

docs/function-guide.md

@@ -0,0 +1,361 @@
+# Function guide
+
+## Overview
+
+The `mgmt` tool has built-in functions which add useful, reactive functionality
+to the language. This guide describes the different function API's that are
+available. It is meant to instruct developers on how to write new functions.
+Since `mgmt` and the core functions are written in golang, some prior golang
+knowledge is assumed.
+
+## Theory
+
+Functions in `mgmt` are similar to functions in other languages, however they
+also have a [reactive](https://en.wikipedia.org/wiki/Functional_reactive_programming)
+component. Our functions can produce events over time, and there are different
+ways to write functions. For some background on this design, please read the
+[original article](https://purpleidea.com/blog/2018/02/05/mgmt-configuration-language/)
+on the subject.
+
+## Native Functions
+
+Native functions are functions which are implemented in the mgmt language
+itself. These are currently not available yet, but are coming soon. Stay tuned!
+
+## Simple Function API
+
+Most functions should be implemented using the simple function API. This API
+allows you to implement simple, static, [pure](https://en.wikipedia.org/wiki/Pure_function)
+functions that don't require you to write much boilerplate code. They will be
+automatically re-evaluated as needed when their input values change. These will
+all be automatically made available as helper functions within mgmt templates,
+and are also available for use anywhere inside mgmt programs.
+
+You'll need some basic knowledge of using the [`types`](https://github.com/purpleidea/mgmt/tree/master/lang/types)
+library which is included with mgmt. This library lets you interact with the
+available types and values in the mgmt language. It is very easy to use, and
+should be fairly intuitive. Most of what you'll need to know can be inferred
+from looking at example code.
+
+To implement a function, you'll need to create a file that imports the
+[`lang/funcs/simple/`](https://github.com/purpleidea/mgmt/tree/master/lang/funcs/simple/)
+module. It should probably get created in the correct directory inside of:
+[`lang/core/`](https://github.com/purpleidea/mgmt/tree/master/lang/core/). The
+function should be implemented as a `simple.Scaffold` in our API. It is then
+registered with the engine during `init()`. An example explains it best:
+
+### Example
+
+```golang
+package simple
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/purpleidea/mgmt/lang/funcs/simple"
+	"github.com/purpleidea/mgmt/lang/types"
+)
+
+// you must register your functions in init when the program starts up
+func init() {
+	// Example function that squares an int and prints out answer as an str.
+
+	simple.ModuleRegister(ModuleName, "talkingsquare", &simple.Scaffold{
+		T: types.NewType("func(int) str"), // declare the signature
+		F: func(ctx context.Context, input []types.Value) (types.Value, error) {
+			i := input[0].Int() // get first arg as an int64
+			// must return the above specified value
+			return &types.StrValue{
+				V: fmt.Sprintf("%d^2 is %d", i, i * i),
+			}, nil // no serious errors occurred
+		},
+	})
+}
+```
+
+This simple function accepts one `int` as input, and returns one `str`.
+Functions can have zero or more inputs, and must have exactly one output. You
+must be sure to use the `types` library correctly, since if you try and access
+an input which should not exist (eg: `input[2]`, when there are only two
+that are expected), then you will cause a panic. If you have declared that a
+particular argument is an `int` but you try to read it with `.Bool()` you will
+also cause a panic. Lastly, make sure that you return a value in the correct
+type or you will also cause a panic!
+
+If anything goes wrong, you can return an error, however this will cause the
+mgmt engine to shutdown. It should be seen as the equivalent to calling a
+`panic()`, however it is safer because it brings the engine down cleanly.
+Ideally, your functions should never need to error. You should never cause a
+real `panic()`, since this could have negative consequences to the system.
+
+### Example
+
+```golang
+package simple
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/purpleidea/mgmt/lang/funcs/simple"
+	"github.com/purpleidea/mgmt/lang/types"
+)
+
+func init() {
+	// This is the actual definition of the `len` function.
+	simple.Register("len", &simple.Scaffold{
+		T: types.NewType("func(?1) int"), // contains a unification var
+		C: simple.TypeMatch([]string{     // match on any of these sigs
+			"func(str) int",
+			"func([]?1) int",
+			"func(map{?1: ?2}) int",
+		}),
+		// The implementation is left as an exercise for the reader.
+		F: Len,
+	})
+}
+```
+
+## Simple Polymorphic Function API
+
+Most functions should be implemented using the simple function API. If they need
+to have multiple polymorphic forms under the same name, with each resultant type
+match needing to be paired to a different implementation, then you can use this
+API. This is useful for situations when the functions differ in output type
+only.
+
+## Function API
+
+To implement a reactive function in `mgmt` it must satisfy the
+[`Func`](https://github.com/purpleidea/mgmt/blob/master/lang/interfaces/func.go)
+interface. Using the [Simple Function API](#simple-function-api) is preferable
+if it meets your needs. Most functions will be able to use that API. If you
+really need something more powerful, then you can use the regular function API.
+What follows are each of the method signatures and a description of each.
+
+### Info
+
+```golang
+Info() *interfaces.Info
+```
+
+This returns some information about the function. It is necessary so that the
+compiler can type check the code correctly, and know what optimizations can be
+performed. This is usually the first method which is called by the engine.
+
+#### Example
+
+```golang
+func (obj *FooFunc) Info() *interfaces.Info {
+	return &interfaces.Info{
+		Pure: true,
+		Sig:  types.NewType("func(a int) str"),
+	}
+}
+```
+
+### Init
+
+```golang
+Init(init *interfaces.Init) error
+```
+
+This is called to initialize the function. If something goes wrong, it should
+return an error. It is passed a struct that contains all the important
+information and pointers that it might need to work with throughout its
+lifetime. As a result, it will need to save a copy to that pointer for future
+use in the other methods.
+
+#### Example
+
+```golang
+// Init runs some startup code for this function.
+func (obj *FooFunc) Init(init *interfaces.Init) error {
+	obj.init = init
+	return nil
+}
+```
+
+### Call
+
+Call is run when you want to return a new value from the function. It takes the
+input arguments to the function.
+
+#### Example
+
+```golang
+func (obj *FooFunc) Call(ctx context.Context, args []types.Value) (types.Value, error) {
+	return &types.StrValue{ // Our type system "str" (string) value.
+		V: strconv.FormatInt(args[0].Int(), 10), // a golang string
+	}, nil
+}
+```
+
+### Stream
+
+```golang
+Stream(context.Context) error
+```
+
+`Stream` is where any evented work is done. This method is started by the
+function engine. It will run this function once. It should call the
+`obj.init.Event()` method when it believes the function engine should run
+`Call()` again.
+
+Implementing this is not required if you don't have events.
+
+If the `ctx` closes, you must shutdown as soon as possible.
+
+#### Example
+
+```golang
+// Stream starts a mainloop and runs Event when it's time to Call() again.
+func (obj *FooFunc) Stream(ctx context.Context) error {
+
+	ticker := time.NewTicker(time.Duration(1) * time.Second)
+	defer ticker.Stop()
+
+	// streams must generate an initial event on startup
+	// even though ticker will send one, we want to be faster to first event
+	startChan := make(chan struct{}) // start signal
+	close(startChan)                 // kick it off!
+
+	for {
+		select {
+		case <-startChan:
+			startChan = nil // disable
+
+		case <-ticker.C: // received the timer event
+			// pass
+
+		case <-ctx.Done():
+			return nil
+		}
+
+		if err := obj.init.Event(ctx); err != nil {
+			return err
+		}
+	}
+}
+```
+
+## Further considerations
+
+There is some additional information that any function author will need to know.
+Each issue is listed separately below!
+
+### Function struct
+
+Each function will implement methods as pointer receivers on a function struct.
+The naming convention for resources is that they end with a `Func` suffix.
+
+#### Example
+
+```golang
+type FooFunc struct {
+	init *interfaces.Init
+
+	// this space can be used if needed
+}
+```
+
+### Function registration
+
+All functions must be registered with the engine so that they can be found. This
+also ensures they can be encoded and decoded. Make sure to include the following
+code snippet for this to work.
+
+```golang
+import "github.com/purpleidea/mgmt/lang/funcs"
+
+func init() { // special golang method that runs once
+	funcs.Register("foo", func() interfaces.Func { return &FooFunc{} })
+}
+```
+
+Functions inside of built-in modules will need to use the `ModuleRegister`
+method instead.
+
+```golang
+// moduleName is already set to "math" by the math package. Do this in `init`.
+funcs.ModuleRegister(moduleName, "cos", func() interfaces.Func {
+	return &CosFunc{}
+})
+```
+
+### Composite functions
+
+Composite functions are functions which import one or more existing functions.
+This is useful to prevent code duplication in higher level function scenarios.
+Unfortunately no further documentation about this subject has been written. To
+expand this section, please send a patch! Please contact us if you'd like to
+work on a function that uses this feature, or to add it to an existing one!
+We don't expect this functionality to be particularly useful or common, as it's
+probably easier and preferable to simply import common golang library code into
+multiple different functions instead.
+
+## Frequently asked questions
+
+(Send your questions as a patch to this FAQ! I'll review it, merge it, and
+respond by commit with the answer.)
+
+### Can I use global variables?
+
+Probably not. You must assume that multiple copies of your function may be used
+at the same time. If they require a global variable, it's likely this won't
+work. Instead it's probably better to use a struct local variable if you need to
+store some state.
+
+There might be some rare instances where a global would be acceptable, but if
+you need one of these, you're probably already an internals expert. If you think
+they need to lock or synchronize so as to not overwhelm an external resource,
+then you have to be especially careful not to cause deadlocking the mgmt engine.
+
+### Can I write functions in a different language?
+
+Currently `golang` is the only supported language for built-in functions. We
+might consider allowing external functions to be imported in the future. This
+will likely require a language that can expose a C-like API, such as `python` or
+`ruby`. Custom `golang` functions are already possible when using mgmt as a lib.
+
+### What new functions need writing?
+
+There are still many ideas for new functions that haven't been written yet. If
+you'd like to contribute one, please contact us and tell us about your idea!
+
+### Can I generate many different `FuncValue` implementations from one function?
+
+Yes, you can use a function generator in `golang` to build multiple different
+implementations from the same function generator. You just need to implement a
+function which *returns* a `golang` type of `func([]types.Value) (types.Value, error)`
+which is what `FuncValue` expects. The generator function can use any input it
+wants to build the individual functions, thus helping with code reuse.
+
+### How do I determine the signature of my simple, polymorphic function?
+
+The determination of the input portion of the function signature can be
+determined by inspecting the length of the input, and the specific type each
+value has. Length is done in the standard `golang` way, and the type of each
+element can be ascertained with the `Type()` method available on every value.
+
+Knowing the output type is trickier. If it can not be inferred in some manner,
+then the only way is to keep track of this yourself. You can use a function
+generator to build your `FuncValue` implementations, and pass in the unique
+signature to each one as you are building them. Using a generator is a common
+technique which was mentioned previously.
+
+One obvious situation where this might occur is if your function doesn't take
+any inputs! An example `math.fortytwo()` function was implemented that
+demonstrates the use of function generators to pass the type signatures into the
+implementations.
+
+### Where can I find more information about mgmt?
+
+Additional blog posts, videos and other material [is available!](https://github.com/purpleidea/mgmt/blob/master/docs/on-the-web.md).
+
+## Suggestions
+
+If you have any ideas for API changes or other improvements to function writing,
+please let us know! We're still pre 1.0 and pre 0.1 and happy to break API in
+order to get it right!

docs/generate.go

@@ -0,0 +1,795 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+package docs
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	cliUtil "github.com/purpleidea/mgmt/cli/util"
+	docsUtil "github.com/purpleidea/mgmt/docs/util"
+	"github.com/purpleidea/mgmt/engine"
+	engineUtil "github.com/purpleidea/mgmt/engine/util"
+	"github.com/purpleidea/mgmt/lang/funcs"
+	"github.com/purpleidea/mgmt/lang/interfaces"
+	"github.com/purpleidea/mgmt/util"
+)
+
+const (
+	// JSONSuffix is the output extension for the generated documentation.
+	JSONSuffix = ".json"
+)
+
+// Generate is the main entrypoint for this command. It generates everything.
+type Generate struct {
+	*cliUtil.DocsGenerateArgs // embedded config
+	Config                    // embedded Config
+
+	// Program is the name of this program, usually set at compile time.
+	Program string
+
+	// Version is the version of this program, usually set at compile time.
+	Version string
+
+	// Debug represents if we're running in debug mode or not.
+	Debug bool
+
+	// Logf is a logger which should be used.
+	Logf func(format string, v ...interface{})
+}
+
+// Main runs everything for this setup item.
+func (obj *Generate) Main(ctx context.Context) error {
+	if err := obj.Validate(); err != nil {
+		return err
+	}
+
+	if err := obj.Run(ctx); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Validate verifies that the structure has acceptable data stored within.
+func (obj *Generate) Validate() error {
+	if obj == nil {
+		return fmt.Errorf("data is nil")
+	}
+	if obj.Program == "" {
+		return fmt.Errorf("program is empty")
+	}
+	if obj.Version == "" {
+		return fmt.Errorf("version is empty")
+	}
+
+	return nil
+}
+
+// Run performs the desired actions to generate the documentation.
+func (obj *Generate) Run(ctx context.Context) error {
+
+	outputFile := obj.DocsGenerateArgs.Output
+	if outputFile == "" || !strings.HasSuffix(outputFile, JSONSuffix) {
+		return fmt.Errorf("must specify output")
+	}
+	// support relative paths too!
+	if !strings.HasPrefix(outputFile, "/") {
+		wd, err := os.Getwd()
+		if err != nil {
+			return err
+		}
+		outputFile = filepath.Join(wd, outputFile)
+	}
+
+	if obj.Debug {
+		obj.Logf("output: %s", outputFile)
+	}
+
+	// Ensure the directory exists.
+	//d := filepath.Dir(outputFile)
+	//if err := os.MkdirAll(d, 0750); err != nil {
+	//	return fmt.Errorf("could not make output dir at: %s", d)
+	//}
+
+	resources, err := obj.genResources()
+	if err != nil {
+		return err
+	}
+
+	functions, err := obj.genFunctions()
+	if err != nil {
+		return err
+	}
+
+	data := &Output{
+		Version:   safeVersion(obj.Version),
+		Resources: resources,
+		Functions: functions,
+	}
+
+	b, err := json.Marshal(data)
+	if err != nil {
+		return err
+	}
+	b = append(b, '\n') // needs a trailing newline
+
+	if err := os.WriteFile(outputFile, b, 0600); err != nil {
+		return err
+	}
+	obj.Logf("wrote: %s", outputFile)
+
+	return nil
+}
+
+func (obj *Generate) getResourceInfo(kind, filename, structName string) (*ResourceInfo, error) {
+	rootDir := obj.DocsGenerateArgs.RootDir
+	if rootDir == "" {
+		wd, err := os.Getwd()
+		if err != nil {
+			return nil, err
+		}
+		rootDir = wd + "/" // add a trailing slash
+	}
+	if !strings.HasPrefix(rootDir, "/") || !strings.HasSuffix(rootDir, "/") {
+		return nil, fmt.Errorf("bad root dir: %s", rootDir)
+	}
+
+	// filename might be "noop.go" for example
+	p := filepath.Join(rootDir, engine.ResourcesRelDir, filename)
+
+	fset := token.NewFileSet()
+
+	// f is a: https://golang.org/pkg/go/ast/#File
+	f, err := parser.ParseFile(fset, p, nil, parser.ParseComments)
+	if err != nil {
+		return nil, err
+	}
+
+	// mcl field name to golang field name
+	mapping, err := engineUtil.LangFieldNameToStructFieldName(kind)
+	if err != nil {
+		return nil, err
+	}
+	// golang field name to mcl field name
+	nameMap, err := util.MapSwap(mapping)
+	if err != nil {
+		return nil, err
+	}
+	// mcl field name to mcl type
+	typMap, err := engineUtil.LangFieldNameToStructType(kind)
+	if err != nil {
+		return nil, err
+	}
+
+	ri := &ResourceInfo{}
+	// Populate the fields, even if they don't have a comment.
+	ri.Name = structName // golang name
+	ri.Kind = kind       // duplicate data
+	ri.File = filename
+	ri.Fields = make(map[string]*ResourceFieldInfo)
+	for mclFieldName, fieldName := range mapping {
+		typ, exists := typMap[mclFieldName]
+		if !exists {
+			continue
+		}
+
+		ri.Fields[mclFieldName] = &ResourceFieldInfo{
+			Name: fieldName,
+			Type: typ.String(),
+			Desc: "", // empty for now
+		}
+	}
+
+	var previousComment *ast.CommentGroup
+
+	// Walk through the AST...
+	ast.Inspect(f, func(node ast.Node) bool {
+
+		// Comments above the struct appear as a node right _before_ we
+		// find the struct, so if we see one, save it for later...
+		if cg, ok := node.(*ast.CommentGroup); ok {
+			previousComment = cg
+			return true
+		}
+
+		typeSpec, ok := node.(*ast.TypeSpec)
+		if !ok {
+			return true
+		}
+		name := typeSpec.Name.Name // name is now known!
+
+		// If the struct isn't what we're expecting, then move on...
+		if name != structName {
+			return true
+		}
+
+		// Check if the TypeSpec is a named struct type that we want...
+		st, ok := typeSpec.Type.(*ast.StructType)
+		if !ok {
+			return true
+		}
+
+		// At this point, we have the struct we want...
+
+		var comment *ast.CommentGroup
+		if typeSpec.Doc != nil {
+			// I don't know how to even get here...
+			comment = typeSpec.Doc // found!
+
+		} else if previousComment != nil {
+			comment = previousComment // found!
+			previousComment = nil
+		}
+
+		ri.Desc = commentCleaner(comment)
+
+		// Iterate over the fields of the struct
+		for _, field := range st.Fields.List {
+			// Check if the field has a comment associated with it
+			if field.Doc == nil {
+				continue
+			}
+
+			if len(field.Names) < 1 { // XXX: why does this happen?
+				continue
+			}
+
+			fieldName := field.Names[0].Name
+			if fieldName == "" { // Can this happen?
+				continue
+			}
+			if isPrivate(fieldName) {
+				continue
+			}
+
+			mclFieldName, exists := nameMap[fieldName]
+			if !exists {
+				continue
+			}
+
+			ri.Fields[mclFieldName].Desc = commentCleaner(field.Doc)
+		}
+
+		return true
+	})
+
+	return ri, nil
+}
+
+func (obj *Generate) genResources() (map[string]*ResourceInfo, error) {
+	resources := make(map[string]*ResourceInfo)
+	if obj.DocsGenerateArgs.NoResources {
+		return resources, nil
+	}
+
+	r := engine.RegisteredResourcesNames()
+	sort.Strings(r)
+	for _, kind := range r {
+		metadata, err := docsUtil.LookupResource(kind)
+		if err != nil {
+			return nil, err
+		}
+
+		if strings.HasPrefix(kind, "_") {
+			// TODO: Should we display these somehow?
+			// built-in resource
+			continue
+		}
+
+		ri, err := obj.getResourceInfo(kind, metadata.Filename, metadata.Typename)
+		if err != nil {
+			return nil, err
+		}
+
+		if ri.Name == "" {
+			return nil, fmt.Errorf("empty resource name: %s", kind)
+		}
+		if ri.File == "" {
+			return nil, fmt.Errorf("empty resource file: %s", kind)
+		}
+		if ri.Desc == "" {
+			obj.Logf("empty resource desc: %s", kind)
+		}
+		fields := []string{}
+		for field := range ri.Fields {
+			fields = append(fields, field)
+		}
+		sort.Strings(fields)
+		for _, field := range fields {
+			if ri.Fields[field].Desc == "" {
+				obj.Logf("empty resource (%s) field desc: %s", kind, field)
+			}
+		}
+
+		resources[kind] = ri
+	}
+
+	return resources, nil
+}
+
+func (obj *Generate) getFunctionInfo(pkg, name string, metadata *docsUtil.Metadata) (*FunctionInfo, error) {
+	rootDir := obj.DocsGenerateArgs.RootDir
+	if rootDir == "" {
+		wd, err := os.Getwd()
+		if err != nil {
+			return nil, err
+		}
+		rootDir = wd + "/" // add a trailing slash
+	}
+	if !strings.HasPrefix(rootDir, "/") || !strings.HasSuffix(rootDir, "/") {
+		return nil, fmt.Errorf("bad root dir: %s", rootDir)
+	}
+	if metadata.Filename == "" {
+		return nil, fmt.Errorf("empty filename for: %s.%s", pkg, name)
+	}
+
+	// filename might be "pow.go" for example and contain a rel dir
+	p := filepath.Join(rootDir, funcs.FunctionsRelDir, metadata.Filename)
+
+	fset := token.NewFileSet()
+
+	// f is a: https://golang.org/pkg/go/ast/#File
+	f, err := parser.ParseFile(fset, p, nil, parser.ParseComments)
+	if err != nil {
+		return nil, err
+	}
+
+	fi := &FunctionInfo{}
+	fi.Name = metadata.Typename
+	fi.File = metadata.Filename
+
+	var previousComment *ast.CommentGroup
+	found := false
+
+	rawFunc := func(node ast.Node) (*ast.CommentGroup, string) {
+		fd, ok := node.(*ast.FuncDecl)
+		if !ok {
+			return nil, ""
+		}
+		return fd.Doc, fd.Name.Name // name is now known!
+	}
+
+	rawStruct := func(node ast.Node) (*ast.CommentGroup, string) {
+		typeSpec, ok := node.(*ast.TypeSpec)
+		if !ok {
+			return nil, ""
+		}
+
+		// Check if the TypeSpec is a named struct type that we want...
+		if _, ok := typeSpec.Type.(*ast.StructType); !ok {
+			return nil, ""
+		}
+
+		return typeSpec.Doc, typeSpec.Name.Name // name is now known!
+	}
+
+	// Walk through the AST...
+	ast.Inspect(f, func(node ast.Node) bool {
+
+		// Comments above the struct appear as a node right _before_ we
+		// find the struct, so if we see one, save it for later...
+		if cg, ok := node.(*ast.CommentGroup); ok {
+			previousComment = cg
+			return true
+		}
+
+		doc, name := rawFunc(node) // First see if it's a raw func.
+		if name == "" {
+			doc, name = rawStruct(node) // Otherwise it's a struct.
+		}
+
+		// If the func isn't what we're expecting, then move on...
+		if name != metadata.Typename {
+			return true
+		}
+
+		var comment *ast.CommentGroup
+		if doc != nil {
+			// I don't know how to even get here...
+			comment = doc // found!
+
+		} else if previousComment != nil {
+			comment = previousComment // found!
+			previousComment = nil
+		}
+
+		fi.Desc = commentCleaner(comment)
+		found = true
+
+		return true
+	})
+
+	if !found {
+		//return nil, nil
+	}
+
+	return fi, nil
+}
+
+func (obj *Generate) genFunctions() (map[string]*FunctionInfo, error) {
+	functions := make(map[string]*FunctionInfo)
+	if obj.DocsGenerateArgs.NoFunctions {
+		return functions, nil
+	}
+
+	m := funcs.Map() // map[string]func() interfaces.Func
+	names := []string{}
+	for name := range m {
+		names = append(names, name)
+	}
+	sort.Slice(names, func(i, j int) bool {
+		a := names[i]
+		b := names[j]
+		// TODO: do a sorted-by-package order.
+		return a < b
+	})
+
+	for _, name := range names {
+		//v := m[name]
+		//fn := v()
+		fn := m[name]()
+
+		// eg: golang/strings.has_suffix
+		sp := strings.Split(name, ".")
+		if len(sp) == 0 {
+			return nil, fmt.Errorf("unexpected empty function")
+		}
+		if len(sp) > 2 {
+			return nil, fmt.Errorf("unexpected function name: %s", name)
+		}
+		n := sp[0]
+		p := sp[0]
+		if len(sp) == 1 { // built-in
+			p = "" // no package!
+		}
+		if len(sp) == 2 { // normal import
+			n = sp[1]
+		}
+
+		if strings.HasPrefix(n, "_") {
+			// TODO: Should we display these somehow?
+			// built-in function
+			continue
+		}
+
+		var sig *string
+		//iface := ""
+		if x := fn.Info().Sig; x != nil {
+			s := x.String()
+			sig = &s
+			//iface = "simple"
+		}
+
+		metadata := &docsUtil.Metadata{}
+
+		// XXX: maybe we need a better way to get this?
+		mdFunc, ok := fn.(interfaces.MetadataFunc)
+		if !ok {
+			// Function doesn't tell us what the data is, let's try
+			// to get it automatically...
+			metadata.Typename = funcs.GetFunctionName(fn) // works!
+			metadata.Filename = ""                        // XXX: How can we get this?
+
+			// XXX: We only need this back-channel metadata store
+			// because we don't know how to get the filename without
+			// manually writing code in each function. Alternatively
+			// we could add a New() method to each struct and then
+			// we could modify the struct instead of having it be
+			// behind a copy which is needed to get new copies!
+			var err error
+			metadata, err = docsUtil.LookupFunction(name)
+			if err != nil {
+				return nil, err
+			}
+
+		} else if mdFunc == nil {
+			// programming error
+			return nil, fmt.Errorf("unexpected empty metadata for function: %s", name)
+
+		} else {
+			metadata = mdFunc.GetMetadata()
+		}
+
+		if metadata == nil {
+			return nil, fmt.Errorf("unexpected nil metadata for function: %s", name)
+		}
+
+		// This may be an empty func name if the function did not know
+		// how to get it. (This is normal for automatic regular funcs.)
+		if metadata.Typename == "" {
+			metadata.Typename = funcs.GetFunctionName(fn) // works!
+		}
+
+		fi, err := obj.getFunctionInfo(p, n, metadata)
+		if err != nil {
+			return nil, err
+		}
+		// We may not get any fields added if we can't find anything...
+		fi.Name = metadata.Typename
+		fi.Package = p
+		fi.Func = n
+		fi.File = metadata.Filename
+		//fi.Desc = desc
+		fi.Signature = sig
+
+		// Hack for golang generated functions!
+		if strings.HasPrefix(fi.Package, "golang/") && fi.File == "generated_funcs.go" {
+			pkg := fi.Package[len("golang/"):]
+			frag := strings.TrimPrefix(fi.Name, strings.Title(strings.Join(strings.Split(pkg, "/"), ""))) // yuck
+			fi.File = fmt.Sprintf("https://pkg.go.dev/%s#%s", pkg, frag)
+		}
+
+		if fi.Func == "" {
+			return nil, fmt.Errorf("empty function name: %s", name)
+		}
+		if fi.File == "" {
+			return nil, fmt.Errorf("empty function file: %s", name)
+		}
+		if fi.Desc == "" {
+			obj.Logf("empty function desc: %s", name)
+		}
+		if fi.Signature == nil {
+			obj.Logf("empty function sig: %s", name)
+		}
+
+		functions[name] = fi
+	}
+
+	return functions, nil
+}
+
+// Output is the type of the final data that will be for the json output.
+type Output struct {
+	// Version is the sha1 or ref name of this specific version. This is
+	// used if we want to generate documentation with links matching the
+	// correct version. If unspecified then this assumes git master.
+	Version string `json:"version"`
+
+	// Resources contains the collection of every available resource!
+	// FIXME: should this be a list instead?
+	Resources map[string]*ResourceInfo `json:"resources"`
+
+	// Functions contains the collection of every available function!
+	// FIXME: should this be a list instead?
+	Functions map[string]*FunctionInfo `json:"functions"`
+}
+
+// ResourceInfo stores some information about each resource.
+type ResourceInfo struct {
+	// Name is the golang name of this resource.
+	Name string `json:"name"`
+
+	// Kind is the kind of this resource.
+	Kind string `json:"kind"`
+
+	// File is the file name where this resource exists.
+	File string `json:"file"`
+
+	// Desc explains what this resource does.
+	Desc string `json:"description"`
+
+	// Fields is a collection of each resource field and corresponding info.
+	Fields map[string]*ResourceFieldInfo `json:"fields"`
+}
+
+// ResourceFieldInfo stores some information about each field in each resource.
+type ResourceFieldInfo struct {
+	// Name is what this field is called in golang format.
+	Name string `json:"name"`
+
+	// Type is the mcl type for this field.
+	Type string `json:"type"`
+
+	// Desc explains what this field does.
+	Desc string `json:"description"`
+}
+
+// FunctionInfo stores some information about each function.
+type FunctionInfo struct {
+	// Name is the golang name of this function. This may be an actual
+	// function if used by the simple API, or the name of a struct.
+	Name string `json:"name"`
+
+	// Package is the import name to use to get to this function.
+	Package string `json:"package"`
+
+	// Func is the name of the function in that package.
+	Func string `json:"func"`
+
+	// File is the file name where this function exists.
+	File string `json:"file"`
+
+	// Desc explains what this function does.
+	Desc string `json:"description"`
+
+	// Signature is the type signature of this function. If empty then the
+	// signature is not known statically and it may be polymorphic.
+	Signature *string `json:"signature,omitempty"`
+}
+
+// commentCleaner takes a comment group and returns it as a clean string. It
+// removes the spurious newlines and programmer-focused comments. If there are
+// blank lines, it replaces them with a single newline. The idea is that the
+// webpage formatter would replace the newline with a <br /> or similar. This
+// code is a modified alternative of the ast.CommentGroup.Text() function.
+func commentCleaner(g *ast.CommentGroup) string {
+	if g == nil {
+		return ""
+	}
+	comments := make([]string, len(g.List))
+	for i, c := range g.List {
+		comments[i] = c.Text
+	}
+
+	lines := make([]string, 0, 10) // most comments are less than 10 lines
+	for _, c := range comments {
+		// Remove comment markers.
+		// The parser has given us exactly the comment text.
+		switch c[1] {
+		case '/':
+			//-style comment (no newline at the end)
+			c = c[2:]
+			if len(c) == 0 {
+				// empty line
+				break
+			}
+			if isDevComment(c[1:]) { // get rid of one space
+				continue
+			}
+			if c[0] == ' ' {
+				// strip first space - required for Example tests
+				c = c[1:]
+				break
+			}
+			//if isDirective(c) {
+			//	// Ignore //go:noinline, //line, and so on.
+			//	continue
+			//}
+		case '*':
+			/*-style comment */
+			c = c[2 : len(c)-2]
+		}
+
+		// Split on newlines.
+		cl := strings.Split(c, "\n")
+
+		// Walk lines, stripping trailing white space and adding to list.
+		for _, l := range cl {
+			lines = append(lines, stripTrailingWhitespace(l))
+		}
+	}
+
+	// Remove leading blank lines; convert runs of interior blank lines to a
+	// single blank line.
+	n := 0
+	for _, line := range lines {
+		if line != "" || n > 0 && lines[n-1] != "" {
+			lines[n] = line
+			n++
+		}
+	}
+	lines = lines[0:n]
+
+	// Concatenate all of these together. Blank lines should be a newline.
+	s := ""
+	for i, line := range lines {
+		if line == "" {
+			continue
+		}
+		s += line
+		if i < len(lines)-1 { // Is there another line?
+			if lines[i+1] == "" {
+				s += "\n" // Will eventually be a line break.
+			} else {
+				s += " "
+			}
+		}
+	}
+
+	return s
+}
+
+// TODO: should we use unicode.IsSpace instead?
+func isWhitespace(ch byte) bool { return ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r' }
+
+// TODO: should we replace with a strings package stdlib function?
+func stripTrailingWhitespace(s string) string {
+	i := len(s)
+	for i > 0 && isWhitespace(s[i-1]) {
+		i--
+	}
+	return s[0:i]
+}
+
+// isPrivate specifies if a field name is "private" or not.
+func isPrivate(fieldName string) bool {
+	if fieldName == "" {
+		panic("invalid field name")
+	}
+	x := fieldName[0:1]
+
+	if strings.ToLower(x) == x {
+		return true // it was already private
+	}
+
+	return false
+}
+
+// isDevComment tells us that the comment is for developers only!
+func isDevComment(comment string) bool {
+	if strings.HasPrefix(comment, "TODO:") {
+		return true
+	}
+	if strings.HasPrefix(comment, "FIXME:") {
+		return true
+	}
+	if strings.HasPrefix(comment, "XXX:") {
+		return true
+	}
+	return false
+}
+
+// safeVersion parses the main version string and returns a short hash for us.
+// For example, we might get a string of 0.0.26-176-gabcdef012-dirty as input,
+// and we'd want to return abcdef012.
+func safeVersion(version string) string {
+	const dirty = "-dirty"
+
+	s := version
+	if strings.HasSuffix(s, dirty) { // helpful dirty remover
+		s = s[0 : len(s)-len(dirty)]
+	}
+
+	ix := strings.LastIndex(s, "-")
+	if ix == -1 { // assume we have a standalone version (future proofing?)
+		return s
+	}
+	s = s[ix+1:]
+
+	// From the `git describe` man page: The "g" prefix stands for "git" and
+	// is used to allow describing the version of a software depending on
+	// the SCM the software is managed with. This is useful in an
+	// environment where people may use different SCMs.
+	const g = "g"
+	if strings.HasPrefix(s, g) {
+		s = s[len(g):]
+	}
+
+	return s
+}

docs/index.rst

@@ -0,0 +1,17 @@
+.. mgmt documentation master file, created by
+   sphinx-quickstart on Wed Feb 15 21:34:09 2017.
+   You can adapt this file completely to your liking, but it should at least
+   contain the root `toctree` directive.
+
+Welcome to mgmt's documentation!
+================================
+
+.. toctree::
+   :maxdepth: 2
+   :caption: Contents:
+
+   documentation
+   quick-start-guide
+   resource-guide
+   prometheus
+   puppet-guide

docs/on-the-web.md

@@ -0,0 +1,65 @@
+# On the web
+
+Here is a list of places mgmt has appeared on the web. Feel free to send a patch
+if we missed something that you think is relevant!
+
+## Links
+
+| Author | Format | Subject |
+|---|---|---|
+| James Shubin | blog | [Next generation configuration mgmt](https://purpleidea.com/blog/2016/01/18/next-generation-configuration-mgmt/) |
+| James Shubin | video | [Introductory recording from DevConf.cz 2016](https://www.youtube.com/watch?v=GVhpPF0j-iE&html5=1) |
+| James Shubin | video | [Introductory recording from CfgMgmtCamp.eu 2016](https://www.youtube.com/watch?v=fNeooSiIRnA&html5=1) |
+| Julian Dunn | video | [On mgmt at CfgMgmtCamp.eu 2016](https://www.youtube.com/watch?v=kfF9IATUask&t=1949&html5=1) |
+| Walter Heck | slides | [On mgmt at CfgMgmtCamp.eu 2016](http://www.slideshare.net/olindata/configuration-management-time-for-a-4th-generation/3) |
+| Marco Marongiu | blog | [On mgmt](http://syslog.me/2016/02/15/leap-or-die/) |
+| Felix Frank | blog | [From Catalog To Mgmt (on puppet to mgmt "transpiling")](https://ffrank.github.io/features/2016/02/18/from-catalog-to-mgmt/) |
+| James Shubin | blog | [Automatic edges in mgmt (...and the pkg resource)](https://purpleidea.com/blog/2016/03/14/automatic-edges-in-mgmt/) |
+| James Shubin | blog | [Automatic grouping in mgmt](https://purpleidea.com/blog/2016/03/30/automatic-grouping-in-mgmt/) |
+| John Arundel | tweet | [“Puppet’s days are numbered.”](https://twitter.com/bitfield/status/732157519142002688) |
+| Felix Frank | blog | [Puppet, Meet Mgmt (on puppet to mgmt internals)](https://ffrank.github.io/features/2016/06/12/puppet,-meet-mgmt/) |
+| Felix Frank | blog | [Puppet Powered Mgmt (puppet to mgmt tl;dr)](https://ffrank.github.io/features/2016/06/19/puppet-powered-mgmt/) |
+| James Shubin | blog | [Automatic clustering in mgmt](https://purpleidea.com/blog/2016/06/20/automatic-clustering-in-mgmt/) |
+| James Shubin | video | [Recording from CoreOSFest 2016](https://www.youtube.com/watch?v=KVmDCUA42wc&html5=1) |
+| James Shubin | video | [Recording from DebConf16](http://meetings-archive.debian.net/pub/debian-meetings/2016/debconf16/Next_Generation_Config_Mgmt.webm) |
+| Felix Frank | blog | [Edging It All In (puppet and mgmt edges)](https://ffrank.github.io/features/2016/07/12/edging-it-all-in/) |
+| Felix Frank | blog | [Translating All The Things (puppet to mgmt translation warnings)](https://ffrank.github.io/features/2016/08/19/translating-all-the-things/) |
+| James Shubin | video | [Recording from systemd.conf 2016](https://www.youtube.com/watch?v=_TowsFAWWRA) |
+| James Shubin | blog | [Remote execution in mgmt](https://purpleidea.com/blog/2016/10/07/remote-execution-in-mgmt/) |
+| James Shubin | video | [Recording from High Load Strategy 2016](https://www.youtube.com/watch?v=-4g14KUVPVk) |
+| James Shubin | video | [Recording from NLUUG 2016](https://www.youtube.com/watch?v=0vO93ni1zos) |
+| James Shubin | blog | [Send/Recv in mgmt](https://purpleidea.com/blog/2016/12/07/sendrecv-in-mgmt/) |
+| Julien Pivotto | blog | [Augeas resource for mgmt](https://purpleidea.com/cached/mgmt-augeas.html) (Cached from: https://roidelapluie.be/blog/2017/02/14/mgmt-augeas/) |
+| James Shubin | blog | [Metaparameters in mgmt](https://purpleidea.com/blog/2017/03/01/metaparameters-in-mgmt/) |
+| James Shubin | video | [Recording from Incontro DevOps 2017](https://vimeo.com/212241877) |
+| Yves Brissaud | blog | [mgmt aux HumanTalks Grenoble (french)](http://log.winsos.net/2017/04/12/mgmt-aux-human-talks-grenoble.html) |
+| James Shubin | video | [Recording from OSDC Berlin 2017](https://www.youtube.com/watch?v=LkEtBVLfygE&html5=1) |
+| Jonathan Gold | blog | [AWS:EC2 in mgmt](https://jonathangold.ca/blog/aws-ec2-in-mgmt/) |
+| James Shubin | video | [Recording from OSMC Nuremberg 2017](https://www.youtube.com/watch?v=hSVadQLeplU&html5=1) |
+| James Shubin | video | [Recording from LCA 2018, Developers Miniconf](https://www.youtube.com/watch?v=OvgGfW0ilbE) |
+| James Shubin | video | [Recording from LCA 2018, Sysadmin Miniconf](https://www.youtube.com/watch?v=ELq1XOJMIPY) |
+| James Shubin | video | [Recording from LCA 2018, Main Conference](https://www.youtube.com/watch?v=_9PG64AOQ3w) |
+| James Shubin | video | [Recording from DevConf.cz 2017](https://www.youtube.com/watch?v=-FPEK08l1Zk) |
+| James Shubin | video | [Recording from FOSDEM 2018, Config Management Devroom](https://video.fosdem.org/2018/UA2.114/mgmt.webm) |
+| James Shubin | blog | [Mgmt Configuration Language](https://purpleidea.com/blog/2018/02/05/mgmt-configuration-language/) |
+| James Shubin | video | [Recording from CfgMgmtCamp.eu 2018](https://www.youtube.com/watch?v=NxObmwZDyrI) |
+| Jonathan Gold | blog | [Go Netlink and Select](https://jonathangold.ca/blog/go-netlink-and-select/) |
+| James Shubin | video | [Recording from DevOpsDays Montreal 2018](https://www.youtube.com/watch?v=1i38c5cooHo) |
+| James Shubin | video | [Recording from FOSDEM Minimalistic Languages Devroom 2019](https://video.fosdem.org/2019/K.4.201/mgmtconfig.webm) |
+| James Shubin | video | [Recording from FOSDEM Infra Management Devroom 2019](https://video.fosdem.org/2019/UB2.252A/mgmt.webm) |
+| James Shubin | video | [Recording from FOSDEM Graph Processing Devroom 2019](https://video.fosdem.org/2019/H.1308/graph_mgmt_config.webm) |
+| James Shubin | video | [Recording from FOSDEM Virtualization Devroom 2019](https://video.fosdem.org/2019/H.2213/vai_real_time_virtualization_automation.webm) |
+| James Shubin | video | [Recording from FOSDEM Containers Devroom 2019](https://video.fosdem.org/2019/UA2.114/containers_mgmt.webm) |
+| James Shubin | video | [Recording from FOSDEM Monitoring Devroom 2019](https://video.fosdem.org/2019/UB2.252A/real_time_merging_of_config_management_and_monitoring.webm) |
+| James Shubin | blog | [Mgmt Configuration Language: Class and Include](https://purpleidea.com/blog/2019/07/26/class-and-include-in-mgmt/) |
+| James Shubin | video | [Recording from FOSDEM 2020, Main Track (History)](https://video.fosdem.org/2020/Janson/automation.webm) |
+| James Shubin | video | [Recording from FOSDEM 2020, Infra Management Devroom](https://video.fosdem.org/2020/UA2.120/mgmt.webm) |
+| James Shubin | video | [Recording from FOSDEM 2020, Minimalistic Languages Devroom](https://video.fosdem.org/2020/AW1.125/mgmtconfigmore.webm) |
+| James Shubin | video | [Recording from CfgMgmtCamp.eu 2020](https://www.youtube.com/watch?v=Kd7FAORFtsc) |
+| James Shubin | video | [Recording from CfgMgmtCamp.eu 2023](https://www.youtube.com/watch?v=FeRGRj8w0BU) |
+| James Shubin | video | [Recording from FOSDEM 2024, Golang Devroom](https://video.fosdem.org/2024/ud2218a/fosdem-2024-2575-single-binary-full-stack-provisioning.mp4) |
+| James Shubin | video | [Recording from CfgMgmtCamp.eu 2024](https://www.youtube.com/watch?v=vBt9lpGD4bc) |
+| James Shubin | blog | [Mgmt Configuration Language: Functions](https://purpleidea.com/blog/2024/11/22/functions-in-mgmt/) |
+| James Shubin | blog | [Modules and imports in mgmt](https://purpleidea.com/blog/2024/12/03/modules-and-imports-in-mgmt/) |
+| James Shubin | video | [Recording from FOSDEM 2025, Docs Devroom](https://video.fosdem.org/2025/k4201/fosdem-2025-6143-docs-straight-from-the-code-ast-powered-automation.mp4) |
+| James Shubin | video | [Recording from CfgMgmtCamp.eu 2025](https://www.youtube.com/watch?v=0Oa7CWx4TEA) |

docs/prometheus.md

@@ -0,0 +1,66 @@
+# Prometheus support
+
+Mgmt comes with a built-in prometheus support. It is disabled by default, and
+can be enabled with the `--prometheus` command line switch.
+
+By default, the prometheus instance will listen on [`127.0.0.1:9233`][pd]. You
+can change this setting by using the `--prometheus-listen` cli option:
+
+To have mgmt prometheus bind interface on 0.0.0.0:45001, use:
+`./mgmt r --prometheus --prometheus-listen :45001`
+
+## Metrics
+
+Mgmt exposes three kinds of resources: _go_ metrics, _etcd_ metrics and _mgmt_
+metrics.
+
+### go metrics
+
+We use the [prometheus go_collector][pgc] to expose go metrics. Those metrics
+are mainly useful for debugging and perf testing.
+
+### etcd metrics
+
+mgmt exposes etcd metrics. Read more in the [upstream documentation][etcdm]
+
+### mgmt metrics
+
+Here is a list of the metrics we provide:
+
+- `mgmt_resources_total`: The number of resources that mgmt is managing
+- `mgmt_checkapply_total`: The number of CheckApply's that mgmt has run
+- `mgmt_failures_total`: The number of resources that have failed
+- `mgmt_failures`: The number of resources that have failed
+- `mgmt_graph_start_time_seconds`: Start time of the current graph since unix
+epoch in seconds
+
+For each metric, you will get some extra labels:
+
+- `kind`: The kind of mgmt resource
+
+For `mgmt_checkapply_total`, those extra labels are set:
+
+- `eventful`: "true" or "false", if the CheckApply triggered some changes
+- `errorful`: "true" or "false", if the CheckApply reported an error
+- `apply`: "true" or "false", if the CheckApply ran in apply or noop mode
+
+## Alerting
+
+You can use prometheus to alert you upon changes or failures. We do not provide
+such templates yet, but we plan to provide some examples in this repository.
+Patches welcome!
+
+## Grafana
+
+We do not have grafana dashboards yet. Patches welcome!
+
+## External resources
+
+- [prometheus website](https://prometheus.io/)
+- [prometheus documentation](https://prometheus.io/docs/introduction/overview/)
+- [prometheus best practices regarding metrics naming](https://prometheus.io/docs/practices/naming/)
+- [grafana website](http://grafana.org/)
+
+[pgc]: https://github.com/prometheus/client_golang/blob/master/prometheus/go_collector.go
+[etcdm]: https://coreos.com/etcd/docs/latest/metrics.html
+[pd]: https://github.com/prometheus/prometheus/wiki/Default-port-allocations

docs/puppet-guide.md

@@ -0,0 +1,316 @@
+# Puppet guide
+
+`mgmt` can use Puppet as its source for the configuration graph.
+This document goes into detail on how this works, and lists
+some pitfalls and limitations.
+
+For basic instructions on how to use the Puppet support, see
+the [main documentation](documentation.md#puppet-support).
+
+## Prerequisites
+
+You need Puppet installed in your system. It is not important how you
+get it. On the most common Linux distributions, you can use packages
+from the OS maintainer, or upstream Puppet repositories. An alternative
+that will also work on OSX is the `puppet` Ruby gem. It also has the
+advantage that you can install any desired version in your home directory
+or any other location.
+
+Any release of Puppet's 3.x and 4.x series should be suitable for use with
+`mgmt`. Most importantly, make sure to install the `ffrank-mgmtgraph` Puppet
+module (referred to below as "the translator module").
+
+```
+puppet module install ffrank-mgmtgraph
+```
+
+Please note that the module is not required on your Puppet master (if you
+use a master/agent setup). It's needed on the machine that runs `mgmt`.
+You can install the module on the master anyway, so that it gets distributed
+to your agents through Puppet's `pluginsync` mechanism.
+
+### Testing the Puppet side
+
+The following command should run successfully and print a YAML hash on your
+terminal:
+
+```puppet
+puppet mgmtgraph print --code 'file { "/tmp/mgmt-test": ensure => present }'
+```
+
+You can use this CLI to test any manifests before handing them straight
+to `mgmt`.
+
+## Writing a suitable manifest
+
+### Unsupported attributes
+
+`mgmt` inherited its resource module from Puppet, so by and large, it's quite
+possible to express `mgmt` graphs in terms of Puppet manifests. However,
+there isn't (and likely never will be) full feature parity between the
+respective resource types. In consequence, a manifest can have semantics that
+cannot be transferred to `mgmt`.
+
+For example, at the time of writing this, the `file` type in `mgmt` had no
+notion of permissions (the file `mode`) yet. This lead to the following
+warning (among others that will be discussed below):
+
+```
+$ puppet mgmtgraph print --code 'file { "/tmp/foo": mode => "0600" }'
+Warning: cannot translate: File[/tmp/foo] { mode => "600" } (attribute is ignored)
+```
+
+This is a heads-up for the user, because the resulting `mgmt` graph will
+in fact not pass this information to the `/tmp/foo` file resource, and
+`mgmt` will ignore this file's permissions. Including such attributes in
+manifests that are written expressly for `mgmt` is not sensible and should
+be avoided.
+
+### Unsupported resources
+
+Puppet has a fairly large number of
+[built-in types](https://www.puppet.com/docs/puppet/8/cheatsheet_core_types.html),
+and countless more are available through
+[modules](https://forge.puppet.com/). It's unlikely that all of them will
+eventually receive native counterparts in `mgmt`.
+
+When encountering an unknown resource, the translator module will replace
+it with an `exec` resource in its output. This resource will run the equivalent
+of a `puppet resource` command to make Puppet apply the original resource
+itself. This has quite abysmal performance, because processing such a
+resource requires the forking of at least one Puppet process (two if it
+is found to be out of sync). This comes with considerable overhead.
+On most systems, starting up any Puppet command takes several seconds.
+Compared to the split second that the actual work usually takes,
+this overhead can amount to several orders of magnitude.
+
+Avoid Puppet types that `mgmt` does not implement (yet).
+
+### Avoiding common warnings
+
+Many resource parameters in Puppet take default values. For the most part,
+the translator module just ignores them. However, there are cases in which
+Puppet will default to convenient behavior that `mgmt` cannot quite replicate.
+For example, translating a plain `file` resource will lead to a warning message:
+
+```
+$ puppet mgmtgraph print --code 'file { "/tmp/mgmt-test": }'
+Warning: File[/tmp/mgmt-test] uses the 'puppet' file bucket, which mgmt cannot
+do. There will be no backup copies!
+```
+
+The reason is that per default, Puppet assumes the following parameter value
+(among others)
+
+```puppet
+file { "/tmp/mgmt-test":
+	backup => 'puppet',
+}
+```
+
+To avoid this, specify the parameter explicitly:
+
+```bash
+puppet mgmtgraph print --code 'file { "/tmp/mgmt-test": backup => false }'
+```
+
+This is tedious in a more complex manifest. A good simplification is the
+following [resource default](https://www.puppet.com/docs/puppet/8/lang_defaults)
+anywhere on the top scope of your manifest:
+
+```puppet
+File { backup => false }
+```
+
+If you encounter similar warnings from other types and/or parameters,
+use the same approach to silence them if possible.
+
+## Configuring Puppet
+
+Since `mgmt` uses an actual Puppet CLI behind the scenes, you might
+need to tweak some of Puppet's runtime options in order to make it
+do what you want. Reasons for this could be among the following:
+
+* You use the `--puppet agent` variant and need to configure
+`servername`, `certname` and other master/agent-related options.
+* You don't want runtime information to end up in the `vardir`
+that is used by your regular `puppet agent`.
+* You install specific Puppet modules for `mgmt` in a non-standard
+location.
+
+`mgmt` exposes only one Puppet option in order to allow you to
+control all of them, through its `--puppet-conf` option. It allows
+you to specify which `puppet.conf` file should be used during
+translation.
+
+```
+mgmt run puppet --puppet /opt/my-manifest.pp --puppet-conf /etc/mgmt/puppet.conf
+```
+
+Within this file, you can just specify any needed options in the
+`[main]` section:
+
+```
+[main]
+server=mgmt-master.example.net
+vardir=/var/lib/mgmt/puppet
+```
+
+## Caveats
+
+Please see the [README](https://github.com/ffrank/puppet-mgmtgraph/blob/master/README.md)
+of the translator module for the current state of supported and unsupported
+language features.
+
+You should probably make sure to always use the latest release of
+both `ffrank-mgmtgraph` and `ffrank-yamlresource` (the latter is
+getting pulled in as a dependency of the former).
+
+## Using Puppet in conjunction with the mcl lang
+
+The graph that Puppet generates for `mgmt` can be united with a graph
+that is created from native `mgmt` code in its mcl language. This is
+useful when you are in the process of replacing Puppet with mgmt. You
+can translate your custom modules into mgmt's language one by one,
+and let mgmt run the current mix.
+
+Instead of the usual `--puppet-conf` flag and argv for `puppet` and `mcl` input,
+you need to use alternative flags to make this work:
+
+* `--lp-lang` to specify the mcl input
+* `--lp-puppet` to specify the puppet input
+* `--lp-puppet-conf` to point to the optional puppet.conf file
+
+`mgmt` will derive a graph that contains all edges and vertices from
+both inputs. You essentially get two unrelated subgraphs that run in
+parallel. To form edges between these subgraphs, you have to define
+special vertices that will be merged. This works through a hard-coded
+naming scheme.
+
+### Mixed graph example 1 - No merges
+
+```mcl
+# lang
+file "/tmp/mgmt_dir/" { state => "present" }
+file "/tmp/mgmt_dir/a" { state => "present" }
+```
+
+```puppet
+# puppet
+file { "/tmp/puppet_dir": ensure => "directory" }
+file { "/tmp/puppet_dir/a": ensure => "file" }
+```
+
+These very simple inputs (including implicit edges from directory to
+respective file) result in two subgraphs that do not relate.
+
+```
+File[/tmp/mgmt_dir/] -> File[/tmp/mgmt_dir/a]
+
+File[/tmp/puppet_dir] -> File[/tmp/puppet_dir/a]
+```
+
+### Mixed graph example 2 - Merged vertex
+
+In order to have merged vertices in the resulting graph, you will
+need to include special resources and classes in the respective
+input code.
+
+* On the lang side, add `noop` resources with names starting in `puppet_`.
+* On the Puppet side, add **empty** classes with names starting in `mgmt_`.
+
+```mcl
+# lang
+noop "puppet_handover_to_mgmt" {}
+file "/tmp/mgmt_dir/" { state => "present" }
+file "/tmp/mgmt_dir/a" { state => "present" }
+
+Noop["puppet_handover_to_mgmt"] -> File["/tmp/mgmt_dir/"]
+```
+
+```puppet
+# puppet
+class mgmt_handover_to_mgmt {}
+include mgmt_handover_to_mgmt
+
+file { "/tmp/puppet_dir": ensure => "directory" }
+file { "/tmp/puppet_dir/a": ensure => "file" }
+
+File["/tmp/puppet_dir/a"] -> Class["mgmt_handover_to_mgmt"]
+```
+
+The new `noop` resource is merged with the new class, resulting in
+the following graph:
+
+```
+File[/tmp/puppet_dir] -> File[/tmp/puppet_dir/a]
+				|
+				V
+		Noop[handover_to_mgmt]
+			|
+			V
+	File[/tmp/mgmt_dir/] -> File[/tmp/mgmt_dir/a]
+```
+
+You put all your ducks in a row, and the resources from the Puppet input
+run before those from the mcl input.
+
+**Note:** The names of the `noop` and the class must be identical after the
+respective prefix. The common part (here, `handover_to_mgmt`) becomes the name
+of the merged resource.
+
+## Mixed graph example 3 - Multiple merges
+
+In most scenarios, it will not be possible to define a single handover
+point like in the previous example. For example, if some Puppet resources
+need to run in between two stages of native resources, you need at least
+two merged vertices:
+
+```mcl
+# lang
+noop "puppet_handover" {}
+noop "puppet_handback" {}
+file "/tmp/mgmt_dir/" { state => "present" }
+file "/tmp/mgmt_dir/a" { state => "present" }
+file "/tmp/mgmt_dir/puppet_subtree/state-file" { state => "present" }
+
+File["/tmp/mgmt_dir/"] -> Noop["puppet_handover"]
+Noop["puppet_handback"] -> File["/tmp/mgmt_dir/puppet_subtree/state-file"]
+```
+
+```puppet
+# puppet
+class mgmt_handover {}
+class mgmt_handback {}
+
+include mgmt_handover, mgmt_handback
+
+class important_stuff {
+	file { "/tmp/mgmt_dir/puppet_subtree":
+		ensure => "directory"
+	}
+	# ...
+}
+
+Class["mgmt_handover"] -> Class["important_stuff"] -> Class["mgmt_handback"]
+```
+
+The resulting graph looks roughly like this:
+
+```
+File[/tmp/mgmt_dir/] -> File[/tmp/mgmt_dir/a]
+	|
+	V
+Noop[handover] -> ( class important_stuff resources )
+			|
+			V
+		Noop[handback]
+			|
+			V
+File[/tmp/mgmt_dir/puppet_subtree/state-file]
+```
+
+You can add arbitrary numbers of merge pairs to your code bases,
+with relationships as needed. From our limited experience, code
+readability suffers quite a lot from these, however. We advise
+to keep these structures simple.

docs/quick-start-guide.md

@@ -0,0 +1,127 @@
+# Quick start guide
+
+## Introduction
+
+This guide is intended for users and developers. If you're brand new to `mgmt`,
+it's probably a good idea to start by reading an
+[introductory article about the engine](https://purpleidea.com/blog/2016/01/18/next-generation-configuration-mgmt/)
+and an [introductory article about the language](https://purpleidea.com/blog/2018/02/05/mgmt-configuration-language/).
+[There are other articles and videos available](on-the-web.md) if you'd like to
+learn more or prefer different formats. Once you're familiar with the general
+idea, or if you prefer a hands-on approach, please start hacking...
+
+## Getting mgmt
+
+You can either build `mgmt` from source, or you can download a pre-built
+release. There are also some distro repositories available, but they may not be
+up to date. A pre-built release is the fastest option if there's one that's
+available for your platform. If you are developing or testing a new patch to
+`mgmt`, or there is not a release available for your platform, then you'll have
+to build your own.
+
+### Downloading a pre-built release:
+
+The latest releases can be found [here](https://github.com/purpleidea/mgmt/releases/).
+An alternate mirror is available [here](https://dl.fedoraproject.org/pub/alt/purpleidea/mgmt/releases/).
+
+Make sure to verify the signatures of all packages before you use them. The
+signing key can be downloaded from [https://purpleidea.com/contact/#pgp-key](https://purpleidea.com/contact/#pgp-key)
+to verify the release.
+
+If you've decided to install a pre-build release, you can skip to the
+[Running mgmt](#running-mgmt) section below!
+
+### Building a release:
+
+You'll need some dependencies, including `golang`, and some associated tools.
+
+#### Installing golang
+
+* You need a modern golang version installed.
+	* To install on rpm style systems: `sudo dnf install golang`
+	* To install on apt style systems: `sudo apt install golang`
+	* To install on macOS systems install [Homebrew](https://brew.sh)
+	and run: `brew install go`
+* You can run `go version` to check the golang version.
+* If your distro is too old, you may need to [download](https://golang.org/dl/)
+a newer golang version.
+
+#### Setting up golang
+
+* You can skip this step, as your installation will default to using `~/go/`,
+but if you do not have a `GOPATH` yet and want one in a custom location, create
+one and export it:
+
+```shell
+mkdir $HOME/gopath
+export GOPATH=$HOME/gopath
+```
+
+* You might also want to add the GOPATH to your `~/.bashrc` or `~/.profile`.
+* For more information you can read the
+[GOPATH documentation](https://golang.org/cmd/go/#hdr-GOPATH_environment_variable).
+
+#### Getting the mgmt code and associated dependencies
+
+* Download the `mgmt` code and switch to that directory:
+
+```shell
+git clone --recursive https://github.com/purpleidea/mgmt/ ~/mgmt/
+cd ~/mgmt/
+```
+
+* Add `$GOPATH/bin` to `$PATH`
+
+```shell
+export PATH=$PATH:$GOPATH/bin
+```
+
+* Run `make deps` to install system and golang dependencies. Take a look at
+`misc/make-deps.sh` if you want to see the details of what it does.
+
+#### Building mgmt
+
+* Now run `make` to get a freshly built `mgmt` binary. If this succeeds, you can
+proceed to the [Running mgmt](#running-mgmt) section below!
+
+### Installing a distro release
+
+Installation of `mgmt` from distribution packages currently needs improvement.
+They are not always up-to-date with git master and as such are not recommended.
+At the moment we have:
+* [COPR](https://copr.fedoraproject.org/coprs/purpleidea/mgmt/) (currently dead)
+* [Arch](https://aur.archlinux.org/packages/mgmt/) (currently stale)
+
+Please contribute more and help improve these! We'd especially like to see a
+Debian package!
+
+### Building from a container:
+
+This method avoids polluting your workstation with the dependencies for the
+build. Here is an example using Fedora, Podman and Buildah:
+
+```shell
+git clone --recursive https://github.com/purpleidea/mgmt/
+cd mgmt
+docker build -t mgmt -f docker/Dockerfile .
+docker run --rm --entrypoint cat mgmt mgmt > mgmt
+chmod +x mgmt
+./mgmt --version
+# you could now copy the mgmt binary somewhere into your $PATH
+# e.g., /usr/local/bin/ to make it accessible from anywhere
+```
+
+## Running mgmt
+
+* Run `mgmt run --tmp-prefix lang examples/lang/hello0.mcl` to try out a very
+simple example! If you built it from source, you'll need to use `./mgmt` from
+the project directory.
+* Look in that example file that you ran to see if you can figure out what it
+did! You can press `^C` to exit `mgmt`.
+* Have fun hacking on our future technology and get involved to shape the
+project!
+
+## Examples
+
+Please look in the [examples/lang/](../examples/lang/) folder for some more
+examples!

docs/release-notes/0.0.10

@@ -0,0 +1,51 @@
+I've just released version 0.0.10 of mgmt!
+
+NEWS
+
+57 files changed, 1991 insertions(+), 752 deletions(-)
+
+* There's a new resource called `KV`. Short examples exist, but I
+haven't yet published a whole integration showing the usefulness.
+
+* A major race was fixed. The issue of what to do with BackPokes during
+start/pause was never previously solved. I had this as an open issue on
+my whiteboard for a while, and I finally got some time to work through
+it. The answer wasn't that difficult, but I think it was shrouded in
+some tunnel vision. See the commit messages and source comments for the
+details.
+
+* The GAPI grew four new associated World API methods: StrWatch,
+StrGet, StrSet, StrDel, and the associated etcd backed implementations.
+These are quite useful when combined with the KV resource.
+
+* There are now P/V style counting semaphores available as metaparams.
+This is particularly cool because the implementation is (AFAIK,
+assuming no bugs) dead-lock free! This is mentioned in my recent blog
+post.
+
+* See the git log for more NEWS, and sorry for anything notable I left
+out!
+
+BUGS
+
+* There's a `concurrent map write` bug in the semaphore implementation
+which is fixed in git master. Since it was a race, it was only caught
+after this release was made. I should also figure out if the sema check
+should go after the BackPoke or not.
+
+MISC
+
+We're still looking for new contributors, and there are easy, medium
+and hard issues available! You're also welcome to suggest your own!
+Please join us in #mgmtconfig on Freenode IRC, or ping this list if
+you'd like help getting started!
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest
+release:
+James Shubin, Julien Pivotto, Michael Borden.
+We had 3 unique committers since 0.0.9, and have had 30 overall.
+
+Happy hacking,
+James

docs/release-notes/0.0.11

@@ -0,0 +1,59 @@
+I've just released version 0.0.11 of mgmt!
+
+NEWS
+
+ 20 files changed, 579 insertions(+), 126 deletions(-)
+
+* Added a missing mutex around the semaphore map which prevents
+occasional panics
+
+* Removed exec pollint param which is not needed because of the poll
+metaparam
+
+* Fixed a state rechecking bug in exec resource (things are faster now)
+
+* Fixed the major annoyance of exec resources receiving main's signals.
+If we would ^C the main mgmt, the child processes would receive this
+too which was incorrect.
+
+* Fixed the deadlock on resource errors. This meant that previously if
+a resource failed, we would deadlock the graph from shutting down. This
+was bad and I'm glad it's now fixed. Sorry about that!
+
+* Improved the backpoke logic to not require semaphores since we used
+to take the lock even when we were going to backpoke which was
+unnecessary.
+
+* Added fast pausing to the graph. This means that a ^C or a pause
+transition used to wait for the whole graph to roll through, but it now
+finishes after the currently running resources finish executing. Read
+the commit messages for more background here including the discussion
+about a possible Interrupt() addition to the resource API.
+
+* Prometheus support has been updated!
+
+* See the git log for more NEWS, and sorry for anything notable I left
+out!
+
+BUGS
+
+* We're in pretty good shape now. There are some small issues, but
+nothing major that I don't know about.
+
+MISC
+
+We're still looking for new contributors, and there are easy, medium
+and hard issues available! You're also welcome to suggest your own!
+Please join us in #mgmtconfig on Freenode IRC, or ping this list if
+you'd like help getting started!
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest
+release:
+James Shubin, Julien Pivotto
+We had 2 unique committers since 0.0.10, and have had 30 overall.
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/0.0.12

@@ -0,0 +1,87 @@
+I've just released version 0.0.12 of mgmt!
+
+Sorry if I've been more quiet than usual, I've had to focus a lot of my
+time on GlusterFS related features ($dayjob official directives) and
+work there.
+
+One goal is to try and use libmgmt to either wholly or partially re-
+implement glusterd. As a result, a lot of my upstream focus has been
+re-prioritized to features needed for that effort.
+
+I wrote a PoC called gd3: https://github.com/purpleidea/gd3
+(It has now bit-rotted compared to upstream mgmt, but is easy to fix.)
+The initial scope looks like it will be much smaller, but hopefully
+this is interesting to you too. Ping me if you'd like to help.
+
+We desperately need your contributions if we're going to get mgmt
+standalone into a MVP. To motivate you, there's some great new stuff
+that landed since 0.0.11, including:
+
+* a great new YAML parser from contributor Mildred
+
+* a huge pgraph refactor (to remove internal deps and cycles)
+
+* a great amount of new tests and testing
+
+and so much more...
+
+NEWS
+
+ 76 files changed, 7549 insertions(+), 4269 deletions(-)
+
+* The svc resource now also supports user services
+
+* There's a fabulous new yaml parser that fixes a longstanding issue in
+my original code. Try it with --yaml2. I'll remove the old one
+eventually. Thanks to contributor Mildred for this great work!
+
+* Refactored the lib/ etcd usage into the GAPI's for a cleaner main
+
+* World API grew some new methods for libmgmt users
+
+* pgraph refactor and cleanup, now it's a fairly clean standalone pkg
+
+* pgraph functions to flatten/merge in subgraphs along with examples
+
+* Giant resource refactor to hopefully make things more logical, and to
+simplify the resource API. This also introduces the mgraph struct to
+add the higher level graph knowledge outside of pgraph.
+
+* A partial implementation of a "Graph" (recursive subgraph?) resource!
+See the code for details, as help is wanted to finish this. This should
+help elucidate what the most elegant design for the mgmt core should
+be.
+
+* Send/Recv support for the exec resource as output, stdout, and stderr
+
+* GAPI improvements to support exit requests and fast pausing
+
+* AutoEdge API improvements including a fix+test for a regression
+
+* A possible fix for the possible etcd server startup race
+
+* A fun amount of new tests all over including for gometalinter
+
+* See the git log for more NEWS, and for anything notable I left out!
+
+BUGS
+
+* We fixed a bunch of stuff, and added more tests!
+
+MISC
+
+We're still looking for new contributors, and there are easy, medium
+and hard issues available! You're also welcome to suggest your own!
+Please join us in #mgmtconfig on Freenode IRC, or ping this list if
+you'd like help getting started!
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest
+release:
+James Shubin, Julien Pivotto, Mildred Ki'Lya
+We had 3 unique committers since 0.0.11, and have had 30 overall.
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/0.0.13

@@ -0,0 +1,89 @@
+I've just released version 0.0.13 of mgmt!
+
+I guess this is an appropriate number for a scary October release.
+
+We recently re-licensed to the more permissive GPL. I put a lot of
+thought into it, and also wrote up a short blog post about some of the
+reasoning. It's here:
+
+https://ttboj.wordpress.com/2017/10/17/copyleft-is-dead-long-live-copyl
+eft/
+
+If you read to the end you'll also see that Red Hat is not funding my
+mgmt work anymore. This is too bad, and means I'll only have small
+amounts of personal time available to work on this. If you'd like to
+help fund my work, or know someone who'd like to, please let me know!
+
+Having said that, there's some great new stuff that landed since
+0.0.12, including:
+
+* new resources from new contributor Jonathan Gold (aws, group, user)
+
+* an HCL frontend from new contributor Chris McKenzie
+
+* polish in a number of places including in the nspawn resource
+
+and so much more... If you'd prefer to have releases more often, then
+please let me know! Lastly, the language and a number of associated
+parts are on its way. I hope to push this monster patch to git master
+before February.
+
+It's also worth mentioning that we have 17 resources now! wow.
+
+NEWS
+
+ 140 files changed, 3921 insertions(+), 848 deletions(-)
+
+* Many improvements to tests, testing and small fixes to avoid false-
+failures on travis.
+
+* golint now reports 0 issues.
+
+* An HCL frontend if you'd prefer that to the YAML. Also a great
+example of how to plug in a new frontend.
+
+* An update to golang 1.8 as the minimum version required.
+
+* Bump the etcd version to 3.2.6+ -- Looking forward to a 3.3 release
+which should probably include some patches we upstreamed.
+
+* Addition of new user and group resources. These also include a bunch
+of automatic edges.
+
+* Addition of an AWS resource! I've wanted this for a while, as it
+demonstrates nicely how event based cloud resources can fit nicely into
+our design. There's still a lot to do, and we have some suggestions for
+Amazon too. If you have a contact there, please put me in touch!
+
+* Our nspawn resource is more polished now.
+
+* See the git log for more NEWS, and for anything notable I left out!
+
+MISC
+
+We're still looking for new contributors, and there are easy, medium
+and hard issues available! You're also welcome to suggest your own!
+Please join us in #mgmtconfig on Freenode IRC, or ping this list if
+you'd like help getting started!
+
+MENTORING
+
+We offer mentoring for new golang/mgmt hackers who want to get
+involved. This is free and friendly. You get to improve your skills,
+and we get some patches in return. Ping me off-list for details.
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest
+release:
+AdnanLFC, Arthur Mello, ChrisMcKenzie, Dennis Kliban, Ismael Puerto,
+James Shubin, Jonathan Gold, Juan Luis de Sousa-Valadas Castaño, Juan-
+Luis de Sousa-Valadas Castaño (although I suspect the last two are the
+same ;))
+
+We had 9 unique committers since 0.0.12, and have had 38 overall.
+Run 'git log 0.0.12..0.0.13' to see what has changed since 0.0.12
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/0.0.14

@@ -0,0 +1,81 @@
+I've just released version 0.0.14 of mgmt!
+
+> 118 files changed, 2688 insertions(+), 974 deletions(-)
+
+There's some great new stuff that landed since
+0.0.13, including:
+
+* amazon AWS EC2 resource is now in git master.
+
+* more automatic edges from new contributor Guillaume Herail (xiu)
+
+* a move to golang 1.8 or higher
+
+and so much more... This will probably be the last release before the
+language lands in git master. It's a pretty giant patch coming :/
+
+NEWS
+
+* We're > 1k stars on GitHub now. It's a silly metric, but ¯\_(ツ)_/¯
+
+* Jonathan Gold has done a lot of hard work on the AWS EC2 resource,
+and it's now in git master. There are still many things we'd like to
+do, but it's a great start on what is a *monster* resource, and
+hopefully it will inspire others to get involved.
+
+In particular, it was a great learning experience (for me in
+particular!) about how bad the EC2 golang API is. There are some
+notable design bugs we found, and if anyone from Amazon engineering
+would like to reach out to us, we'd love to provide some constructive
+ideas.
+
+* Guillaume Herail (xiu) wrote some really nice patches, and picked up
+on the autoedges API very quickly. Hopefully he'll have time to work on
+even more!
+
+* Paul Morgan sent us some nice shell fixups-- many more exist in an
+open PR that didn't make it into this release. Hopefully we'll get
+those merged by 0.0.15
+
+* Felix Frank did a few Puppet compiler fix ups. I think he's been
+refreshing his work with new resources recently...
+
+* We're looking for help writing Google, DigitalOcean, Rackspace, etc
+resources if anyone is interested, reach out to us. Particularly if
+there is support from those organizations as well.
+
+* See the git log for more NEWS, and for anything notable I left out!
+
+EVENTS
+
+There are a bunch of upcoming mgmt talks and events! Stay tuned for
+details in the coming email, but TL;DR: Linux Conf Australia, FOSDEM, &
+CfgMgmtCamp.eu -- from three different speakers, and including a
+hackathon too!
+
+MISC
+
+We're still looking for new contributors, and there are easy, medium
+and hard issues available! You're also welcome to suggest your own!
+Please join us in #mgmtconfig on Freenode IRC, or ping this list if
+you'd like help getting started! Expect many new tagged #mgmtlove
+issues within the month.
+
+MENTORING
+
+We offer mentoring for new golang/mgmt hackers who want to get
+involved. This is free and friendly. You get to improve your skills,
+and we get some patches in return. Ping me off-list for details.
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest
+release:
+Felix Frank, Guillaume Herail, James Shubin, Jonathan Gold,
+jonathangold, Julien Pivotto, Paul Morgan, Toshaan Bharvani
+We had 8 unique committers since 0.0.13, and have had 41 overall.
+run 'git log 0.0.13..0.0.14' to see what has changed since 0.0.13
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/0.0.15

@@ -0,0 +1,116 @@
+I've just released version 0.0.15 of mgmt!
+
+> 328 files changed, 29869 insertions(+), 943 deletions(-)
+
+(Yeah, that's almost 30k+ LOC)
+
+There's some great new stuff that landed since 0.0.14, including:
+
+* THE LANGUAGE (mcl)
+
+* "Deploys": a distributed way to push code into your cluster
+
+* Scheduling (as a reactive function)
+
+* Better testing
+
+* a move to etcd 3.3+ and golang 1.9+
+
+and so much more... This is a monster release. Please try out the
+language and all the other new features today :)
+
+NEWS
+
+* We released the language. Please play around with it :) It's time to
+get used to this cool new paradigm. Learn more from the...
+
+Blog post:
+https://purpleidea.com/blog/2018/02/05/mgmt-configuration-language/
+
+Video:
+https://www.youtube.com/watch?v=NxObmwZDyrI
+
+Docs:
+https://github.com/purpleidea/mgmt/blob/master/docs/language-guide.md
+
+Function guide:
+https://github.com/purpleidea/mgmt/blob/master/docs/function-guide.md
+
+And tons of code all over git master. Check the lang/ folder.
+
+* There is a reactive scheduler in the language. Use your imagination,
+or play around with:
+https://github.com/purpleidea/mgmt/blob/3ad7097c8aa7eab7f895aab9af22338
+c0cf82986/lang/funcs/core/schedule_polyfunc.go#L18
+
+* There is a "deploys" feature. It's not documented yet. You should
+poke around if you're curious. Consider this an early soft release.
+
+* There is a FS implementation to store files in a POSIX-like layer on
+top of etcd. It's used by deploys. It needs more tests though :)
+
+* The language grew two "simple" API's for implementing functions, so
+that new functionality can be exposed in the mgmt language.
+
+* The language grew two ways to specify edges between resources: either
+internal to the resource, or externally as standalone edges.
+
+* The language now supports optional resource parameters via the
+"elvis" operator. This keeps things type safe and avoids needing an
+"undef" or "nil" in the language. This operator also works for edge
+declarations.
+
+* New contributor Johan Bloemberg has been on fire sending patches!
+He has already made some great improvements to our Makefile for
+testing, and the addition of the env* functions in the language, with
+much more code pending in open PR's.
+
+* Initial debian packaging has been added. It now needs a maintainer to
+build, upload, and love it :)
+
+* We have an early emacs major mode for "mcl", our language.
+
+* Lots of new documentation has been added. Particularly for developers
+wanting to contribute to the project.
+
+* We're looking for help writing Google, DigitalOcean, Rackspace, etc
+resources if anyone is interested, reach out to us. Particularly if
+there is support from those organizations as well.
+
+* See the git log for more NEWS, and for anything notable I left out!
+
+MISC
+
+We're still looking for new contributors, and there are easy, medium
+and hard issues available! You're also welcome to suggest your own!
+Please join us in #mgmtconfig on Freenode IRC, or ping this list if
+you'd like help getting started! For details please see:
+
+https://github.com/purpleidea/mgmt/blob/master/docs/faq.md#how-do-i-con
+tribute-to-the-project-if-i-dont-know-golang
+
+Many new tagged #mgmtlove issues were tagged:
+https://github.com/purpleidea/mgmt/issues?q=is%3Aissue+is%3Aopen+label%
+3Amgmtlove
+
+MENTORING
+
+We offer mentoring for new golang/mgmt hackers who want to get
+involved.
+This is free and friendly. You get to improve your skills,
+and we get
+some patches in return. Ping me off-list for details.
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest
+release:
+Carsten Thiel, dsx, James Shubin, Joe Julian, Johan Bloemberg, Jonathan
+Gold, jonathangold, karimb, Oliver Frommel, Peter Oliver, Toshaan
+Bharvani, Wim
+We had 12 unique committers since 0.0.14, and have had 48 overall.
+run 'git log 0.0.14..0.0.15' to see what has changed since 0.0.14
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/0.0.16

@@ -0,0 +1,104 @@
+I've just released version 0.0.16 of mgmt!
+
+> 220 files changed, 14243 insertions(+), 9491 deletions(-)
+
+Woo...
+
+There's some great new stuff that landed since 0.0.15, including:
+
+* A giant engine re-write! (Makes resource writing more elegant too.)
+
+* New resources!!
+
+* New language features!!!
+
+and so much more... This is a monster release. Please try out the new
+features today :)
+
+NEWS
+
+* New resources include: net, mount and docker:container. Jonathan was
+responsible for all of these. Please take them for a spin! He's looking
+for a job too, and would probably be happy to get paid to work on mgmt.
+
+* We're > 1.5k stars on GitHub now. It's a silly metric, but ¯\_(ツ)_/¯
+
+* A giant engine refactoring/re-write was done. This cleaned up the
+code significantly, and made it more elegant to write resources.
+Unfortunately there is one small bug that I missed and that I haven't
+fixed yet. It rarely happens except during some of our tests during
+shutdown, which causes intermittent failures. It shouldn't block you
+playing with mgmt.
+
+* The language "class" and "include" statements have been added. These
+are important pieces for writing reusable modules which are coming
+soon. Try them out! (This comes with a bunch of tests too.)
+
+* We have an integration testing framework. It's pretty cool, it spins
+up a full mgmt cluster and runs stuff. Try it out or add some tests.
+
+* I had fun fixing a big bug: 06ee05026b0c743d19c7d62675f8ddeabdc8dd4f
+
+* I removed the remote execution functionality from core. I realized it
+could be re-written as a resource, and it was also in the way from some
+other cleanups that were more important. Half the new code is done,
+ping me if this is a priority for you or you want to help.
+
+* I also removed the HCL front-end, because mcl is usable enough to be
+more fun to play with, and I wanted to refactor some code. If someone
+really wants it back, let me know.
+
+* We have some release building scripts in git master, so you can now
+download pre-built (with fpm) RPM, DEB, or PACMAN packages! They're
+signed too. https://github.com/purpleidea/mgmt/releases/tag/0.0.16
+
+* We're looking for help writing Google, DigitalOcean, Rackspace, etc
+resources if anyone is interested, reach out to us. Particularly if
+there is support from those organizations as well.
+
+* Many other bug fixes, changes, etc...
+
+* See the git log for more NEWS, and for anything notable I left out!
+
+MISC
+
+I took a bit of a break recently to catch up on some life stuff, but I
+think I'm back on track. While git master hasn't been especially busy,
+there's an active feature branch at feat/import which contains some fun
+stuff, with a very WIP giant patch still sitting on my machine. I hope
+to finish it up soon and then do another release. That branch contains
+one of the last big features before I'll really be ready to run mgmt on
+my personal servers!
+
+We're still looking for new contributors, and there are easy, medium
+and hard issues available! You're also welcome to suggest your own!
+Please join us in #mgmtconfig on Freenode IRC, or ping this list if
+you'd like help getting started! For details please see:
+
+https://github.com/purpleidea/mgmt/blob/master/docs/faq.md#how-do-i-con
+tribute-to-the-project-if-i-dont-know-golang
+
+Many new tagged #mgmtlove issues were tagged:
+https://github.com/purpleidea/mgmt/issues?q=is%3Aissue+is%3Aopen+label%
+3Amgmtlove
+
+MENTORING
+
+We offer mentoring for new golang/mgmt hackers who want to get
+involved.
+This is free and friendly. You get to improve your skills,
+and we get
+some patches in return. Ping me off-list for details.
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest
+release:
+Alan Jenkins, James Shubin, jesus m. rodriguez, Jonathan Gold,
+jonathangold, Lauri Ojansivu, phaer
+We had 7 unique committers since 0.0.15, and have had 52 overall.
+run 'git log 0.0.15..0.0.16' to see what has changed since 0.0.15
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/0.0.17

@@ -0,0 +1,111 @@
+I've just released version 0.0.17 of mgmt!
+
+> 269 files changed, 13281 insertions(+), 1633 deletions(-)
+
+There's some very useful stuff that landed since 0.0.16, including:
+
+* Modules and import system now exists!
+* A lot of tests, fixes and a huge new test infra was added
+* Merging puppet with mcl code is now possible (madness!)
+* We made a small change to the cli UI
+* Bump to golang 1.10 (please update your environments)
+
+And much more...
+
+DOWNLOAD
+
+Prebuilt binaries are available here:
+https://github.com/purpleidea/mgmt/releases/tag/0.0.17
+
+NEWS
+
+* One of the biggest missing features was the lack of a module/import
+system. After some initial exploration on what turned out to be a dead-
+end, I found what I think is a very elegant approach, which is now in
+this release. Please try it out, there are docs available. I hope to
+write a blog post about it soon.
+
+(There's one additional "kind" of import that I'm considering, similar
+to a macro "#include", that I might add. To be determined. Let me know
+if you find anything missing as of today.)
+
+* Felix added the first version of his mcl+puppet frontend. This should
+allow you to more cleverly merge legacy puppet environments with mcl
+code. It's fantastic, take a look.
+
+* Jonathan added a systemd-timer resource. This is a great replacement
+for cron.
+
+* We changed the CLI ui to improve the determinism of the frontend
+selection. Basically we changed from: `mgmt run --lang code.mcl` to:
+`mgmt run lang --lang code.mcl`. Remember to put --tmp-prefix after
+`run` directly where it is used.
+
+* We made a whole bunch of cleanups to the test infra, added new test
+infra for testing complex mcl modules and the import/module system, and
+of course added new tests.
+
+* You can pass a list of strings as the resource name to build that
+many resources. (Looping/iteration!)
+
+* You can specify all the metaparams and auto-* properties in mcl now.
+
+* Native mcl code can be used to write imported core code.
+
+* There was a bug that snuck into the pkg res. This has now been fixed.
+
+* A small, long-time copy+pasta error bug was fixed in Exec.
+
+* Virtually all the imports of the "log" package are at the top-level
+now. This will make moving to a new logger easier in the future. I have
+an innovative logger idea that I have a design for that I'll eventually
+get to.
+
+* A few workarounds for occasional test failures were added. Some
+legacy code needs a cleanup, and it's not done yet. Fortunately, none
+of these issues seem to occur in real-life as far as I can tell, and
+are caused by closing down mgmt at weird times.
+
+* Found a bug (now fixed) in the upstream lexer Yikes! See:
+57ce3fa587897d74634c1216af67dd42252c64e5
+
+* We're looking for help writing Amazon, Google, DigitalOcean, etc
+resources if anyone is interested, reach out to us. Particularly if
+there is support from those organizations as well.
+
+* Many other bug fixes, changes, etc...
+
+* See the git log for more NEWS, and for anything notable I left out!
+
+MISC
+
+We're still looking for new contributors, and there are easy, medium
+and hard issues available! You're also welcome to suggest your own!
+Please join us in #mgmtconfig on Freenode IRC, or ping this list if
+you'd like help getting started! For details please see:
+
+https://github.com/purpleidea/mgmt/blob/master/docs/faq.md#how-do-i-con
+tribute-to-the-project-if-i-dont-know-golang
+
+Many new tagged #mgmtlove issues were tagged:
+https://github.com/purpleidea/mgmt/issues?q=is%3Aissue+is%3Aopen+label%
+3Amgmtlove
+
+MENTORING
+
+We offer mentoring for new golang/mgmt hackers who want to get
+involved. This is fun and friendly! You get to improve your skills,
+and we get some patches in return. Ping me off-list for details.
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest
+release:
+Felix Frank, James Shubin, Jonathan Gold, Kevin Kuehler, Michael Lesko-
+Krleza, Tom Payne, Vincent Membré
+We had 7 unique committers since 0.0.16, and have had 56 overall.
+run 'git log 0.0.16..0.0.17' to see what has changed since 0.0.16
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/0.0.18

@@ -0,0 +1,106 @@
+I've just released version 0.0.18 of mgmt!
+
+> 202 files changed, 5606 insertions(+), 1880 deletions(-)
+
+There's some great stuff that landed since 0.0.17, including:
+
+* A re-write of the core engine algorithm
+* Tests are very stable
+* At least three old bugs were killed
+* An infra to write tests for individual resources was added
+
+And much more...
+
+This adds a significant amount of polish and bug fixes to mgmt. We're
+on the home stretch to MVP!
+
+DOWNLOAD
+
+Prebuilt binaries are available here:
+https://github.com/purpleidea/mgmt/releases/tag/0.0.18
+
+NEWS
+
+* There was a rare race that would panic the engine on shutdown. This
+only seemed to happen in CPU/system call starved environments like
+travis-ci. This was due to some ignorance when writing this early part
+of the code base. The algorithm has been re-written, and this also
+removed the use of at least one mutex. Things should be stable now, and
+also much faster. (Although perf was never an issue.)
+
+* A hidden race/deadlock in the exec resource was found and killed.
+Woo! Some new tools to help find these and other problems are in misc/
+
+* The early converger code was re-written. I was not as knowledgeable
+about golang in the very beginning, and this code needed refreshing. It
+contained a rare deadlock which needed to be killed.
+
+* Toshaan added an uptime() function.
+
+* Julien added a method for generating some simple functions for the
+language.
+
+* Lander added two new functions.
+
+* James added a new readfile() function, and other examples.
+
+* The template function now allows you to use imported functions. They
+use underscores instead of periods for namespace separation due to a
+limitation in the template library.
+
+* Kevin and I killed a tricky race in the SocketSet code! Woo :) Kevin
+also added a great cpucount() fact!
+
+* James gave a number of presentations at FOSDEM. Some recordings are
+available: https://purpleidea.com/talks/
+
+* We're looking for help writing Amazon, Google, DigitalOcean, etc
+resources if anyone is interested, reach out to us. Particularly if
+there is support from those organizations as well.
+
+* Many other bug fixes, changes, etc...
+
+* See the git log for more NEWS, and for anything notable I left out!
+
+BUGS
+
+* An unfortunate bug in the type unification code was found. This can
+cause small code bases to take a lot of ram/cpu to run. This will be
+prioritized in an upcoming release. Until then you'll have to avoid
+fancy type unification. (Specify types you know when it has to guess.)
+
+If efficient type unification algorithms are your specialty, please let
+us know, we'd like your help!
+
+MISC
+
+We're still looking for new contributors, and there are easy, medium
+and hard issues available! You're also welcome to suggest your own!
+Please join us in #mgmtconfig on Freenode IRC, or ping this list if
+you'd like help getting started! For details please see:
+
+https://github.com/purpleidea/mgmt/blob/master/docs/faq.md#how-do-i-con
+tribute-to-the-project-if-i-dont-know-golang
+
+Many tagged #mgmtlove issues exist:
+https://github.com/purpleidea/mgmt/issues?q=is%3Aissue+is%3Aopen+label%
+3Amgmtlove
+
+MENTORING
+
+We offer mentoring for new golang/mgmt hackers who want to get
+involved. This is fun and friendly! You get to improve your skills,
+and we get some patches in return. Ping me off-list for details.
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest
+release:
+Felix Frank, James Shubin, Jeff Waugh, Johan Bloemberg, Julien Pivotto,
+Kevin Kuehler, Lander Van den Bulcke, Toshaan Bharvani
+We had 8 unique committers since 0.0.17, and have had 58 overall.
+run 'git log 0.0.17..0.0.18' to see what has changed since 0.0.17
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/0.0.19

@@ -0,0 +1,131 @@
+I've just released version 0.0.19 of mgmt!
+
+> 361 files changed, 10451 insertions(+), 3919 deletions(-)
+
+This is a very important (and huge) release and has some important
+fixes that landed since 0.0.18, including:
+
+* A huge re-write of the elastic etcd clustering code base
+* A significant improvement in the type unification algorithm
+* An important import/class scoping bug was discovered and fixed
+* New mcl functions and resource improvements
+
+And much more...
+
+What comes next is just polish, new features and small bug fixes!
+
+DOWNLOAD
+
+Prebuilt binaries are available here:
+https://github.com/purpleidea/mgmt/releases/tag/0.0.19
+
+NEWS
+
+* A giant etcd re-write was completed and merged. The elastic
+clustering algorithm is not perfect, however it should suffice for most
+use cases, and it's always possible to point mgmt at an external etcd
+cluster if you don't understand the limitations of the automatic
+clustering algorithm. The important part is that the core code is much
+cleaner now, so hopefully races and bugs of ignorance are gone now. :)
+
+* I found an unfortunate bug in the type unification algorithm that
+severely impacted performance for some types of code bases. This is now
+fixed, and I hope we should not experience problems again! Special
+thanks to Sam for talking me through the problem and understanding the
+space better! Woo \o/
+
+* An important import/class scoping bug was fixed. Thanks to Nicolas
+for the bug report. We also added tests for this too!
+
+* Nicolas also added our first os detection function. os.is_debian and
+os.is_redhat are now in core. Get your favourite os added today!
+
+* The polymorphic len function can also check str length.
+
+* The exec resource got a big cleanup. It also learned the interrupt
+trait so that long running commands can be forcefully killed if need
+be.
+
+* A fancy new test infra for testing functions over time was added.
+Anytime we want to check our individual FRP functions are working as
+expected, this is an easy way to add a test. This way, if we ever find
+a bug, we can drop in a test with the fix. This actually helped find a
+very subtle bug in readfile that nobody had experienced yet!
+
+* File res with state => exists but no content now performs as
+expected.
+
+* Improved send/recv, since it was neglected a bit. Hopefully it ends
+up being a useful primitive.
+
+* Added a new synchronization primitive that I'm called
+SubscribedSignal. I found it very useful for building some of my code,
+and I hope you'll find it useful too. I'd offer it upstream to the sync
+package if Google didn't force their crappy CLA nonsense on everyone
+who wanted to send a patch. :/ Death by 1000 paper cuts, I guess.
+
+* Added a match function in the new regexp core package. Try it out and
+add some more functions!
+
+* Wouter has been testing mgmt and filling all sorts of useful bug
+reports. We fixed at least one related to a report, and more are
+planned for the next release. Wouter also sent in one cleanup patch to
+remove some dead code. Welcome to the project!
+
+* We're looking for help writing Amazon, Google, DigitalOcean, etc
+resources if anyone is interested, reach out to us. Particularly if
+there is support from those organizations as well.
+
+* Many other bug fixes, changes, etc...
+
+* See the git log for more NEWS, and for anything notable I left out!
+
+BUGS
+
+* There are a few known issues, in particular with some over eager
+checking done in the Validate portion of two resources, that should
+actually be runtime checks in CheckApply. As a result, if you intend to
+change some state during the graph execution, the resource won't see
+it. These should be very easy to fix if someone is interested in
+writing the patch!
+
+TALKS
+
+* James will be presenting at this year's OSDC in Berlin. There will be
+a workshop: https://osdc.de/events/mgmt-config-workshop/
+and a talk:
+https://osdc.de/events/mgmt-config-the-future-of-your-autonomous-datacentre/
+Sign up soon if you want to guarantee a spot, as they're limited!
+
+MISC
+
+We're still looking for new contributors, and there are easy, medium
+and hard issues available! You're also welcome to suggest your own!
+Please join us in #mgmtconfig on Freenode IRC, or ping this list if
+you'd like help getting started! For details please see:
+
+https://github.com/purpleidea/mgmt/blob/master/docs/faq.md#how-do-i-con
+tribute-to-the-project-if-i-dont-know-golang
+
+Many tagged #mgmtlove issues exist:
+https://github.com/purpleidea/mgmt/issues?q=is%3Aissue+is%3Aopen+label%
+3Amgmtlove
+
+MENTORING
+
+We offer mentoring for new golang/mgmt hackers who want to get
+involved. This is fun and friendly! You get to improve your skills,
+and we get some patches in return. Ping me off-list for details.
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest
+release:
+Adam Sigal, Felix Frank, James Shubin, Jonathan Gold, Michael Schubert,
+Mitch Fossen, Nicolas Charles, Wouter Dullaert
+We had 8 unique committers since 0.0.18, and have had 63 overall.
+run 'git log 0.0.18..0.0.19' to see what has changed since 0.0.18
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/0.0.20

@@ -0,0 +1,145 @@
+I've just released version 0.0.20 of mgmt!
+
+> 295 files changed, 8585 insertions(+), 1413 deletions(-)
+
+This was a very challenging release but it includes many useful changes
+since 0.0.19, including:
+
+* Function values / lambdas exist and are first-class
+* Over 70 new tests have been added!
+* Core functions, classes, and globals can now be written in mcl code
+* A new compiler "Ordering" step was added
+
+And much more...
+
+DOWNLOAD
+
+Prebuilt binaries are available here:
+https://github.com/purpleidea/mgmt/releases/tag/0.0.20
+
+NEWS
+
+* After a long and challenging road, I finally got function values and
+lambdas merged. If you find any bugs, please let me know! You can now
+treat functions as first-class values, and even use them as closures by
+capturing variable state.
+
+* Over 70 new tests were added, most of which test the behaviour of the
+new functions.
+
+* Core packages always allowed you to write new functions in pure
+golang, but now you can implement new functions, classes, and even
+variables in native mcl code! It's still desirable and perhaps
+efficient in some cases to want native golang implementations, but all
+good programs self-host some of their stdlib in their own language
+eventually.
+
+* A new compiler step called "Ordering" was added. It's hidden inside
+the SetScope step, but now lets us generate code ordering graphs and
+determine exactly what to run first.
+
+* Light copying of Node's allows more correct and efficient function
+graphs that can share common vertices and edges. For example, if two
+different closures capture a variable $x, they'll both use the same
+copy when running the function, since the compiler can prove if they're
+identical.
+
+* Improved the type system slightly to allow advanced type comparisons.
+
+* The type unification algorithm was improved. Hopefully it should
+solve all scenarios without needing the recursive solver which was very
+slow. If you find a case that isn't speedy, please let us know!
+
+* Added subtest listing by using -short and -v in a test. This lets you
+know what's available and how to run individual sub tests easily.
+
+* Support for the systemd STATE_DIRECTORY and xdg cache dir was added
+by new contributor John! Thanks!
+
+* New contributor Adam added a pgraph test.
+
+* A bug in the systemd mount resource was fixed. Hopefully it should
+work correctly now.
+
+* A bug that prevented us from allowing nested system imports was
+fixed. Nest away! This will pave the way for us to automatically import
+most of the golang standard library by doing: import "golang/regexp" or
+golang/whatever".
+
+* Added an example showing that unicode is allowed in strings.
+
+* Fixed a rare race in the engine.
+
+* Added some new core functions including math.mod and datetime
+improvements.
+
+* Changed the API to remove the use of --lang. This avoids the
+stuttering.
+
+* Moved to golang 1.11 and etcd 3.3.13. The later includes a fix for an
+un-catchable error scenario which we fixed in etcd.
+
+* Improved the pgraph library significantly so that we can generate
+better graphs with accurate vertices based on the vertex pointers.
+
+* Added ArchLinux OS family detection.
+
+* We're looking for help writing Amazon, Google, DigitalOcean, etc
+resources if anyone is interested, reach out to us. Particularly if
+there is support from those organizations as well.
+
+* Many other bug fixes, changes, etc...
+
+* See the git log for more NEWS, and for anything notable I left out!
+
+BUGS
+
+* There are a few known issues with some disabled code paths in the new
+function value code. These issues don't *need* to be fixed, but if they
+are, then we should see a slight performance increase. Happy to have
+someone dig into these, and they shouldn't bother anyone.
+
+* Some of the pre-built binaries might not work on your system. We need
+to start building them with the right dependencies so that `ldd`
+related things are happy. For now, please try building yourself if the
+build doesn't work for you, or help improve our build system.
+
+TALKS
+
+I'll be giving a talk at an upcoming mini-conference in Montreal. If
+you're interested in attending, please let me know.
+If you'd like to give an mgmt talk somewhere, please let me know!
+
+MISC
+
+We're still looking for new contributors, and there are easy, medium
+and hard issues available! You're also welcome to suggest your own!
+Please join us in #mgmtconfig on Freenode IRC, or ping this list if
+you'd like help getting started! For details please see:
+
+https://github.com/purpleidea/mgmt/blob/master/docs/faq.md#how-do-i-con
+tribute-to-the-project-if-i-dont-know-golang
+
+Many tagged #mgmtlove issues exist:
+https://github.com/purpleidea/mgmt/issues?q=is%3Aissue+is%3Aopen+label%
+3Amgmtlove
+
+MENTORING
+
+We offer mentoring for new golang/mgmt hackers who want to get
+involved. This is fun and friendly! You get to improve your skills,
+and we get some patches in return. Ping me off-list for details.
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest
+release:
+Adam Sigal, Christian Rebischke, Felix Frank, James Shubin, Jan
+Martens, Johan Bloemberg, John Hooks, Ward Vandewege
+We had 8 unique committers since 0.0.19, and have had 67 overall.
+run 'git log 0.0.19..0.0.20' to see what has changed since 0.0.19
+
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/0.0.21

@@ -0,0 +1,133 @@
+I've just released version 0.0.21 of mgmt!
+
+> 178 files changed, 4351 insertions(+), 829 deletions(-)
+
+This was a very lonely release but it includes some very useful
+additions since 0.0.20, including:
+
+* The first mgmt meme!
+* Working distro packages for Fedora, Debian, Ubuntu and Arch!
+* Reversible resources!
+* A deploy package to let you read files from the active deploy
+* Improved file resource behaviours
+
+And much more...
+
+DOWNLOAD
+
+Prebuilt binaries are available here:
+https://github.com/purpleidea/mgmt/releases/tag/0.0.21
+
+NEWS
+
+* Someone made a cool mgmt meme. Look in art/mgmt_*_meme.jpg
+
+* Distro packages are now built properly, so they should all work now.
+We have builds for Fedora-30, Fedora-29, Debian-10, Ubuntu-Bionic, and
+Archlinux. If you'd like a build for a different distro/version please
+let me know.
+
+* We finally got rid of the old `Compare(...) bool` API, and moved to
+`Cmp(...) error`. We'll now get more useful information from Res
+compares when they differ. Thanks to new contributor Donald Bakong for
+working on this. He's ramping up his golang contributions, so we expect
+to see more from him in the future!
+
+* We now have reversible resources. Basically if you create a resource
+and specify the reverse metaparam, eg: `Meta:reverse => true`, then if
+a resource is removed (either because a new version of code doesn't
+have it anymore OR more importantly if it was inside an `if` block that
+became false) then the engine will perform some "reverse" action for
+it. For a file, if it was added, we'll remove it. If it was edited,
+we'll undo the edit. If we added ugo+w, we'll remove that. And so on.
+The engine bits are done, and as well so have the file resource bits.
+It should be easy to add this for any other resource where it makes
+sense. This will likely be a very powerful feature that we use a lot.
+
+* The file resource was changed slightly so that by default the "state"
+is undefined. As a result, if you want a file to be created and none is
+present, you need to specify the state. Otherwise specifying "content"
+will only edit a file if it already exists, and otherwise be an error.
+It turns out this is actually a better behaviour, even if it's not
+necessarily intuitive for puppet users. It turns out it simplifies the
+code drastically and makes the reversible file resource much more
+logical. It seems that Puppet and Ansible got this wrong, but Cfengine
+got it right. IIRC. Do you agree? (Look at the code!)
+
+* We now catch CR \r characters in code so that you don't wonder why
+the compiler is telling you about unexpected whitespace. This should
+make your life easier.
+
+* You can now read files from within the deploy. This can be used for
+templates or anything else. This was one of the last missing things
+that was blocking me from writing useful mcl modules.
+
+* Fixed a copy-pasta bug where the != operator (for strings only) was
+actually doing an ==. Woops! The good news is that we've been shaking
+out silly bugs because I've been using mgmt more and more. Hopefully
+there aren't any woops ones like this left!
+
+* A bunch of function, class, and include tests were added. We're
+getting really well tested!
+
+* We're looking for help writing Amazon, Google, DigitalOcean, etc
+resources if anyone is interested, reach out to us. Particularly if
+there is support from those organizations as well.
+
+* Many other bug fixes, changes, etc...
+
+* See the git log for more NEWS, and for anything notable I left out!
+
+BUGS
+
+* Function values as args don't work yet. This is blocking us from
+implementing functions like map/reduce/filter, because they'd want to
+receive a function as input. TBH, I'm a bit tunnel-visioned on this,
+because I'm not the compilers genius that you are. If you can help,
+please let me know. I'll be posting a bunch of test cases that show
+what's needed shortly.
+
+* Three patches have been submitted to mkosi to support the image
+building I've been doing. They're not merged yet, so you'll have to
+apply them yourself if you want to make your own distro images. This
+isn't a major requirement anyone should have, but if they're not
+merged, we'll store them here and apply them as needed.
+
+TALKS
+
+I'll be in Belgium for FOSDEM and CfgMgmtCamp in 2020. If I'm lucky
+I'll have at least one mgmt presentation. I might also consider going
+to DevConf.cz if I get a talk accepted. Feel to ping me if you'd like
+to hack, get consulting, training, etc while I'm in Europe!
+
+MISC
+
+We're still looking for new contributors, and there are easy, medium
+and hard issues available! You're also welcome to suggest your own!
+Please join us in #mgmtconfig on Freenode IRC, or ping this list if
+you'd like help getting started! For details please see:
+
+https://github.com/purpleidea/mgmt/blob/master/docs/faq.md#how-do-i-con
+tribute-to-the-project-if-i-dont-know-golang
+
+Many tagged #mgmtlove issues exist:
+https://github.com/purpleidea/mgmt/issues?q=is%3Aissue+is%3Aopen+label%
+3Amgmtlove
+
+MENTORING
+
+We offer mentoring for new golang/mgmt hackers who want to get
+involved. This is fun and friendly! You get to improve your skills,
+and we get some patches in return. Ping me off-list for details.
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest
+release:
+bjanssens, Donald Bakong, James Shubin
+We had 3 unique committers since 0.0.20, and have had 69 overall.
+run 'git log 0.0.20..0.0.21' to see what has changed since 0.0.20
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/0.0.22

@@ -0,0 +1,160 @@
+I've just released version 0.0.22 of mgmt!
+
+> 579 files changed, 17984 insertions(+), 3136 deletions(-)
+
+Compared to the last release, this is a monster. Previously:
+
+> 178 files changed, 4351 insertions(+), 829 deletions(-)
+
+I apologize for not doing a release earlier, but to be quite honest,
+I've been busy, the people who are playing with mgmt are doing their
+own builds anyways, and there are still some unimplemented, pre-
+production features missing.
+
+Also, I started a new job. News on my blog and how (if at all) it
+affects mgmt is there.
+
+This is still an incredibly important release, so let's cover some of
+the points!
+
+* This is the last release before we switch to go.mod
+* IRC channel moved to #mgmtconfig on libera.chat after Freenode died
+* New resources including tftp, dhcp, and http (all as servers, wow!)
+* New string interpolation implementation with many tests
+* Resource fields can accept complex structs and other types now
+* Improved type unification solver and new invariants like generator
+* A new polymorphic function API interface
+
+And much more...
+
+DOWNLOAD
+
+Prebuilt binaries are NOT available here for this release:
+https://github.com/purpleidea/mgmt/releases/tag/0.0.22
+
+NEWS
+
+* The file resource supports building files from other "fragments".
+This is magic and automatic and real-time. Docs and examples are in the
+repo.
+
+* The file resource (and others) have a new trait and queryable API to
+make decisions based on what other resources are in the graph.
+
+* The file resource has a "purge" option to remove unmanaged files from
+a managed directory.
+
+* A lot of built-in functions are auto-generated from the stdlib. Most
+things you would want are now present, particularly if they're pure
+functions.
+
+* There's a new consul KV resource.
+
+* File resources support symbolic modes now!
+
+* New tftp related resources are now present. They're great and I use
+them to provision things!
+
+* A docker image resource was added.
+
+* First-class constants now exist. So you can do
+$const.res.file.state.exists instead of typing "exists" which is prone
+to typos. This is more verbose, but it's safer if that's your priority.
+
+* We found a bug with fuzzing! Cool, thanks Patrick!
+
+* We have dhcp server related resources. This is pretty cool when
+combined with the tftp resource and you can provision a lot of stuff
+from your laptop and one binary now.
+
+* We also have http server resources. Combined with the tftp and dhcp
+resources mgmt starts to look like a powerful tool to greenfield a new
+datacentre and then take over and manage it continuous. All from a
+single, type-safe, code base. Of course you can do other things with
+this, and I'm looking forward to seeing the ideas that I haven't
+thought of yet! PS: An http:ui has been partially implemented too. Ping
+if you want to know more.
+
+* Resource fields couldn't previously accept anonymous structs as types
+because of how golang built its reflect library. Joe found an elegant
+workaround, thanks!
+
+* The type unification solver was improved to support some new
+invariants. This makes a lot of new things possible, and was done to
+support new complex functions including the eventual addition of map,
+reduce, and filter. One of the new invariants is a "generator"
+invariant, so that unification can take into account the entire
+relevant parts of the AST. It's not a textbook CS implementation, but
+it's based on sound theory I think, and it seems to work great. If you
+find an edge case, please let us know.
+
+* The polymorphic function interface was changed to use the new
+unification logic. This makes a lot more sense. All the functions have
+been ported to the new interface.
+
+* 42
+
+* We're looking for help writing Amazon, Google, DigitalOcean, etc
+resources if anyone is interested, reach out to us. Particularly if
+there is support from those organizations as well.
+
+* Many other bug fixes, changes, etc...
+
+* See the git log for more NEWS, and for anything notable I left out!
+
+BUGS
+
+* Function values as args don't work yet. This is blocking us from
+implementing functions like map/reduce/filter, because they'd want to
+receive a function as input. TBH, I'm a bit tunnel-visioned on this,
+because I'm not the compilers genius that you are. If you can help,
+please let me know. I'll be posting a bunch of test cases that show
+what's needed shortly.
+
+(This is the exact message I wrote last time. I've made a lot of
+progress since then, but motivation here has been low. Reach out if you
+can help.)
+
+TALKS
+
+Hopefully CfgMgmtCamp in 2022 will be back on. If we're lucky and safe,
+maybe I can travel there. TBD... Feel to ping me if you'd like to hack,
+talk, whatever if I'm in Europe.
+
+MISC
+
+We're still looking for new contributors, and there are easy, medium
+and hard issues available! You're also welcome to suggest your own!
+Please join us in #mgmtconfig on Libera IRC, or ping this list if
+you'd like help getting started! For details please see:
+
+https://github.com/purpleidea/mgmt/blob/master/docs/faq.md#how-do-i-con
+tribute-to-the-project-if-i-dont-know-golang
+
+Many tagged #mgmtlove issues exist:
+https://github.com/purpleidea/mgmt/issues?q=is%3Aissue+is%3Aopen+label%
+3Amgmtlove
+
+Although asking in IRC is the best way to find something to work on.
+
+MENTORING
+
+We offer mentoring for new golang/mgmt hackers who want to get
+involved. This is fun and friendly! You get to improve your skills,
+and we get some patches in return. Ping me off-list for details.
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest
+release:
+Adam Sigal, Ahmed Al-Hulaibi, David Randall, Derek Buckley, Donald
+Bakong, Felix Frank, Francois Rompre-Lanctot, Ivan Pejić, James Shubin,
+Jean-Philippe Evrard, Jimmy Tang, Joe Groocock, Jonathan Gold, Julien
+Pivotto, Kenneth Hoste, Matthew Lesko-Krleza, Patrick Meyer, viq, Yohan
+Belval
+We had 19 unique committers since 0.0.21, and have had 82 overall.
+run 'git log 0.0.21..0.0.22' to see what has changed since 0.0.21
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/0.0.23

@@ -0,0 +1,102 @@
+I've just released version 0.0.23 of mgmt!
+
+>  424 files changed, 7051 insertions(+), 2256 deletions(-)
+
+This is a fairly quiet release, and I'm mostly doing this to have a
+permanent tag before I start really breaking git master.
+
+I'd like to apologize for things being kind of quiet. I've had to focus
+on life and making money to pay my bills, and I've been struggling a
+bit to complete some of the tougher algorithmic parts that I think are
+necessary for a solid MVP. Hopefully I will succeed, but to do so, it's
+going to be easier if I break git master and then sort things out
+later.
+
+I'm feeling optimistic about the future, although help with some
+complex concurrent programming would certainly be appreciated.
+
+With that, here are a few highlights from the release:
+
+* We're using go.mod, but I'm not keeping it up-to-date regularly yet.
+
+* We have an os.system(`cmd`) function!
+
+* We replaced go-bindata with the embed package.
+
+* We added a hetzner vm resource.
+
+* We did a giant lang/ package refactor.
+
+* Printf supports %v now (any type).
+
+And much more...
+
+DOWNLOAD
+
+Prebuilt binaries are NOT available here for this release:
+https://github.com/purpleidea/mgmt/releases/tag/0.0.23
+
+NEWS
+
+* We have our Libera IRC channel bridged to Matrix, so you can join
+that way too.
+
+* We're looking for help writing Amazon, Google, DigitalOcean, Hetzner,
+etc, resources if anyone is interested, reach out to us. Particularly
+if there is support from those organizations as well.
+
+* Many other bug fixes, changes, etc...
+
+* See the git log for more NEWS, and for anything notable I left out!
+
+BUGS
+
+* Function values as args don't work yet. This is blocking us from
+implementing functions like map/reduce/filter, because they'd want to
+receive a function as input.
+
+(This is the exact message I wrote last time. I've made a lot of
+progress since then, but motivation here has been low. Reach out if you
+can help.)
+
+TALKS
+
+I don't have anything planned until CfgMgmtCamp 2024. If you'd like to
+book me for a private event, or sponsor my travel for your conference,
+please let me know.
+
+MISC
+
+We're still looking for new contributors, and there are easy, medium
+and hard issues available! You're also welcome to suggest your own!
+Please join us in #mgmtconfig on Libera IRC or Matrix, or ping this
+list if you'd like help getting started! For details please see:
+
+https://github.com/purpleidea/mgmt/blob/master/docs/faq.md#how-do-i-con
+tribute-to-the-project-if-i-dont-know-golang
+
+Many tagged #mgmtlove issues exist:
+https://github.com/purpleidea/mgmt/issues?q=is%3Aissue+is%3Aopen+label%
+3Amgmtlove
+
+Although asking in IRC is the best way to find something to work on.
+
+MENTORING
+
+We offer mentoring for new golang/mgmt hackers who want to get
+involved. This is fun and friendly! You get to improve your skills,
+and we get some patches in return. Ping me off-list for details.
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest
+release:
+dantefromhell, James Shubin, Jef Masereel, Joe Groocock, Samuel
+Gélineau
+We had 5 unique committers since 0.0.22, and have had 85 overall.
+run 'git log 0.0.22..0.0.23' to see what has changed since 0.0.22
+
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/0.0.24

@@ -0,0 +1,161 @@
+I've just released version 0.0.24 of mgmt!
+
+
+> 600 files changed, 13622 insertions(+), 6907 deletions(-)
+
+This is a huge and hugely important release! It has been a long time
+coming. We have lambdas! I could not have done this without the
+unrelentingly supportive and brilliant Samuel Gélineau.
+
+Getting past the blockers and tricky code changes was all thanks to
+him. Cleanups, polish and making it more golang idiomatic was my doing.
+(The easy stuff.) If Sam wanted to be a golang expert, he could have
+done it all, but it was more sensible than I do all the mundane and
+filler stuff.
+
+With that, here are a few highlights from the release:
+
+* We have working lambdas, including iter.map =D
+
+* We have a new function engine!
+
+* We have improved type unification!
+
+* We have an improved resource engine!
+
+* We have improved many of the internal API's.
+
+* We have so many tests.
+
+And much more...
+
+DOWNLOAD
+
+Prebuilt binaries are NOT available here for this release:
+https://github.com/purpleidea/mgmt/releases/tag/0.0.24
+
+NEWS
+
+* Our main tests are now in the excellent .txtar format. This makes
+things much easier to manage.
+
+* The iter.map function can be named as such due to parser tricks! No
+need to name it xmap anymore!
+
+* The unification solver has been greatly improved. We can infer a lot
+more about function types.
+
+* The resources API uses the context package for closing Watch and
+returning early from CheckApply. The next step would be to remove all
+the resource-specific timeout code and make that a metaparam.
+
+* A new sync primitive has been added in case you'd like to use it
+somewhere. We'd love help adding an even more complex one. Look in
+util/sync.go for more information.
+
+* Sam added some beautiful type inference debugging that makes things
+easier for those familiar with the standard literature.
+
+* An important bug in standalone etcd has been fixed. While embedded
+etcd and automatic clustering isn't "supported" (it's buggy) the
+status-quo of using your own etcd cluster is stable, and you can even
+use the embedded etcd server in standalone mode...
+
+* This means you can run `mgmt etcd` and get the standard etcd binary
+behaviour that you'd get from running `etcd` normally. This makes it
+easy to use both together since you only need to transport one binary
+around. (And maybe mgmt will do that for you!)
+
+* I fixed and cleaned up some sketchy code in the resource engine. I
+had been unmotivated to fix this for a while because I really wanted
+lambdas first, but now that they are in, I took a good look at the
+code, made some fixes, and I'm really happy with it now.
+
+* Metaparams are appropriately stateful between graph switches now.
+Retry is the easy example. Limit/Burst need to be ported if you care
+about these fine details.
+
+* A RetryReset metaparam has been added. This is another good example
+of how powerful metaparams are and how much potential there is for
+building systems with these and future ones.
+
+* A bunch of internal API's have been updated. This makes it better for
+function and resource writers! Some GAPI changes also got pushed
+through that make things clearer for those reading code.
+
+* We have a listlookup function. It's still missing syntactic sugar
+though!
+
+* Our new function graph engine is called "dage". I think it's pretty
+clever. There's a chance there is still a bug inside, but it's unclear.
+Please report any issues. If you have some large machines I can test
+very large and fast graphs on, please let me know.
+
+* Lambdas really work now! The txn and ref/gc code is pretty fantastic.
+
+* Many bugs have been killed!
+
+* We're looking for help writing Amazon, Google, DigitalOcean, Hetzner,
+etc, resources if anyone is interested, reach out to us. Particularly
+if there is support from those organizations as well.
+
+* Many other bug fixes, changes, etc...
+
+* See the git log for more NEWS, and for anything notable I left out!
+
+BUGS/TODO
+
+* Function values getting _passed_ to resources doesn't work yet, but
+it's not a blocker, but it would definitely be useful. We're looking
+into it.
+
+* Function graphs are unnecessarily dynamic. We might make them more
+static so that we don't need as many transactions. This is really a
+compiler optimization and not a bug, but it's something important we'd
+like to have.
+
+* Running two Txn's during the same pause would be really helpful. I'm
+not sure how much of a performance improvement we'd get from this, but
+it would sure be interesting to build. If you want to build a fancy
+synchronization primitive, then let us know! Again this is not a bug.
+
+TALKS
+
+I don't have anything planned until CfgMgmtCamp 2024. If you'd like to
+book me for a private event, or sponsor my travel for your conference,
+please let me know.
+
+MISC
+
+We're still looking for new contributors, and there are easy, medium
+and hard issues available! You're also welcome to suggest your own!
+Please join us in #mgmtconfig on Libera IRC or Matrix, or ping this
+list if you'd like help getting started! For details please see:
+
+https://github.com/purpleidea/mgmt/blob/master/docs/faq.md#how-do-i-con
+tribute-to-the-project-if-i-dont-know-golang
+
+Many tagged #mgmtlove issues exist:
+https://github.com/purpleidea/mgmt/issues?q=is%3Aissue+is%3Aopen+label%
+3Amgmtlove
+
+Although asking in IRC/matrix is the best way to find something to work
+on.
+
+MENTORING
+
+We offer mentoring for new golang/mgmt hackers who want to get
+involved. This is fun and friendly! You get to improve your skills,
+and we get some patches in return. Ping me off-list for details.
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest
+release:
+James Shubin, Kaushal, Laurent Indermuehle, Ofek Atar, Samuel Gélineau
+We had 5 unique committers since 0.0.23, and have had 88 overall.
+run 'git log 0.0.23..0.0.24' to see what has changed since 0.0.23
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/0.0.25

@@ -0,0 +1,343 @@
+I've just released version 0.0.25 of mgmt!
+
+> 686 files changed, 28391 insertions(+), 6935 deletions(-)
+
+This is the first release that I consider to be generally useful at
+solving real-world problems, without needing to be an mgmt expert. It's
+also the first release that includes a very real `mcl` codebase. An
+accompanying blog post is also available:
+https://purpleidea.com/blog/2024/03/27/a-new-provisioning-tool/
+
+With that, here are a few highlights from the release:
+
+* We have a new mgmt partner program. Please sign-up for early access
+to these release notes, along with other special privileges. Details
+at: https://bit.ly/mgmt-partner-program
+
+* You can build self-contained mgmt binaries that contain a custom
+application. An initial "provisioning tool" has been built in this way.
+Please see the blog post for more details.
+
+* Default lookup functions exist in the language, with syntactic sugar
+(the || operator) , so you can get a default value if one doesn't
+exist, eg: $some_struct->some_struct_field || "some_default_value".
+
+* Resource fields can now accept interface{} (any) types.
+
+* A panic feature now exists in the language.
+
+* The exec resource has new `donecmd` and `creates` fields. Of note,
+`creates` supports watches too!
+
+* Send/recv now works for autogrouped resources!
+
+* Added `include as` (for classes) to the language. Nested
+(sugar/hierarchical) classes are now supported to make this more
+powerful!
+
+* Stats are printed if the function engine is waiting for too long.
+
+* There's a new http:flag resource, and also an http:proxy resource so
+that we can have caching http proxies!
+
+* Added a firewalld resource for opening ports!
+
+* Added a dhcp:range resource which is very powerful and has a fun API!
+
+* Added the "embedded" and "entry" packages, for building standalone
+tools. This goes perfectly with the new CLI library that we ported
+everything to.
+
+And much more...
+
+
+DOWNLOAD
+
+Prebuilt binaries are available here for this release:
+https://github.com/purpleidea/mgmt/releases/tag/0.0.25
+
+They can also be found on the Fedora mirror:
+https://dl.fedoraproject.org/pub/alt/purpleidea/mgmt/releases/0.0.25/
+
+
+NEWS
+
+* We changed the logical operators in mcl to use well-known English
+tokens: OR, AND, NOT. (but in lowercase of course)
+
+* The history function has been temporarily removed from the syntactic
+core. We'll add it back if we find it's useful to have sugar!
+
+* A bunch of lexer/parser cleanups and improvements were made.
+
+* Default lookup functions for lists, maps, and structs have been
+added. These come with syntactic sugar as mentioned above. (We plan to
+keep this syntax, but we're open to feedback and changes if they're
+good.)
+
+* Resources can accept the interface{} (any) type, although this should
+be used sparingly.
+
+* We added a new mcl test suite that checks resource output too!
+
+* Added a new `value` resource. This is a special resource kind that
+can be used for building some powerful state machines. Recommended for
+experienced users only.
+
+* Improved the golang function generation to allow functions that take
+[]str, so now we have a bunch more functions (like join) in our stdlib
+for free.
+
+* Add some mac address formatting functions. (core/net)
+
+* Added a panic resource and panic function into the core language.
+This is useful for safely shutting down a running mcl program to
+prevent something disastrous or unhandled.
+
+* Added a `donecmd` field to the exec resource. This runs a command
+after a successful CheckApply. This replaces the `&& echo foo > done`
+pattern that you'd see in some code.
+
+* Added a new internal `local` API that can be used for local machine
+operations. So far, read/writing/watching values that are stored
+locally.
+
+* Added `value` functions which bridge the `value` resource via the
+`local` API. To be used sparingly!
+
+* Bumped to golang 1.20, and we'll probably move again before the next
+release.
+
+* Allow send/recv with autogrouped resources. This adds many
+possibilities, in particular with the server style resources.
+
+* Added a bunch of tests for sneaky corner cases. Some of these were
+hard to write, but I think they're worth it.
+
+* ExprBind is now monomorphic! This was a design mistake that we
+introduced, but have since repaired. We now have far fewer copies
+running in the function graph, and things are much more efficient. This
+means lambdas can only have one type when used at two different call
+sites, which is much more logical, safer, faster and memory efficient.
+
+* Added an --only-unify option if you want to test your code but not
+run it.
+
+* Added a concat function for the common case of interpolation. This
+makes type unification significantly faster.
+
+* Eliminated some "benign" races. You might find this commit
+interesting to read: bc63b7608e84f60bf9d568188814d411a0688738
+
+* A pgraph bug was found and fixed. A test was added too! It's amazing
+this was here for so long, it just shows how subtle graph
+datastructures can be.
+
+* Added `include as` (for classes) to the language which lets our
+classes produce values which can then be used elsewhere. I decided this
+feature would be necessary after writing a bunch of mcl. It does have
+an extraneous scoping bug, but not anything that causes problems.
+
+* Nested classes are now supported. This lets you write the equivalent
+of nested classes, without actually having to nest them! This is not
+inheritance, but rather a way of handling scope and passing it
+downwards.
+
+* Improved the Ordering compiler step to catch a bunch of unhandled
+bugs. Sam is a genius and was able to figure out some of these using
+wizardry.
+
+* Added some convert functions to the mcl package.
+
+* Allow edges with colons...
+
+* ...Because we now support a new hierarchical autogrouping algorithm!
+This let's us have some very powerful resources.
+
+* ...Like http:*, dhcp:*, and so on, but we could even go deeper!
+
+* Fixed a super sneaky bug with resource swapping. Due to how we Cmp,
+this now preserves state more often, and in particular when we need it.
+I'm fairly certain that some code in a WIP branch of mine was actually
+blocked because of this issue. Pleased to run into it again, but now
+with a fix in place!
+
+* Added an http:flag resource. This let's a `wget` or similar call back
+to the http:server to kick off an action.
+
+* The http:flag resource supports directories now.
+
+* Stats are printed if the function engine is waiting for too long.
+This is mostly useful for developers who are building new functions and
+have a bug in their midst!
+
+* We added a --skip-unify option to prevent the double unification when
+running locally. When using `mgmt run` to test locally, we type check,
+and then deploy to ourselves, which then naturally type checks again.
+This skips the first one, which would be unsafe generally, but is
+perfectly safe when we're running a single instance.
+
+* Added a new http:proxy resource, and then tweaked it's API, and then
+added http streaming. This is an incredibly powerful resource that lets
+us build a caching http proxy with a single resource. I can't wait to
+see what else it gets used for. I'm using it for provisioning. It's not
+performance optimized at the moment as it uses a single mutex for
+everything, but this could be extended if we wanted to scale this out.
+
+* Added a ton of measuring/timing of common operations. This confirmed
+my belief that autoedges were slower than necessary. There are two ways
+to improve this. We might end up doing either one or both. Autogrouping
+is currently much faster than needed, so no improvements planned for
+now!
+
+* Started to clean up the internal FS API's. It would be really great
+if the core golang team would add something so we could get rid of the
+afero external interfaces.
+
+* Added an "embedded" package to offer API's related to embedded mcl
+programs! This lets us build standalone binaries which are powered by
+mcl.
+
+* Moved to a new CLI (go-arg) library. This has a few downsides, but
+they are fixable upstream, and this vastly improved our code quality
+and API's. This needed to happen, what with the mess that was
+urfave/cli. Look at our diff's, they're really elegant! This let us
+clean up our lib structs as well!
+
+* Added an "entry" package to kick-off the embedded API stuff. This
+uses the new CLI API's that we just built. The end-user now has a
+really easy time building new tools.
+
+* Added a bunch of util functions to aid in building certain standalone
+tools. I'm willing to accept more contributions in this space if
+they're sane, and related to our general mission. Please ask and then
+send patches if you're unsure.
+
+* Added a firewalld resource which makes opening up ports automatic
+when we need them. Perfect for the standalone laptop use-case.
+
+* Made type unification cancellable in case you get into a long-running
+scenario and want to end early.
+
+* Added a `creates` field to the exec resource. Very useful, and also
+supports watches! This is very useful for the common uses of exec.
+
+* Added a dhcp:range resource to offer any number of IP addresses to
+devices that we don't know the mac addresses of in advance. This makes
+building a provisioning tool even more ergonomic.
+
+* Optimized the name invariants since we can usually avoid an exclusive
+invariant in the common case. This roughly halved the type unification
+time. More improvements coming too!
+
+* Caught a sneaky list type that could get through type unification
+when it was interpolated alone. This now enforces the string invariant
+when we specify it, which is an important language design distinction.
+We added tests for this of course too!
+
+* The "log" package has been entirely refactored and is only visible in
+one place at the top of the program. Nice! I have a design for a
+"better logger / user interface" if we ever want to improve on this.
+
+* Added release targets for standalone binary builds. I also improved
+the Makefile release magic significantly.
+
+* Made a lot of small "polish" improvements to various resources.
+
+* Most interestingly, an embedded provisioner application has been
+built and made available in full. Please test and share with others.
+Hopefully this will encourage more interest in the project.
+
+* We're looking for help writing Amazon, Google, DigitalOcean, Hetzner,
+etc, resources if anyone is interested, reach out to us. Particularly
+if there is support from those organizations as well.
+
+* Many other bug fixes, changes, etc...
+
+* See the git log for more NEWS, and for anything notable I left out!
+
+
+BUGS/TODO
+
+* Function values getting _passed_ to resources doesn't work yet, but
+it's not a blocker, but it would definitely be useful. We're looking
+into it.
+
+* Function graphs are unnecessarily dynamic. We might make them more
+static so that we don't need as many transactions. This is really a
+compiler optimization and not a bug, but it's something important we'd
+like to have.
+
+* Running two Txn's during the same pause would be really helpful. I'm
+not sure how much of a performance improvement we'd get from this, but
+it would sure be interesting to build. If you want to build a fancy
+synchronization primitive, then let us know! Again this is not a bug.
+
+* Type unification performance can be improved drastically. I will have
+to implement the fast algorithm so that we can scale to very large mcl
+programs. Help is wanted if you are familiar with "unionfind" and/or
+type unification.
+
+
+TALKS
+
+I don't have anything planned until CfgMgmtCamp 2025. If you'd like to
+book me for a private event, or sponsor my travel for your conference,
+please let me know.
+
+I recently gave two talks: one at CfgMgmtCamp 2024, and one at FOSDEM
+in the golang room. Both are available online and demonstrated an
+earlier version of the provisioning tool which is fully available
+today. The talks can be found here: https://purpleidea.com/talks/
+
+
+PARTNER PROGRAM
+
+We have a new mgmt partner program which gets you early access to
+releases, bug fixes, support, and many other goodies. Please sign-up
+today: https://bit.ly/mgmt-partner-program
+
+
+MISC
+
+Our mailing list host (Red Hat) is no longer letting non-Red Hat
+employees use their infrastructure. We're looking for a new home. I've
+opened a ticket with Freedesktop. If you have any sway with them or
+other recommendations, please let me know:
+https://gitlab.freedesktop.org/freedesktop/freedesktop/-/issues/1082
+
+We're still looking for new contributors, and there are easy, medium
+and hard issues available! You're also welcome to suggest your own!
+Please join us in #mgmtconfig on Libera IRC or Matrix (preferred) and
+ping us if you'd like help getting started! For details please see:
+
+https://github.com/purpleidea/mgmt/blob/master/docs/faq.md#how-do-i-con
+tribute-to-the-project-if-i-dont-know-golang
+
+Many tagged #mgmtlove issues exist:
+https://github.com/purpleidea/mgmt/issues?q=is%3Aissue+is%3Aopen+label%
+3Amgmtlove
+
+Although asking in IRC/matrix is the best way to find something to work
+on.
+
+
+MENTORING
+
+We offer mentoring for new golang/mgmt hackers who want to get
+involved. This is fun and friendly! You get to improve your skills,
+and we get some patches in return. Ping me off-list for details.
+
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest
+release:
+Eng Zer Jun, James Shubin, Oliver Lowe, Samuel Gélineau
+We had 4 unique committers since 0.0.24, and have had 90 overall.
+run 'git log 0.0.24..0.0.25' to see what has changed since 0.0.24
+
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/0.0.26

@@ -0,0 +1,142 @@
+I've just released version 0.0.26 of mgmt!
+
+> 16 files changed, 869 insertions(+), 181 deletions(-)
+
+Hot off the heels of the recent large release (0.0.25) I've just
+released an incremental update...
+
+See more here:
+
+https://purpleidea.com/blog/2024/03/27/a-new-provisioning-tool/
+
+With that, here are a few highlights from the release:
+
+* We have a new mgmt partner program. Please sign-up for early access
+to these release notes, along with other special privileges. Details
+at: https://bit.ly/mgmt-partner-program
+
+* Type unification for the provisioning tool is about 40x faster.
+
+* We fix a small bug related to the upcoming fedora 40 release.
+
+And much more...
+
+
+DOWNLOAD
+
+Prebuilt binaries are available here for this release:
+https://github.com/purpleidea/mgmt/releases/tag/0.0.26
+
+They can also be found on the Fedora mirror:
+https://dl.fedoraproject.org/pub/alt/purpleidea/mgmt/releases/0.0.26/
+
+
+NEWS
+
+* Added old release notes into git
+
+* We now skip over unreleased Fedora versions (like "40 Beta") when
+trying to automatically determine the latest stable release.
+
+* Type unification was structurally refactored to make way for a bunch
+of future improvements and generally to modernize the code.
+
+* Added some unification optimizations and a unification flag
+optimizations system to allow solvers to support special flags. One of
+these new flags was used for the provisioner code with a substantial
+improvement in type unification time by about 40x.
+
+* New cli args are also available for using these flags.
+
+* We're looking for help writing Amazon, Google, DigitalOcean, Hetzner,
+etc, resources if anyone is interested, reach out to us. Particularly
+if there is support from those organizations as well.
+
+* Many other bug fixes, changes, etc...
+
+* See the git log for more NEWS, and for anything notable I left out!
+
+
+BUGS/TODO
+
+* Function values getting _passed_ to resources doesn't work yet, but
+it's not a blocker, but it would definitely be useful. We're looking
+into it.
+
+* Function graphs are unnecessarily dynamic. We might make them more
+static so that we don't need as many transactions. This is really a
+compiler optimization and not a bug, but it's something important we'd
+like to have.
+
+* Running two Txn's during the same pause would be really helpful. I'm
+not sure how much of a performance improvement we'd get from this, but
+it would sure be interesting to build. If you want to build a fancy
+synchronization primitive, then let us know! Again this is not a bug.
+
+* General type unification performance can be improved drastically. I
+will have to implement the fast algorithm so that we can scale to very
+large mcl programs. Help is wanted if you are familiar with "unionfind"
+and/or type unification.
+
+
+TALKS
+
+I don't have anything planned until CfgMgmtCamp 2025. If you'd like to
+book me for a private event, or sponsor my travel for your conference,
+please let me know.
+
+I recently gave two talks: one at CfgMgmtCamp 2024, and one at FOSDEM
+in the golang room. Both are available online and demonstrated an
+earlier version of the provisioning tool which is fully available
+today. The talks can be found here: https://purpleidea.com/talks/
+
+
+PARTNER PROGRAM
+
+We have a new mgmt partner program which gets you early access to
+releases, bug fixes, support, and many other goodies. Please sign-up
+today: https://bit.ly/mgmt-partner-program
+
+
+MISC
+
+Our mailing list host (Red Hat) is no longer letting non-Red Hat
+employees use their infrastructure. We're looking for a new home. I've
+opened a ticket with Freedesktop. If you have any sway with them or
+other recommendations, please let me know:
+https://gitlab.freedesktop.org/freedesktop/freedesktop/-/issues/1082
+
+We're still looking for new contributors, and there are easy, medium
+and hard issues available! You're also welcome to suggest your own!
+Please join us in #mgmtconfig on Libera IRC or Matrix (preferred) and
+ping us if you'd like help getting started! For details please see:
+
+https://github.com/purpleidea/mgmt/blob/master/docs/faq.md#how-do-i-con
+tribute-to-the-project-if-i-dont-know-golang
+
+Many tagged #mgmtlove issues exist:
+https://github.com/purpleidea/mgmt/issues?q=is%3Aissue+is%3Aopen+label%
+3Amgmtlove
+
+Although asking in IRC/matrix is the best way to find something to work
+on.
+
+
+MENTORING
+
+We offer mentoring for new golang/mgmt hackers who want to get
+involved. This is fun and friendly! You get to improve your skills,
+and we get some patches in return. Ping me off-list for details.
+
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest
+release:
+James Shubin
+We had 1 unique committers since 0.0.25, and have had 90 overall.
+
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/0.0.27

@@ -0,0 +1,205 @@
+I've just released version 0.0.27 of mgmt!
+
+> 854 files changed, 28882 insertions(+), 16049 deletions(-)
+
+This is rather large release, as I'm not making regular releases unless there's
+a specific ask. Most folks that are playing with mgmt are using `git master`.
+
+With that, here are a few highlights from the release:
+
+* Type unification is now extremely fast for all scenarios.
+
+* Added a modules/ directory with shared mcl code for everyone to use. This
+includes code for virtualization, cups, shorewall, dhcp, routers, and more!
+
+* New core mgmt commands including setup, firstboot, and docs were added!
+
+* The provisioner got lots of improvements including handoff, and iPXE support.
+
+And much more...
+
+
+DOWNLOAD
+
+Prebuilt binaries are available here for this release:
+https://github.com/purpleidea/mgmt/releases/tag/0.0.27
+
+They can also be found on the Fedora mirror:
+https://dl.fedoraproject.org/pub/alt/purpleidea/mgmt/releases/0.0.27/
+
+
+NEWS
+
+* Primary community channel is now on Matrix. IRC is deprecated until someone
+wants to run a bridge for us.
+
+* Type unification is now textbook, and blazingly (linearly) fast. The large
+programs I'm writing now unify in under 200ms. Most small programs typically
+unify in ~5ms.
+
+* Resource and edge names are always lists of strings now unless they're static.
+
+* We're up to golang 1.23 now. Older versions may still work.
+
+* Our type system now supports unification variables like ?1, ?2 and so on.
+
+* I fixed a bug in my contrib.sh script which omitted the Co-authored-by people!
+This means Samuel Gélineau might have previously been missed in past release
+notes which is tragic, since he has been by far the most important contributor
+to mgmt.
+
+* Made toposort deterministic which fixes some spurious non-determinism.
+
+* Added the iterator filter function. (An important core primitive.)
+
+* Cleaned up the output of many resources to make logs more useful / less noisy.
+
+* Added constants, although I plan to change this to a `const` import package.
+
+* Added the list and map core packages.
+
+* Catch $ in metaparams to make the obvious bug cases easier for users to avoid.
+
+* Consul is now behind a build tag for now, since it's non-free. We'll remove it
+eventually if there isn't a suitable free replacement.
+
+* Added mcl modules directory with a good initial set of interesting code.
+
+* Added the the "vardir" API to our "local" package. This is a helpful primitive
+which I use in almost every module that I write.
+
+* Added a gzip resource!
+
+* Added a tar resource!
+
+* We moved the template() function to the golang.template namespace. This makes
+it clear what kind of template it is and de-emphasizes our "love" for it as the
+blessed template engine at least for now.
+
+* Added a sysctl resource!
+
+* Added a virt-builder resource for building images. We can now automate virtual
+machines really elegantly.
+
+* A bunch of core functions were added including stuff in net, strings, deploy,
+and more!
+
+* The local package got a neat "pool" function. There are lots of possibilities
+to use this in creative ways!
+
+* The GAPI/deploy code got more testing and we found some edge cases and patched
+them. You can now deploy in all sorts of creative ways and things should work
+as expected!
+
+* Added a resource for archiving a deploy. This is deploy:tar and helps with
+bootstrapping new machines.
+
+* Found a sneaky DHCP bug and fixed it!
+
+* Added mgmt setup and firstboot commands! This helps bootstrap things without
+needing to re-implement that logic everywhere as bash too!
+
+* Added a "docs" command for generating resources and function documentation!
+
+* The provisioner got lots of improvements including handoff, and iPXE support.
+
+* New mcl modules include shorewall, dhcp, cups, some meta modules, misc modules
+and more!
+
+* Added a BMC resource in case you want to automate your server hardware.
+
+* We now allow multiple star (*) imports although it's not recommended.
+
+* Hostname handoff is now also part of the provisioner.
+
+* Fixed two type unification corner cases with magic struct functions.
+
+* Added iPXE support to the provisioner.
+
+* Added pprof support to make it easy to generate performance information.
+
+* Added anonymous function calling. These are occasionally useful, and now the
+language has them. They were fun and concise to implement!
+
+* We're looking for help writing Amazon, Google, DigitalOcean, Hetzner, etc,
+resources if anyone is interested, reach out to us. Particularly if there is
+support from those organizations as well.
+
+* Many other bug fixes, changes, etc...
+
+* See the git log for more NEWS, and for anything notable I left out!
+
+
+BUGS/TODO
+
+* Function values getting _passed_ to resources doesn't work yet, but it's not a
+blocker, but it would definitely be useful. We're looking into it.
+
+* Function graphs are unnecessarily dynamic. We might make them more static so
+that we don't need as many transactions. This is really a compiler optimization
+and not a bug, but it's something important we'd like to have.
+
+* Running two Txn's during the same pause would be really helpful. I'm not sure
+how much of a performance improvement we'd get from this, but it would sure be
+interesting to build. If you want to build a fancy synchronization primitive,
+then let us know! Again this is not a bug.
+
+* The arm64 version doesn't support augeas, so it was built with:
+GOTAGS='noaugeas' to get the build out.
+
+
+TALKS
+
+After FOSDEM/CfgMgmtCamp 2025, I don't have anything planned until CfgMgmtCamp
+2026. If you'd like to book me for a private event, or sponsor my travel for
+your conference, please let me know.
+
+
+PARTNER PROGRAM
+
+Interest in the partner program has been limited to small individuals with no
+real corporate backing, so its been officially discontinued for now. If you're
+interested in partnering with us and receiving support, mgmt products early
+access to releases, bug fixes, support, and many other goodies, please sign-up
+today: https://bit.ly/mgmt-partner-program
+
+
+MISC
+
+Our mailing list host (Red Hat) is no longer letting non-Red Hat employees use
+their infrastructure. We're looking for a new home. I've opened a ticket with
+Freedesktop. If you have any sway with them or other recommendations, please let
+me know:
+https://gitlab.freedesktop.org/freedesktop/freedesktop/-/issues/1082
+
+We're still looking for new contributors, and while there are easy, medium and
+hard issues available! You're also welcome to suggest your own! Please join us
+in #mgmtconfig on Libera IRC or Matrix (preferred) and ping us if you'd like
+help getting started! For details please see:
+
+https://github.com/purpleidea/mgmt/blob/master/docs/faq.md#how-do-i-contribute-to-the-project-if-i-dont-know-golang
+
+Many tagged #mgmtlove issues exist:
+https://github.com/purpleidea/mgmt/issues?q=is%3Aissue+is%3Aopen+label%3Amgmtlove
+
+Although asking in matrix is the best way to find something to work on.
+
+
+MENTORING
+
+We offer mentoring for new golang/mgmt hackers who want to get involved. This is
+fun and friendly! You get to improve your skills, and we get some patches in
+return. Ping me off-list for details.
+
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest release:
+Cian Yong Leow, Felix Frank, James Shubin, Joe Groocock, Julian Rüth, Omar Al-Shuha, Samuel Gélineau, xlai89
+We had 8 unique committers since 0.0.26, and have had 96 overall.
+Run 'git log 0.0.26..0.0.27' to see what has changed since 0.0.26
+
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/0.0.9

@@ -0,0 +1,71 @@
+I've just released 0.0.9!
+
+Release tags are now signed with my GPG key.
+
+From now on, I'm going to try and write a release email to the list
+with information about each release. Here we go!
+
+NEWS
+
+* There were far more commits that went into this release than I was
+expecting. I delayed a while because of some nasty races and deadlocks
+I encountered when cleaning some cruft out of the engine.
+
+134 files changed, 5394 insertions(+), 2168 deletions(-)
+
+* We grew initial integration with Prometheus thanks to new contributor
+`roidelapluie`.
+
+* The file resource can now chown/chmod files! Thanks to new
+contributor `mildred`.
+
+* The virt resource can now hotplug/hotunplug cpus. This made for some
+dope demos at CfgMgmtCamp. Special thanks to pkrempa for helping me
+with the libvirt API.
+
+* Native testing of all the golang code is now enabled again. I broke
+this when I split mgmt up into multiple packages. (Sorry!) Golang tests
+in foo_test.go should now run and be tested automatically. I'd
+especially like it if someone wrote some for pgraph/pgraph.go:
+GraphSync().
+
+* Documentation has been significantly improved. We have a resource
+guide (for writing new native resources) and much more. We also now
+build the docs as a RTD project:
+https://mgmt.readthedocs.io/en/master/
+Patches welcome to make it style as pretty as GitHub markdown does.
+
+* See the git log for more NEWS, and sorry for anything notable I left
+out!
+
+BUGS
+
+* I hope to resolve this soon, but it shouldn't block further
+development on git master for now. The issue: if you make extremely
+high speed graph changes to graphs involving the virt resource, it can
+eventually cause a panic. This is being tracked here:
+https://github.com/libvirt/libvirt-go/issues/7 (help welcome!)
+
+GLUSTERFS
+
+I've started working on some stuff for Glusterd so that it can embed
+mgmt as a lib, and use the resource model to simplify cluster
+management. This will involve writing Gluster resources in mgmt
+(volume, brick, etc...) and all sorts of other fun stuff. If you'd like
+to participate, please LMK!
+
+MISC
+
+We're still looking for new contributors, and there are easy, medium and hard issues available! You're also welcome to suggest your own! Please join us in #mgmtconfig on Freenode IRC, or ping this list if you'd like help getting started!
+
+THANKS
+
+We had 12 unique committers since 0.0.8, and have had 29 overall.
+Thanks (alphabetically) to everyone who contributed to the latest
+release: Daniele Sluijters, Daniel P. Berrange, Felix Frank, goberghen,
+James Shubin, Julien Pivotto, Kaushal M, Lars Kulseng, Mildred Ki'Lya,
+Sean Jones, Steve Milner, Tom Ritserveldt.
+
+Happy hacking,
+James
+@purpleidea

docs/release-notes/1.0.0

@@ -0,0 +1,280 @@
+I've just released version 1.0.0 of mgmt!
+
+>  614 files changed, 30199 insertions(+), 11916 deletions(-)
+
+This is very important and large release. It's been 10 years since I first
+publicly released this project, and I might as well stop confusing new users.
+I'm happily using it in production for some time now, and I love writing `mcl`
+every day! I am doing customer work in mgmt, and I have happy users.
+
+With that, here are a few highlights from the release:
+
+* There is a new function engine which is significantly faster on large graphs.
+It could be improved further, but the optimizations aren't needed for now.
+
+* The "automatic embedded etcd clustering" should be considered deprecated. You
+can run with --no-magic to ensure it's off. It was buggy and we will possibly
+write it with mcl anyways. Expect it to be removed soon.
+
+* Type unification errors have context and line numbers! Many other error
+scenarios have this too! This isn't perfect, and there are still some remaining
+places when you don't get this information. Please help us find and expand
+these.
+
+* The function API has been overhauled which now makes writing most functions
+significantly easier and simpler. They'll also use less memory. This is a
+benefit of the new function engine.
+
+* We have added *declarative* for and forkv statements to the language.
+
+* Exported resources are merged and gorgeous! They work how I've always wanted.
+You can actually see my experiment in the very first demo of mgmt, and I finally
+wrote them to work with the language how I've always wanted.
+
+* There's an http:server:ui set of resources that have been added. Check out:
+https://www.youtube.com/watch?v=8vz1MMGkuik for some examples of that in action
+and more!
+
+And much more...
+
+
+SPONSORS
+
+The `mgmt` project is generously sponsored by:
+
+m9rx corporation - https://m9rx.com/
+
+Please reach out if you'd like to sponsor!
+
+
+DOWNLOAD
+
+Prebuilt binaries are available here for this release:
+https://github.com/purpleidea/mgmt/releases/tag/1.0.0
+
+They can also be found on the Fedora mirror:
+https://dl.fedoraproject.org/pub/alt/purpleidea/mgmt/releases/1.0.0/
+
+
+NEWS
+
+* A bunch of misc mcl code has been added to modules/ for you to see.
+
+* The user resource has been improved following feedback from cloudflare.
+
+* Detect self-referential frags when building files that way.
+
+* Added a new function for URL parsing.
+
+* Type unification errors have context and line numbers!
+
+* There's a "baddev" feature branch which gets rebased which you can use if you
+don't want to install the tools to compiler the lexer/parser stuff. We do the
+ugly commit for you if that's easier for development.
+
+* We have added *declarative* for and forkv statements to the language. If you
+know of a better name that "forkv" we're happy to hear it, but a small poll
+didn't produce a more convincing suggestion.
+
+* Waiting for a deploy just happens automatically with the "empty" frontend.
+
+* Waiting to run a deploy just waits automatically until etcd is online.
+
+* Automatic mgmt deploying after virt provisioning works with a seeds field.
+
+* There's a global flag to skip autoedges to improve performance.
+
+* The docker resource has been modernized and supports running on a docker host
+that we're bootstrapping.
+
+* Docker ports were built backwards and these have been corrected.
+
+* The "world" interface has been cleaned up dramatically. This will make life
+easier for someone who wants to add a new backend there. Filesystem, scheduler,
+deployer, and more are all split.
+
+* We can run our etcd connection over SSH. That's one of the new backends.
+There's actually a reconnect issue, but it's an easy fix and it should likely
+come out in the next release.
+
+* We have an is_virtual function to detect where mgmt is running!
+
+* Virtualization modules moved to qcow2 by default. It's solid.
+
+* Improved a lot of user-facing logging so it's clearer what's happening.
+
+* Exported resources have been implemented ... and they're glorious. They work
+how I've always dreamed, and are such a breath of fresh air from the Puppet
+days. There's an export/collect system. Export works by metaparam, not a special
+language feature, and collect works with core functions. It runs when the
+resource in the graph actually runs, as opposed to "all at once, even if you
+fail" like the old days. Yay!
+
+* fmt.printf handles more cases!
+
+* The file resource now has a symlink param. Someone test it and find issues.
+
+* We have an iter.range function which is helpful with `for` statements.
+
+* We do some speculation which drastically reduces the shape of the function
+graphs in a lot of constant scenarios. This also reduces the need to change the
+shape, which brings a huge performance boost.
+
+* Don't reuse fact pointers. There was a bug around those. In fact get rid of
+the fact API since it's pointless really.
+
+* There's some new stuff in the convert package.
+
+* We added an http:server:ui resource. This is kind of a prototype, but you can
+see it in action here: https://www.youtube.com/watch?v=8vz1MMGkuik
+
+* Fix some send/recv corner cases. I wish I had more tests for this. Hint!
+
+* There's an os.readfilewait() function in temporarily. This will go away when
+we get the <|> operator.
+
+* A WatchFiles field was added to the exec resource. Very handy.
+
+* We have a new "line" resource. It supports "trim"-ing too.
+
+* There are some new functions that have been added.
+
+* The modules/ directory got some ssh key things.
+
+* Automatic grouping logic improved, thanks to http:server:ui stuff.
+
+* Hierarchical grouping works very reliably as far as I can tell.
+
+* A bunch of ctx's were added all over where they never were. Legacy code!
+
+* A bunch of network/NetworkManager/networkd and related mcl code was added. The
+interfaces are really ugly, what is the correct upstream network config thing?
+
+* We have a modinfo function.
+
+* We built in some ulimit settings for modern machines.
+
+* We have an mcl class for copr setup.
+
+* We added SSH hostkey logic into our core etcd ssh connection tooling.
+
+* The provisioner supports exec handoff. It can also handle more scenarios, eg
+booting from an ipxe usb key and not installing on it.
+
+* The provisioner supports encrypting machines with LUKS. It does this in a very
+clever way to allow creation of secure passwords after first boot. Many kudos to
+the systemd and other authors who built all the needed pieces for this to just
+work fairly well.
+
+* We improved a graph function from O(n) to O(1). Woops =D
+
+* We removed the secret channels from the function graphs. This is much simpler
+now!
+
+* ExprIf and StmtIf both do the more correct thing. I guess the bigger graph was
+eventually going to need to get killed. This was a good choice that I didn't
+make soon enough.
+
+* A ton of races were killed. We're building by default with the race checker.
+I don't know why I didn't do this ten years ago. Performance is not so terrible
+these days, and it catches so much. Woops. Good lesson to share with others.
+
+* The language has a nil type, but don't worry, this is only for internal
+plumbing, and we will NOT let it be user facing!
+
+* The langpuppet stuff had to be removed again for now. If it's used, patch in.
+
+* The GAPI stuff got a major cleanup. It was early code that was bad. Now it's a
+lot better.
+
+* The new function engine is the really big story. Have a look if you're an
+algorithmist. We'd love to have people work on improving it further. It's most
+likely glitch free now too!
+
+* The virt resource code a big cleanup. It runs hotplug again which had rotted
+due to libvirt api changes I think.
+
+* The qemu guest agent works automatically again.
+
+* The svc resource (one of the earliest) has been overhauled since it had old
+buggy code which has now been fixed.
+
+* We're looking for help writing Amazon, Google, DigitalOcean, Hetzner, etc,
+resources if anyone is interested, reach out to us. Particularly if there is
+support from those organizations as well.
+
+* Many other bug fixes, changes, etc...
+
+* See the git log for more NEWS, and for anything notable I left out!
+
+
+BUGS/TODO
+
+* Function values getting _passed_ to resources doesn't work yet, but it's not a
+blocker, but it would definitely be useful. We're looking into it.
+
+* The arm64 version doesn't support augeas, so it was built with:
+GOTAGS='noaugeas' to get the build out.
+
+* We don't have the <|> operator merged yet. Expect that when we do this, we'll
+consider removing the || (default) operator. This is the only pending language
+change that I know of, and these cases are easily caught by the compiler and can
+be easily patched.
+
+* Autoedge performance isn't great. It can easily be disabled. Most of the time
+I just specify my edges, so this is really a convenience feature, but it should
+be looked into when we have a chance.
+
+* There's a subtle ssh reconnect issue which can occur. It should be easy to
+fix and I have a patch in testing.
+
+* Our wasm code input fields grew tick marks, but I think this disturbed the
+buggy wasm code. If someone is an expert here, please have at it.
+
+
+TALKS
+
+After FOSDEM/CfgMgmtCamp 2026, I don't have anything planned until CfgMgmtCamp
+2027. If you'd like to book me for a private event, or sponsor my travel for
+your conference, please let me know.
+
+
+MISC
+
+Our mailing list host (Red Hat) is no longer letting non-Red Hat employees use
+their infrastructure. We're looking for a new home. I've opened a ticket with
+Freedesktop. If you have any sway with them or other recommendations, please let
+me know:
+https://gitlab.freedesktop.org/freedesktop/freedesktop/-/issues/1082
+
+We're still looking for new contributors, and while there are easy, medium and
+hard issues available! You're also welcome to suggest your own! Please join us
+in #mgmtconfig on Libera IRC or Matrix (preferred) and ping us if you'd like
+help getting started! For details please see:
+
+https://github.com/purpleidea/mgmt/blob/master/docs/faq.md#how-do-i-contribute-to-the-project-if-i-dont-know-golang
+
+Many tagged #mgmtlove issues exist:
+https://github.com/purpleidea/mgmt/issues?q=is%3Aissue+is%3Aopen+label%3Amgmtlove
+
+Although asking in matrix is the best way to find something to work on.
+
+
+MENTORING
+
+We offer mentoring for new golang/mgmt hackers who want to get involved. This is
+fun and friendly! You get to improve your skills, and we get some patches in
+return. Ping me off-list for details.
+
+
+THANKS
+
+Thanks (alphabetically) to everyone who contributed to the latest release:
+Ahmad Abuziad, Edward Toroshchyn, Felix Frank, hades, James Shubin, Karpfen, Lourenço, Lourenço Vales, Samuel Gélineau
+We had 10 unique committers since 0.0.27, and have had 103 overall.
+run 'git log 0.0.27..1.0.0' to see what has changed since 0.0.27
+
+
+Happy hacking,
+James
+@purpleidea

docs/resource-guide.md

@@ -0,0 +1,826 @@
+# Resource guide
+
+## Overview
+
+The `mgmt` tool has built-in resource primitives which make up the building
+blocks of any configuration. Each instance of a resource is mapped to a single
+vertex in the resource [graph](https://en.wikipedia.org/wiki/Directed_acyclic_graph).
+This guide is meant to instruct developers on how to write a brand new resource.
+Since `mgmt` and the core resources are written in golang, some prior golang
+knowledge is assumed.
+
+## Theory
+
+Resources in `mgmt` are similar to resources in other systems in that they are
+[idempotent](https://en.wikipedia.org/wiki/Idempotence). Our resources are
+uniquely different in that they can detect when their state has changed, and as
+a result can run to revert or repair this change instantly. For some background
+on this design, please read the
+[original article](https://purpleidea.com/blog/2016/01/18/next-generation-configuration-mgmt/)
+on the subject.
+
+## Resource Prerequisites
+
+### Imports
+
+You'll need to import a few packages to make writing your resource easier. Here
+is the list:
+
+```
+	"github.com/purpleidea/mgmt/engine"
+	"github.com/purpleidea/mgmt/engine/traits"
+```
+
+The `engine` package contains most of the interfaces and helper functions that
+you'll need to use. The `traits` package contains some base functionality which
+you can use to easily add functionality to your resource without needing to
+implement it from scratch.
+
+### Resource struct
+
+Each resource will implement methods as pointer receivers on a resource struct.
+The naming convention for resources is that they end with a `Res` suffix.
+
+The resource struct should include an anonymous reference to the `Base` trait.
+Other `traits` can be added to the resource to add additional functionality.
+They are discussed below.
+
+You'll most likely want to store a reference to the `*Init` struct type as
+defined by the engine. This is data that the engine will provide to your
+resource on Init.
+
+Lastly you should define the public fields that make up your resource API, as
+well as any private fields that you might want to use throughout your resource.
+Do _not_ depend on global variables, since multiple copies of your resource
+could get instantiated.
+
+You'll want to add struct tags based on the different frontends that you want
+your resources to be able to use. Some frontends can infer this information if
+it is not specified, but others cannot, and some might poorly infer if the
+struct name is ambiguous.
+
+If you'd like your resource to be accessible by the `YAML` graph API (GAPI),
+then you'll need to include the appropriate YAML fields as shown below. This is
+used by the `puppet` compiler as well, so make sure you include these struct
+tags if you want existing `puppet` code to be able to run using the `mgmt`
+engine.
+
+#### Example
+
+```golang
+type FooRes struct {
+	traits.Base // add the base methods without re-implementation
+	traits.Groupable
+	traits.Refreshable
+
+	init *engine.Init
+
+	Whatever string `lang:"whatever" yaml:"whatever"` // you pick!
+	Baz      bool   `lang:"baz" yaml:"baz"`           // something else
+
+	something string // some private field
+}
+```
+
+## Resource API
+
+To implement a resource in `mgmt` it must satisfy the
+[`Res`](https://github.com/purpleidea/mgmt/blob/master/engine/resources.go)
+interface. What follows are each of the method signatures and a description of
+each.
+
+### Default
+
+```golang
+Default() engine.Res
+```
+
+This returns a populated resource struct as a `Res`. It shouldn't populate any
+values which already get a good default as the respective golang zero value. In
+general it is preferable if the zero values make for the correct defaults.
+(This is to say, resources are designed to behave safely and intuitively
+when parameters take a zero value, whenever this is possible.)
+
+#### Example
+
+```golang
+// Default returns some sensible defaults for this resource.
+func (obj *FooRes) Default() engine.Res {
+	return &FooRes{
+		Answer: 42, // sometimes, defaults shouldn't be the zero value
+	}
+}
+```
+
+### Validate
+
+```golang
+Validate() error
+```
+
+This method is used to validate if the populated resource struct is a valid
+representation of the resource kind. If it does not conform to the resource
+specifications, it should return an error. If you notice that this method is
+quite large, it might be an indication that you should reconsider the parameter
+list and interface to this resource. This method is called by the engine
+_before_ `Init`. It can also be called occasionally after a Send/Recv operation
+to verify that the newly populated parameters are valid. Remember not to expect
+access to the outside world when using this.
+
+#### Example
+
+```golang
+// Validate reports any problems with the struct definition.
+func (obj *FooRes) Validate() error {
+	if obj.Answer != 42 { // validate whatever you want
+		return fmt.Errorf("expected an answer of 42")
+	}
+	return nil
+}
+```
+
+### Init
+
+```golang
+Init() error
+```
+
+This is called to initialize the resource. If something goes wrong, it should
+return an error. It should do any resource specific work such as initializing
+channels, sync primitives, or anything else that is relevant to your resource.
+If it is not need throughout, it might be preferable to do some initialization
+and tear down locally in either the Watch method or CheckApply method. The
+choice depends on your particular resource and making the best decision requires
+some experience with mgmt. If you are unsure, feel free to ask an existing
+`mgmt` contributor. During `Init`, the engine will pass your resource a struct
+containing some useful data and pointers. You should save a copy of this pointer
+since you will need to use it in other parts of your resource.
+
+#### Example
+
+```golang
+// Init initializes the Foo resource.
+func (obj *FooRes) Init(init *engine.Init) error
+	obj.init = init // save for later
+
+	// run the resource specific initialization, and error if anything fails
+	if some_error {
+		return err // something went wrong!
+	}
+	return nil
+}
+```
+
+This method is always called after `Validate` has run successfully, with the
+exception that we can't prevent a malicious or buggy `libmgmt` user to not run
+this. In other words, you should expect `Validate` to have run first, but you
+shouldn't allow `Init` to dangerously `rm -rf /$the_world` if your code only
+checks `$the_world` in `Validate`. Remember to always program safely!
+
+### Cleanup
+
+```golang
+Cleanup() error
+```
+
+This is called to cleanup after the resource. It is usually not necessary, but
+can be useful if you'd like to properly close a persistent connection that you
+opened in the `Init` method and were using throughout the resource. It is *not*
+the shutdown signal that tells the resource to exit. That happens in the Watch
+loop.
+
+#### Example
+
+```golang
+// Cleanup is run by the engine to clean up after the resource is done.
+func (obj *FooRes) Cleanup() error {
+	err := obj.conn.Close() // close some internal connection
+	obj.someMap = nil       // free up some large data structure from memory
+	return err
+}
+```
+
+You should probably check the return errors of your internal methods, and pass
+on an error if something went wrong.
+
+### CheckApply
+
+```golang
+CheckApply(ctx context.Context, apply bool) (checkOK bool, err error)
+```
+
+`CheckApply` is where the real _work_ is done. Under normal circumstances, this
+function should check if the state of this resource is correct, and if so, it
+should return: `(true, nil)`. If the `apply` variable is set to `true`, then
+this means that we should then proceed to run the changes required to bring the
+resource into the correct state. If the `apply` variable is set to `false`, then
+the resource is operating in _noop_ mode and _no operational changes_ should be
+made! The ctx should be monitored in case a shutdown has been requested. This
+may be used if a timeout occurred, or if the user shutdown the engine.
+
+After having executed the necessary operations to bring the resource back into
+the desired state, or after having detected that the state was incorrect, but
+that changes can't be made because `apply` is `false`, you should then return
+`(false, nil)`.
+
+You must cause the resource to converge during a single execution of this
+function. If you cannot, then you must return an error! The exception to this
+rule is that if an external force changes the state of the resource while it is
+being remedied, it is possible to return from this function even though the
+resource isn't now converged. This is not a bug, as the resources `Watch`
+facility will detect the new change, ultimately resulting in a subsequent call
+to `CheckApply`.
+
+#### Example
+
+```golang
+// CheckApply does the idempotent work of checking and applying resource state.
+func (obj *FooRes) CheckApply(ctx context.Context, apply bool) (bool, error) {
+	// check the state
+	if state_is_okay { return true, nil } // done early! :)
+
+	// state was bad
+
+	if !apply { return false, nil } // don't apply, we're in noop mode
+
+	if any_error { return false, err } // anytime there's an err!
+
+	// do the apply!
+	return false, nil // after success applying
+}
+```
+
+The `CheckApply` function is called by the `mgmt` engine when it believes a call
+is necessary. Under certain conditions when a `Watch` call does not invalidate
+the state of the resource, and no refresh call was sent, its execution might be
+skipped. This is an engine optimization, and not a bug. It is mentioned here in
+the documentation in case you are confused as to why a debug message you've
+added to the code isn't always printed.
+
+#### Paired execution
+
+For many resources it is not uncommon to see `CheckApply` run twice in rapid
+succession. This is usually not a pathological occurrence, but rather a healthy
+pattern which is a consequence of the event system. When the state of the
+resource is incorrect, `CheckApply` will run to remedy the state. In response to
+having just changed the state, it is usually the case that this repair will
+trigger the `Watch` code! In response, a second `CheckApply` is triggered, which
+will likely find the state to now be correct.
+
+#### Summary
+
+* Anytime an error occurs during `CheckApply`, you should return `(false, err)`.
+* If the state is correct and no changes are needed, return `(true, nil)`.
+* You should only make changes to the system if `apply` is set to `true`.
+* After checking the state and possibly applying the fix, return `(false, nil)`.
+* Returning `(true, err)` is a programming error and can have a negative effect.
+
+### Watch
+
+```golang
+Watch(ctx context.Context) error
+```
+
+`Watch` is a main loop that runs and sends messages when it detects that the
+state of the resource might have changed. To send a message you should write to
+the input event channel using the `Event` helper method. The Watch function
+should run continuously until a shutdown message is received. If at any time
+something goes wrong, you should return an error, and the `mgmt` engine will
+handle possibly restarting the main loop based on the `retry` meta parameter.
+
+It is better to send an event notification which turns out to be spurious, than
+to miss a possible event. Resources which can miss events are incorrect and need
+to be re-engineered so that this isn't the case. If you have an idea for a
+resource which would fit this criteria, but you can't find a solution, please
+contact the `mgmt` maintainers so that this problem can be investigated and a
+possible system level engineering fix can be found.
+
+You may have trouble deciding how much resource state checking should happen in
+the `Watch` loop versus deferring it all to the `CheckApply` method. You may
+want to put some simple fast path checking in `Watch` to avoid generating
+obviously spurious events, but in general it's best to keep the `Watch` method
+as simple as possible. Contact the `mgmt` maintainers if you're not sure.
+
+If the resource is activated in `polling` mode, the `Watch` method will not get
+executed. As a result, the resource must still work even if the main loop is not
+running.
+
+You must make sure to cleanup any running code or goroutines before Watch exits.
+
+#### Select
+
+The lifetime of most resources `Watch` method should be spent in an infinite
+loop that is bounded by a `select` call. The `select` call is the point where
+our method hands back control to the engine (and the kernel) so that we can
+sleep until something of interest wakes us up. In this loop we must wait until
+we get a shutdown event from the engine via the `<-ctx.Done()` channel, which
+closes when we'd like to shut everything down. At this point you should cleanup,
+and let `Watch` close.
+
+#### Events
+
+If the `<-ctx.Done()` channel closes, we should shutdown our resource. When we
+want to send an event, we use the `Event` helper function. This automatically
+marks the resource state as `dirty`. If you're unsure, it's not harmful to send
+the event. This will ultimately cause `CheckApply` to run. This method can block
+if the resource is being paused.
+
+#### Startup
+
+Once the `Watch` function has finished starting up successfully, it is important
+to generate one event to notify the `mgmt` engine that we're now listening
+successfully, so that it can run an initial `CheckApply` to ensure we're safely
+tracking a healthy state and that we didn't miss anything when `Watch` was down
+or from before `mgmt` was running. You must do this by calling the
+`obj.init.Running` method.
+
+#### Converged
+
+The engine might be asked to shutdown when the entire state of the system has
+not seen any changes for some duration of time. The engine can determine this
+automatically, but each resource can block this if it is absolutely necessary.
+If you need this functionality, please contact one of the maintainers and ask
+about adding this feature and improving these docs right here.
+
+This particular facility is most likely not required for most resources. It may
+prove to be useful if a resource wants to start off a long operation, but avoid
+sending out erroneous `Event` messages to keep things alive until it finishes.
+
+#### Example
+
+```golang
+// Watch is the listener and main loop for this resource.
+func (obj *FooRes) Watch(ctx context.Context) error {
+	// setup the Foo resource
+	var err error
+	if err, obj.foo = OpenFoo(); err != nil {
+		return err // we couldn't startup
+	}
+	defer obj.whatever.CloseFoo() // shutdown our Foo
+
+	// notify engine that we're running
+	obj.init.Running() // when started, notify engine that we're running
+
+	for {
+		select {
+		// the actual events!
+		case event := <-obj.foo.Events:
+			if !is_an_event {
+				continue // skip event
+			}
+			// send below...
+
+		// event errors
+		case err := <-obj.foo.Errors:
+			return err // will cause a retry or permanent failure
+
+		case <-ctx.Done(): // signal for shutdown request
+			return nil
+		}
+
+		obj.init.Event() // notify engine of an event (this can block)
+	}
+}
+```
+
+#### Summary
+
+* Remember to call `Running` when the `Watch` is running successfully.
+* Remember to process internal events and shutdown promptly if asked to.
+* Ensure the design of your resource is well thought out.
+* Have a look at the existing resources for a rough idea of how this all works.
+
+### Cmp
+
+```golang
+Cmp(engine.Res) error
+```
+
+Each resource must have a `Cmp` method. It is an abbreviation for `Compare`. It
+takes as input another resource and must return whether they are identical or
+not. This is used for identifying if an existing resource can be used in place
+of a new one with a similar set of parameters. In particular, when switching
+from one graph to a new (possibly identical) graph, this avoids recomputing the
+state for resources which don't change or that are sufficiently similar that
+they don't need to be swapped out.
+
+In general if all the resource properties are identical, then they usually don't
+need to be changed. On occasion, not all of them need to be compared, in
+particular if they store some generated state, or if they aren't significant in
+some way.
+
+If the resource is identical, then you should return `nil`. If it is not, then
+you should return a short error message which gives the reason it differs.
+
+#### Example
+
+```golang
+// Cmp compares two resources and returns if they are equivalent.
+func (obj *FooRes) Cmp(r engine.Res) error {
+	// we can only compare FooRes to others of the same resource kind
+	res, ok := r.(*FooRes)
+	if !ok {
+		return fmt.Errorf("not a %s", obj.Kind())
+	}
+
+	if obj.Whatever != res.Whatever {
+		return fmt.Errorf("the Whatever param differs")
+	}
+	if obj.Flag != res.Flag {
+		return fmt.Errorf("the Flag param differs")
+	}
+
+	return nil // they must match!
+}
+```
+
+## Traits
+
+Resources can have different `traits`, which means they can be extended to have
+additional functionality or special properties. Those special properties are
+usually added by extending your resource so that it is compatible with
+additional interface that contain the `Res` interface. Each of these interfaces
+represents the additional functionality. Since in most cases this requires some
+common boilerplate, you can usually get some or most of the functionality by
+embedding the correct trait struct anonymously in your struct. This is shown in
+the struct example above. You'll always want to include the `Base` trait in all
+resources. This provides some basics which you'll always need.
+
+What follows are a list of available traits.
+
+### Refreshable
+
+Some resources may choose to support receiving refresh notifications. In general
+these should be avoided if possible, but nevertheless, they do make sense in
+certain situations. Resources that support these need to verify if one was sent
+during the CheckApply phase of execution. This is accomplished by calling the
+`obj.init.Refresh() bool` method, and inspecting the return value. This is only
+necessary if you plan to perform a refresh action. Refresh actions should still
+respect the `apply` variable, and no system changes should be made if it is
+`false`. Refresh notifications are generated by any resource when an action is
+applied by that resource and are transmitted through graph edges which have
+enabled their propagation. Resources that currently perform some refresh action
+include `svc`, `timer`, and `password`.
+
+It is very important that you include the `traits.Refreshable` struct in your
+resource. If you do not include this, then calling `obj.init.Refresh` may
+trigger a panic. This is programmer error.
+
+### Edgeable
+
+Edgeable is a trait that allows your resource to automatically connect itself to
+other resources that use this trait to add edge dependencies between the two. An
+older blog post on this topic is
+[available](https://purpleidea.com/blog/2016/03/14/automatic-edges-in-mgmt/).
+
+After you've included this trait, you'll need to implement two methods on your
+resource.
+
+#### UIDs
+
+```golang
+UIDs() []engine.ResUID
+```
+
+The `UIDs` method returns a list of `ResUID` interfaces that represent the
+particular resource uniquely. This is used with the AutoEdges API to determine
+if another resource can match a dependency to this one.
+
+#### AutoEdges
+
+```golang
+AutoEdges() (engine.AutoEdge, error)
+```
+
+This returns a struct that implements the `AutoEdge` interface. This struct
+is used to match other resources that might be relevant dependencies for this
+resource.
+
+### Groupable
+
+Groupable is a trait that can allow your resource automatically group itself to
+other resources. Doing so can reduce the resource or runtime burden on the
+engine, and improve performance in some scenarios. An older blog post on this
+topic is
+[available](https://purpleidea.com/blog/2016/03/30/automatic-grouping-in-mgmt/).
+
+### Sendable
+
+Sendable is a trait that allows your resource to send values through the graph
+edges to another resource. These values are produced during `CheckApply`. They
+can be sent to any resource that has an appropriate parameter and that has the
+`Recvable` trait. You can read more about this in the Send/Recv section below.
+
+### Recvable
+
+Recvable is a trait that allows your resource to receive values through the
+graph edges from another resource. These values are consumed during the
+`CheckApply` phase, and can be detected there as well. They can be received from
+any resource that has an appropriate value and that has the `Sendable` trait.
+You can read more about this in the Send/Recv section below.
+
+### Exportable
+
+Exportable allows a resource to tell the exporter what subset of its data it
+wishes to export when that occurs. It is rare that you will need to use this.
+
+## Resource Initialization
+
+During the resource initialization in `Init`, the engine will pass in a struct
+containing a bunch of data and methods. What follows is a description of each
+one and how it is used.
+
+### Program
+
+Program is a string containing the name of the program. Very few resources need
+this.
+
+### Hostname
+
+Hostname is the uuid for the host. It will be occasionally useful in some
+resources. It is preferable if you can avoid depending on this. It is possible
+that in the future this will be a channel which changes if the local hostname
+changes.
+
+### Running
+
+Running must be called after your watches are all started and ready. It is only
+called from within `Watch`. It is used to notify the engine that you're now
+ready to detect changes.
+
+### Event
+
+Event sends an event notifying the engine of a possible state change. It is
+only called from within `Watch`.
+
+### Refresh
+
+Refresh returns whether the resource received a notification. This flag can be
+used to tell a `svc` to reload, or to perform some state change that wouldn't
+otherwise be noticed by inspection alone. You must implement the `Refreshable`
+trait for this to work. It is only called from within `CheckApply`.
+
+### Send
+
+Send exposes some variables you wish to send via the `Send/Recv` mechanism. You
+must implement the `Sendable` trait for this to work. It is only called from
+within `CheckApply`.
+
+### Recv
+
+Recv provides a map of variables which were sent to this resource via the
+`Send/Recv` mechanism. You must implement the `Recvable` trait for this to work.
+It is only called from within `CheckApply`.
+
+### World
+
+World provides a connection to the outside world. This is most often used for
+communicating with the distributed database. It can be used in `Init`,
+`CheckApply` and `Watch`. Use with discretion and understanding of the internals
+if needed in `Cleanup`.
+
+### VarDir
+
+VarDir is a facility for local storage. It is used to return a path to a
+directory which may be used for temporary storage. It should be cleaned up on
+resource `Cleanup` if the resource would like to delete the contents. The
+resource should not assume that the initial directory is empty, and it should be
+cleaned on `Init` if that is a requirement.
+
+### Debug
+
+Debug signals whether we are running in debugging mode. In this case, we might
+want to log additional messages.
+
+### Logf
+
+Logf is a logging facility which will correctly namespace any messages which you
+wish to pass on. You should use this instead of the log package directly for
+production quality resources.
+
+## Further considerations
+
+There is some additional information that any resource writer will need to know.
+Each issue is listed separately below!
+
+### Resource registration
+
+All resources must be registered with the engine so that they can be found. This
+also ensures they can be encoded and decoded. Make sure to include the following
+code snippet for this to work.
+
+```golang
+func init() { // special golang method that runs once
+	// set your resource kind and struct here (the kind must be lower case)
+	engine.RegisterResource("foo", func() engine.Res { return &FooRes{} })
+}
+```
+
+### YAML Unmarshalling
+
+To support YAML unmarshalling for your resource, you must implement an
+additional method. It is recommended if you want to use your resource with the
+`puppet` compiler.
+
+```golang
+UnmarshalYAML(unmarshal func(interface{}) error) error // optional
+```
+
+This is optional, but recommended for any resource that will have a YAML
+accessible struct. It is not required because to do so would mean that
+third-party or custom resources (such as those someone writes to use with
+`libmgmt`) would have to implement this needlessly.
+
+The signature intentionally matches what is required to satisfy the `go-yaml`
+[Unmarshaler](https://godoc.org/gopkg.in/yaml.v2#Unmarshaler) interface.
+
+#### Example
+
+```golang
+// UnmarshalYAML is the custom unmarshal handler for this struct. It is
+// primarily useful for setting the defaults.
+func (obj *FooRes) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	type rawRes FooRes // indirection to avoid infinite recursion
+
+	def := obj.Default()     // get the default
+	res, ok := def.(*FooRes) // put in the right format
+	if !ok {
+		return fmt.Errorf("could not convert to FooRes")
+	}
+	raw := rawRes(*res) // convert; the defaults go here
+
+	if err := unmarshal(&raw); err != nil {
+		return err
+	}
+
+	*obj = FooRes(raw) // restore from indirection with type conversion!
+	return nil
+}
+```
+
+## Send/Recv
+
+In `mgmt` there is a novel concept called _Send/Recv_. For some background,
+please read the [introductory article](https://purpleidea.com/blog/2016/12/07/sendrecv-in-mgmt/).
+When using this feature, the engine will automatically send the user specified
+value to the intended destination without requiring much resource specific code.
+Any time that one of the destination values is changed, the engine automatically
+marks the resource state as `dirty`. To detect if a particular value was
+received, and if it changed (during this invocation of `CheckApply`) from the
+previous value, you can query the `obj.init.Recv()` method. It will contain a
+`map` of all the keys which can be received on, and the value has a `Changed`
+property which will indicate whether the value was updated on this particular
+`CheckApply` invocation. The type of the sending key must match that of the
+receiving one. This can _only_ be done inside of the `CheckApply` function!
+
+```golang
+// inside CheckApply, probably near the top
+if val, exists := obj.init.Recv()["some_key"]; exists {
+	obj.init.Logf("the some_key param was sent to us from: %s.%s", val.Res, val.Key)
+	if val.Changed {
+		obj.init.Logf("the some_key param was just updated!")
+		// you may want to invalidate some local cache
+	}
+}
+```
+
+A resource can send a value during CheckApply by running the `obj.init.Send()`
+method. It must always send a value if (1) it's not erroring in CheckApply, and
+(2) if the `obj.SendActive()` method inside of CheckApply returns true. It is
+not harmful to run the Send method if CheckApply is going to error, or if
+`obj.SendActive()` returns false, just unnecessary. In the `!apply` case where
+we're running in "noop" mode, and where the state is not correct, then you
+should still attempt to send a value, but it is a bit ambiguous which value to
+send. This behaviour may be specified in the future, but at the moment it's
+mostly inconsequential. At the moment, `obj.SendActive()` is disabled at compile
+time, but can be enabled if you have a legitimate use-case for it.
+
+```golang
+// inside CheckApply, somewhere near the end usually
+if err := obj.init.Send(&ExecSends{ // send the special data structure
+	Output: obj.output,
+	Stdout: obj.stdout,
+	Stderr: obj.stderr,
+}); err != nil {
+	return false, err
+}
+```
+
+You must also implement the `Sends()` method which should return the above
+sending struct with all of the fields containing their default or values. Please
+note, that those fields must have their struct tags set appropriately.
+
+### Safety
+
+Lastly, please note that in order for a resource to send a useful value, even
+when its state is already correct (it may have run earlier for example) then it
+may require the implementation of CheckApply to cache a return value for later
+use. Keep in mind that you should store this securely should there be a chance
+that sensitive info is contained within, and that an untrusted user could put
+malicious data in the cache if you are not careful. It's best to make sure the
+users of your resource are aware of its implementation details here.
+
+## Composite resources
+
+Composite resources are resources which embed one or more existing resources.
+This is useful to prevent code duplication in higher level resource scenarios.
+The best example of this technique can be seen in the `nspawn` resource which
+can be seen to partially embed a `svc` resource, but without its `Watch`.
+Unfortunately no further documentation about this subject has been written. To
+expand this section, please send a patch! Please contact us if you'd like to
+work on a resource that uses this feature, or to add it to an existing one!
+
+## Frequently asked questions
+
+(Send your questions as a patch to this FAQ! I'll review it, merge it, and
+respond by commit with the answer.)
+
+### Can I write resources in a different language?
+
+Currently `golang` is the only supported language for built-in resources. We
+might consider allowing external resources to be imported in the future. This
+will likely require a language that can expose a C-like API, such as `python` or
+`ruby`. Custom `golang` resources are already possible when using mgmt as a lib.
+Higher level resource collections will be possible once the `mgmt` DSL is ready.
+
+### Why does the resource API have `CheckApply` instead of two separate methods?
+
+In an early version we actually had both "parts" as separate methods, namely:
+`StateOK` (Check) and `Apply`, but the [decision](https://github.com/purpleidea/mgmt/commit/58f41eddd9c06b183f889f15d7c97af81b0331cc)
+was made to merge the two into a single method. There are two reasons for this:
+
+1. Many situations would involve the engine running both `Check` and `Apply`. If
+the resource needed to share some state (for efficiency purposes) between the
+two calls, this is much more difficult. A common example is that a resource
+might want to open a connection to `dbus` or `http` to do resource state testing
+and applying. If the methods are combined, there's no need to open and close
+them twice. A counter argument might be that you could open the connection in
+`Init`, and close it in `Cleanup`, however you might not want that open for the
+full lifetime of the resource if you only change state occasionally.
+2. Suppose you came up with a really good reason why you wanted the two methods
+to be separate. It turns out that the current `CheckApply` can wrap this easily.
+It would look approximately like this:
+
+```golang
+func (obj *FooRes) CheckApply(ctx context.Context, apply bool) (bool, error) {
+	// my private split implementation of check and apply
+	if c, err := obj.check(ctx); err != nil {
+		return false, err // we errored
+	} else if c {
+		return true, nil // state was good!
+	}
+
+	if !apply {
+		return false, nil // state needs fixing, but apply is false
+	}
+
+	err := obj.apply(ctx) // errors if failure or unable to apply
+
+	return false, err // always return false, with an optional error
+}
+```
+
+Feel free to use this pattern if you're convinced it's necessary. Alternatively,
+if you think I got the `Res` API wrong and you have an improvement, please let
+us know!
+
+### Why do resources have both a `Cmp` method and an `IFF` (on the UID) method?
+
+The `Cmp()` methods are for determining if two resources are effectively the
+same, which is used to make graph change delta's efficient. This is when we want
+to change from the current running graph to a new graph, but preserve the common
+vertices. Since we want to make this process efficient, we only update the parts
+that are different, and leave everything else alone. This `Cmp()` method can
+tell us if two resources are the same. In case it is not obvious, `cmp` is an
+abbrev. for compare.
+
+The `IFF()` method is part of the whole UID system, which is for discerning if a
+resource meets the requirements another expects for an automatic edge. This is
+because the automatic edge system assumes a unified UID pattern to test for
+equality. In the future it might be helpful or sane to merge the two similar
+comparison functions although for now they are separate because they are
+actually answer different questions.
+
+### What new resource primitives need writing?
+
+There are still many ideas for new resources that haven't been written yet. If
+you'd like to contribute one, please contact us and tell us about your idea!
+
+### Is the resource API stable? Does it ever change?
+
+Since we are pre 1.0, the resource API is not guaranteed to be stable, however
+it is not expected to change significantly. The last major change kept the
+core functionality nearly identical, simplified the implementation of all the
+resources, and took about five to ten minutes to port each resource to the new
+API. The fundamental logic and behaviour behind the resource API has not changed
+since it was initially introduced.
+
+### Where can I find more information about mgmt?
+
+Additional blog posts, videos and other material [is available!](https://github.com/purpleidea/mgmt/blob/master/docs/on-the-web.md).
+
+## Suggestions
+
+If you have any ideas for API changes or other improvements to resource writing,
+please let us know! We're still pre 1.0 and pre 0.1 and happy to break API in
+order to get it right!

docs/resources.md

@@ -0,0 +1,250 @@
+# Resources
+
+Here we list all the built-in resources and their properties. The resource
+primitives in `mgmt` are typically more powerful than resources in other
+configuration management systems because they can be event based which lets them
+respond in real-time to converge to the desired state. This property allows you
+to build more complex resources that you probably hadn't considered in the past.
+
+In addition to the resource specific properties, there are resource properties
+(otherwise known as parameters) which can apply to every resource. These are
+called [meta parameters](documentation.md#meta-parameters) and are listed
+separately. Certain meta parameters aren't very useful when combined with
+certain resources, but in general, it should be fairly obvious, such as when
+combining the `noop` meta parameter with the [Noop](#Noop) resource.
+
+You might want to look at the [generated documentation](https://godoc.org/github.com/purpleidea/mgmt/engine/resources)
+for more up-to-date information about these resources.
+
+* [Augeas](#Augeas): Manipulate files using augeas.
+* [Consul:KV](#ConsulKV): Set keys in a Consul datastore.
+* [Docker](#Docker):[Container](#Container) Manage docker containers.
+* [Exec](#Exec): Execute shell commands on the system.
+* [File](#File): Manage files and directories.
+* [Group](#Group): Manage system groups.
+* [Hostname](#Hostname): Manages the hostname on the system.
+* [KV](#KV): Set a key value pair in our shared world database.
+* [Msg](#Msg): Send log messages.
+* [Net](#Net): Manage a local network interface.
+* [Noop](#Noop): A simple resource that does nothing.
+* [Nspawn](#Nspawn): Manage systemd-machined nspawn containers.
+* [Password](#Password): Create random password strings.
+* [Pkg](#Pkg):  Manage system packages with PackageKit.
+* [Print](#Print): Print messages to the console.
+* [Svc](#Svc): Manage system systemd services.
+* [Test](#Test): A mostly harmless resource that is used for internal testing.
+* [Tftp:File](#TftpFile): Add files to the small embedded embedded tftp server.
+* [Tftp:Server](#TftpServer): Run a small embedded tftp server.
+* [Timer](#Timer): Manage system systemd services.
+* [User](#User): Manage system users.
+* [Virt](#Virt): Manage virtual machines with libvirt.
+
+## Augeas
+
+The augeas resource uses [augeas](http://augeas.net/) commands to manipulate
+files.
+
+## Docker
+
+### Container
+
+The docker:container resource manages docker containers.
+
+It has the following properties:
+
+* `state`: either `running`, `stopped`, or `removed`
+* `image`: docker `image` or `image:tag`
+* `cmd`: a command or list of commands to run on the container
+* `env`: a list of environment variables, e.g. `["VAR=val",],`
+* `ports`: a map of portmappings, e.g. `{"tcp" => {8080 => 80, 8443 => 443,},},`
+* `apiversion:` override the host's default docker version, e.g. `"v1.35"`
+* `force`: destroy and rebuild the container instead of erroring on wrong image
+
+## Exec
+
+The exec resource can execute commands on your system.
+
+## File
+
+The file resource manages files and directories. In `mgmt`, directories are
+identified by a trailing slash in their path name. File have no such slash.
+
+It has the following properties:
+
+* `path`: absolute file path (directories have a trailing slash here)
+* `state`: either `exists`, `absent`, or undefined
+* `content`: raw file content
+* `mode`: octal unix file permissions or symbolic string
+* `owner`: username or uid for the file owner
+* `group`: group name or gid for the file group
+
+### Path
+
+The path property specifies the file or directory that we are managing.
+
+### State
+
+The state property describes the action we'd like to apply for the resource. The
+possible values are: `exists` and `absent`. If you do not specify either of
+these, it is undefined. Without specifying this value as `exists`, another param
+cannot cause a file to get implicitly created. When specifying this value as
+`absent`, you should not specify any other params that would normally change the
+file. For example, if you specify `content` and this param is `absent`, then you
+will get an engine validation error.
+
+### Content
+
+The content property is a string that specifies the desired file contents.
+
+### Source
+
+The source property points to a source file or directory path that we wish to
+copy over and use as the desired contents for our resource.
+
+### Fragments
+
+The fragments property lets you specify a list of files to concatenate together
+to make up the contents of this file. They will be combined in the order that
+they are listed in. If one of the files specified is a directory, then the
+files in that top-level directory will be themselves combined together and used.
+
+### Recurse
+
+The recurse property limits whether file resource operations should recurse into
+and monitor directory contents with a depth greater than one.
+
+### Force
+
+The force property is required if we want the file resource to be able to change
+a file into a directory or vice-versa. If such a change is needed, but the force
+property is not set to `true`, then this file resource will error.
+
+### Purge
+
+The purge property is used when this file represents a directory, and we'd like
+to remove any unmanaged files from within it. Please note that any unmanaged
+files in a directory with this flag set will be irreversibly deleted.
+
+## Group
+
+The group resource manages the system groups from `/etc/group`.
+
+## Hostname
+
+The hostname resource manages static, transient/dynamic and pretty hostnames
+on the system and watches them for changes.
+
+### static_hostname
+
+The static hostname is the one configured in /etc/hostname or a similar
+file.
+It is chosen by the local user. It is not always in sync with the current
+host name as returned by the gethostname() system call.
+
+### transient_hostname
+
+The transient / dynamic hostname is the one configured via the kernel's
+sethostbyname().
+It can be different from the static hostname in case DHCP or mDNS have been
+configured to change the name based on network information.
+
+### pretty_hostname
+
+The pretty hostname is a free-form UTF8 host name for presentation to the user.
+
+### hostname
+
+Hostname is the fallback value for all 3 fields above, if only `hostname` is
+specified, it will set all 3 fields to this value.
+
+## KV
+
+The KV resource sets a key and value pair in the global world database. This is
+quite useful for setting a flag after a number of resources have run. It will
+ignore database updates to the value that are greater in compare order than the
+requested key if the `SkipLessThan` parameter is set to true. If we receive a
+refresh, then the stored value will be reset to the requested value even if the
+stored value is greater.
+
+### Key
+
+The string key used to store the key.
+
+### Value
+
+The string value to set. This can also be set via Send/Recv.
+
+### SkipLessThan
+
+If this parameter is set to `true`, then it will ignore updating the value as
+long as the database versions are greater than the requested value. The compare
+operation used is based on the `SkipCmpStyle` parameter.
+
+### SkipCmpStyle
+
+By default this converts the string values to integers and compares them as you
+would expect.
+
+## Msg
+
+The msg resource sends messages to the main log, or an external service such
+as systemd's journal.
+
+## Net
+
+The net resource manages a local network interface using netlink.
+
+## Noop
+
+The noop resource does absolutely nothing. It does have some utility in testing
+`mgmt` and also as a placeholder in the resource graph.
+
+## Nspawn
+
+The nspawn resource is used to manage systemd-machined style containers.
+
+## Password
+
+The password resource can generate a random string to be used as a password. It
+will re-generate the password if it receives a refresh notification.
+
+## Pkg
+
+The pkg resource is used to manage system packages. This resource works on many
+different distributions because it uses the underlying packagekit facility which
+supports different backends for different environments. This ensures that we
+have great Debian (deb/dpkg) and Fedora (rpm/dnf) support simultaneously.
+
+## Print
+
+The print resource prints messages to the console.
+
+## Svc
+
+The service resource is still very WIP. Please help us by improving it!
+
+## Test
+
+The test resource is mostly harmless and is used for internal tests.
+
+## Tftp:File
+
+This adds files to the running tftp server. It's useful because it allows you to
+add individual files without needing to create them on disk.
+
+## Tftp:Server
+
+Run a small embedded tftp server. This doesn't apply any state, but instead runs
+a pure golang tftp server in the Watch loop.
+
+## Timer
+
+This resource needs better documentation. Please help us by improving it!
+
+## User
+
+The user resource manages the system users from `/etc/passwd`.
+
+## Virt
+
+The virt resource can manage virtual machines via libvirt.

docs/service-guide.md

@@ -0,0 +1,145 @@
+# Service API design guide
+
+This document is intended as a short instructional design guide in building a
+service management API. It is certainly intended for someone who wishes to use
+`mgmt` resources and functions to interact with their facilities, however it may
+be of more general use as well. Hopefully this will help you make smarter design
+considerations early on, and prevent some amount of unnecessary technical debt.
+
+## Main aspects
+
+What follows are some of the most common considerations which you may wish to
+take into account when building your service. This list is non-exhaustive. Of
+particular note, as of the writing of this document, many of these designs are
+not taken into account or not well-handled or implemented by the major API
+("cloud") providers.
+
+### Authentication
+
+#### The status-quo
+
+Many services naturally require you to authenticate yourself. Usually the
+initial user who sets up the account and provides credit card details will need
+to download secret credentials in order to access the service. The onus is on
+the user to keep those credentials private, and to prevent leaking them. It is
+convenient (and insecure) to store them in `git` repositories containing scripts
+and configuration management code. Since it's likely you will use multiple
+different services, it also means you will have a ton of different credentials
+to guard.
+
+#### An alternative
+
+Instead, build your service to accept a public key that you store in the users
+account. Only consumers that can correctly sign messages matching this public
+key should be authorized. This mechanism is well-understood by anyone who has
+ever uploaded their public SSH key to a server. You can use SSH keys, GPG keys,
+or even get into Kerberos if that's appropriate. Best of all, if you and other
+services use a standardized mechanism like GPG, a user might only need to keep
+track of their single key-pair, even when they're using multiple services!
+
+### Events
+
+#### The problem
+
+People have been building "[CRUD](https://en.wikipedia.org/wiki/Create,_read,_update_and_delete)"
+and "[REST](https://en.wikipedia.org/wiki/REST)"ful API's for years. The biggest
+missing part that most of them don't provide is events. If users want to know
+when a resource changes, they have to repeatedly poll the server, which is both
+network intensive, and introduces latency. When services were simpler, this
+wasn't as much of a consideration, but these days it matters. An embarrassingly
+small number of major software vendors implement these correctly, if at all.
+
+#### Why events?
+
+The `mgmt` tool is different from most other static tools in that it allows
+reading streams of incoming data, and stream of change events from resources we
+are managing. If an event API is not available, we can still poll, but this is
+not as desirable. An event-capable API doesn't prevent polling if that's
+preferred, you can always repeat a read request periodically.
+
+#### Variants
+
+The two common mechanisms for receiving events are "callbacks" and
+"long-polling". In the former, the service contacts the consumer when something
+happens. In the latter, the consumer opens a connection, and the service either
+closes the connection or sends the reply, when it's ready. Long-polling is often
+preferred since it doesn't require an open firewall on the consumers side.
+Callbacks are preferred because it's often cheaper for the service to implement
+that. It's also less reliable since it's hard to know if the callback message
+wasn't received because it was dropped, or if there just wasn't an event. And it
+requires static timeouts when retrying a callback message, and so on. It's best
+to implement long-polling or something equivalent at a minimum.
+
+#### "Since" requests
+
+When making an event request, some API's will let you tack on a "since" style
+parameter that tells the endpoint that we're interested in all of the events
+_since_ a particular timestamp, or _since_ a particular sequence ID. This can be
+very useful if missing an intermediate event is a concern. Implement this if you
+can, but it's better for all concerned if purely declarative facilities are all
+that is required. It also forces the endpoint to maintain some state, which may
+be undesirable for them.
+
+#### Out of band
+
+Some providers have the event system tacked on to a separate facility. If it's
+not part of the core API, then it's not useful. You shouldn't have to configure
+a separate system in order to start getting events.
+
+### Batching
+
+With so many resources, you might expect to have 1000's of long-polling
+connections all sitting open and idle. That can't be efficient! It's not, which
+is why good API's need a batching facility. This lets the consumer group
+together many watches (all waiting on a long-poll) inside of a single call. That
+way, a single connection might only be needed for a large amount of information.
+
+### Don't auto-generate junk
+
+Please build an elegant API. Many services auto-generate a "phone book" SDK of
+junk. It might seem inevitable, so if you absolutely need to do this, then put
+some extra effort into making it idiomatic. If I'm using an SDK generated for
+`golang` and I see an internal `foo.String` wrapper, then chances are you have
+designed your API and code to be easier to maintain for you, instead of
+prioritizing your customers. Surely the total volume of all customer code is
+more than your own, so why optimize for that instead of the putting the customer
+first?
+
+### Resources and functions
+
+`Mgmt` has a concept of "resources" and "functions". Resources are used in an
+idempotent model to express desired state and perform that work, and "functions"
+are used to receive and pull data into the system. That separation has shown to
+be an elegant one. Consider it when designing your API's. For example, if some
+vital information can only be obtained after performing a modifying operation,
+then it might signal that you're missing some sort of a lookup or event-log
+system. Design your API's to be idempotent, this solves many distributed-system
+problems involving receiving duplicate messages, and so on.
+
+## Using mgmt as a library
+
+Instead of building a new service from scratch, and re-inventing the typical
+management and CLI layer, consider using `mgmt` as a library, and directly
+benefiting from that work. This has not been done for a large production
+service, but the author believes it would be quite efficient, particularly if
+your application is written in golang. It's equivalently easy to do it for other
+languages as well, you just end up with two binaries instead of one. (Or you can
+embed the other binary into the new golang management tool.)
+
+## Cloud API considerations
+
+Many "cloud" companies have a lot of technical debt and a lot of customers. As a
+result, it might be very hard for them to improve their API's, particularly
+without breaking compatibility promises for their existing customers. As a
+result, they should either add a versioned API, which lets newer consumers get
+the benefit, or add new parallel services which offer the modern features. If
+they don't, the only solution is for new competitors to build in these better
+efficiencies, eventually offering better value to cost ratios, which will then
+make legacy products less lucrative and therefore unmaintainable as compared to
+their competitors.
+
+## Suggestions
+
+If you have any ideas for suggestions or other improvements to this guide,
+please let us know! I hope this was helpful. Please reach out if you are
+building an API that you might like to have `mgmt` consume!

docs/style-guide.md

@@ -0,0 +1,283 @@
+# Style guide
+
+This document aims to be a reference for the desired style for patches to mgmt,
+and the associated `mcl` language. In particular it describes conventions which
+are not officially enforced by tools and in test cases, or that aren't clearly
+defined elsewhere. We try to turn as many of these into automated tests as we
+can. If something here is not defined in a test, or you think it should be,
+please write one! Even better, you can write a tool to automatically fix it,
+since this is more useful and can easily be turned into a test!
+
+## Overview for golang code
+
+Most style issues are enforced by the `gofmt` tool. Other style aspects are
+often common sense to seasoned programmers, and we hope this will be a useful
+reference for new programmers.
+
+There are a lot of useful code review comments described
+[here](https://github.com/golang/go/wiki/CodeReviewComments). We don't
+necessarily follow everything strictly, but it is in general a very good guide.
+
+### Basics
+
+* All of our golang code is formatted with `gofmt`.
+
+### Comments
+
+All of our code is commented with the minimums required for `godoc` to function,
+and so that our comments pass `golint`. Code comments should either be full
+sentences (which end with a period, use proper punctuation, and capitalize the
+first word when it is not a lower cased identifier), or are short one-line
+comments in the source which are not full sentences and don't end with a period.
+
+They should explain algorithms, describe non-obvious behaviour, or situations
+which would otherwise need explanation or additional research during a code
+review. Notes about use of unfamiliar API's is a good idea for a code comment.
+
+#### Example
+
+Here you can see a function with the correct `godoc` string. The first word must
+match the name of the function. It is _not_ capitalized because the function is
+private.
+
+```golang
+// square multiplies the input integer by itself and returns this product.
+func square(x int) int {
+	return x * x // we don't care about overflow errors
+}
+```
+
+### Line length
+
+In general we try to stick to 80 character lines when it is appropriate. It is
+almost *always* appropriate for function `godoc` comments and most longer
+paragraphs. Exceptions are always allowed based on the will of the maintainer.
+
+It is usually better to exceed 80 characters than to break code unnecessarily.
+If your code often exceeds 80 characters, it might be an indication that it
+needs refactoring.
+
+Occasionally inline, two line source code comments are used within a function.
+These should usually be balanced so that you don't have one line with 78
+characters and the second with only four. Split the comment between the two.
+
+### Default values
+
+Whenever a constant or function parameter is defined, try and have the safer or
+default value be the `zero` value. For example, instead of `const NoDanger`, use
+`const AllowDanger` so that the `false` value is the safe scenario.
+
+### Method receiver pointers
+
+You almost always want any method receivers to be declared on the pointer to the
+struct. There are only a few rare situations where this is not the case. This
+makes it easier to merge future changes that mutate the state without wondering
+why you now have two different copies of a struct. When you do need to copy a
+a struct, you can add a `Copy()` method to it. It's true that in many situations
+adding the pointer adds a small performance penalty, but we haven't found them
+to be significant in practice. If you do have a performance sensitive patch
+which benefits from skipping the pointer, please demonstrate this need with
+data first.
+
+#### Example
+
+```golang
+type Foo struct {
+	Whatever string
+	// ...
+}
+
+// Bar is implemented correctly as a pointer on Foo.
+func (obj *Foo) Bar(baz string) int {
+	// ...
+}
+
+// Bar is implemented *incorrectly* without a pointer to Foo.
+func (obj Foo) Bar(baz string) int {
+	// ...
+}
+```
+
+### Method receiver naming
+
+[Contrary](https://github.com/golang/go/wiki/CodeReviewComments#receiver-names)
+to the specialized naming of the method receiver variable, we usually name all
+of these `obj` for ease of code copying throughout the project, and for faster
+identification when reviewing code. Some anecdotal studies have shown that it
+makes the code easier to read since you don't need to remember the name of the
+method receiver variable in each different method. This is very similar to what
+is done in `python`.
+
+#### Example
+
+```golang
+// Bar does a thing, and returns the number of baz results found in our
+database.
+func (obj *Foo) Bar(baz string) int {
+	if len(obj.s) > 0 {
+		return strings.Count(obj.s, baz)
+	}
+	return -1
+}
+```
+
+### Variable naming
+
+We prefer shorter, scoped variables rather than `unnecessarilyLongIdentifiers`.
+Remember the scoping rules and feel free to use new variables where appropriate.
+For example, in a short string snippet you can use `s` instead of `myString`, as
+well as other common choices. `i` is a common `int` counter, `f` for files, `fn`
+for functions, `x` for something else and so on.
+
+### Variable reuse
+
+Feel free to create and use new variables instead of attempting to reuse the
+same string. For example, if a function input arg is named `s`, you can use a
+new variable to receive the first computation result on `s` instead of storing
+it back into the original `s`. This avoids confusion if a different part of the
+code wants to read the original input, and it avoids any chance of edit by
+reference of the original callers copy of the variable.
+
+#### Example
+
+```golang
+MyNotIdealFunc(s string, b bool) string {
+	if !b {
+		return s + "hey"
+	}
+	s = strings.Replace(s, "blah", "", -1) // not ideal (reuse of `s` var)
+	return s
+}
+
+MyOkayFunc(s string, b bool) string {
+	if !b {
+		return s + "hey"
+	}
+	s2 := strings.Replace(s, "blah", "", -1) // doesn't reuse `s` variable
+	return s2
+}
+
+MyGreatFunc(s string, b bool) string {
+	if !b {
+		return s + "hey"
+	}
+	return strings.Replace(s, "blah", "", -1) // even cleaner
+}
+```
+
+### Constants in code
+
+If a function takes a specifier (often a bool) it's sometimes better to name
+that variable (often with a `const`) rather than leaving a naked `bool` in the
+code. For example, `x := MyFoo("blah", false)` is less clear than
+`const useMagic = false; x := MyFoo("blah", useMagic)`.
+
+### Empty slice declarations
+
+When declaring a new empty slice, there are three different mechanisms:
+
+1. `a := []string{}`
+
+2. `var a []string`
+
+3. `a := make([]string, 0)`
+
+In general, we prefer the first method because we find that it is succinct, and
+very readable. The third method is the least recommended because you're adding
+extra data that a smart compiler could probably figure out on its own. There are
+performance implications between these three methods, so unless your code is in
+a fast path or memory constrained environment where this matters (and that you
+ideally have proof of this) please use the methods as ordered as much as
+possible.
+
+### Consistent ordering
+
+In general we try to preserve a logical ordering in source files which usually
+matches the common order of execution that a _lazy evaluator_ would follow.
+
+This is also the order which is recommended when creating interface types. When
+implementing an interface, arrange your methods in the same order that they are
+declared in the interface.
+
+When implementing code for the various types in the language, please follow this
+order: `bool`, `str`, `int`, `float`, `list`, `map`, `struct`, `func`.
+
+For other aspects where you have a set of items, try to be internally consistent
+as well. For example, if you have two switch statements with `A`, `B`, and `C`,
+please use the same ordering for these elements elsewhere that they appear in
+the code and in the commentary if it is not illogical to do so.
+
+### Product identifiers
+
+Try to avoid references in the code to `mgmt` or a specific program name string
+if possible. This makes it easier to rename code if we ever pick a better name
+or support `libmgmt` better if we embed it. You can use the `Program` variable
+which is available in numerous places if you want a string to put in the logs.
+
+It is also recommended to avoid the `go` (programming language name) string if
+possible. Try to use `golang` if required, since the word `go` is already
+overloaded, and in particular it was even already used by the
+[`go!`](https://en.wikipedia.org/wiki/Go!_(programming_language)).
+
+## Overview for mcl code
+
+The `mcl` language is quite new, so this guide will probably change over time as
+we find what's best, and hopefully we'll be able to add an `mclfmt` tool in the
+future so that less of this needs to be documented. (Patches welcome!)
+
+### Indentation
+
+Code indentation is done with tabs. The tab-width is a private preference, which
+is the beauty of using tabs: you can have your own personal preference. The
+inventor of `mgmt` uses and recommends a width of eight, and that is what should
+be used if your tool requires a modeline to be publicly committed.
+
+### Line length
+
+We recommend you stick to 80 char line width. If you find yourself with deeper
+nesting, it might be a hint that your code could be refactored in a more
+pleasant way.
+
+### Capitalization
+
+At the moment, variables, function names, and classes are all lowercase and do
+not contain underscores. We will probably figure out what style to recommend
+when the language is a bit further along. For example, we haven't decided if we
+should have a notion of public and private variables, and if we'd like to
+reserve capitalization for this situation.
+
+### Module naming
+
+We recommend you name your modules with an `mgmt-` prefix. For example, a module
+about bananas might be named `mgmt-banana`. This is helpful for the useful magic
+built-in to the module import code, which will by default take a remote import
+like: `import "https://github.com/purpleidea/mgmt-banana/"` and namespace it as
+`banana`. Of course you can always pick the namespace yourself on import with:
+`import "https://github.com/purpleidea/mgmt-banana/" as tomato` or something
+similar.
+
+### Imports
+
+When importing "golang" modules such as "golang/strings" it's recommended to use
+the `import "golang/strings" as golang_strings` format. This is to avoid
+confusion with the normal core package you get from `import "strings"`.
+
+In the long-term, we expect to remove the `"golang/"` namespace when our own
+standard library is complete enough.
+
+### Licensing
+
+We believe that sharing code helps reduce unnecessary re-invention, so that we
+can [stand on the shoulders of giants](https://en.wikipedia.org/wiki/Standing_on_the_shoulders_of_giants)
+and hopefully make faster progress in science, medicine, exploration, etc... As
+a result, we recommend releasing your modules under the [LGPLv3+](https://www.gnu.org/licenses/lgpl-3.0.en.html)
+license for the maximum balance of freedom and re-usability. We strongly oppose
+any [CLA](https://en.wikipedia.org/wiki/Contributor_License_Agreement)
+requirements and believe that the ["inbound==outbound"](https://ref.fedorapeople.org/fontana-linuxcon.html#slide2)
+rule applies. Lastly, we do not support software patents and we hope you don't
+either!
+
+## Suggestions
+
+If you have any ideas for suggestions or other improvements to this guide,
+please let us know!

docs/util/metadata.go

@@ -0,0 +1,103 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+// Package util handles metadata for documentation generation.
+package util
+
+import (
+	"fmt"
+)
+
+var (
+	registeredResourceMetadata = make(map[string]*Metadata) // must initialize
+	registeredFunctionMetadata = make(map[string]*Metadata) // must initialize
+)
+
+// RegisterResource records the metadata for a resource of this kind.
+func RegisterResource(kind string, metadata *Metadata) error {
+	if _, exists := registeredResourceMetadata[kind]; exists {
+		return fmt.Errorf("metadata kind %s is already registered", kind)
+	}
+
+	registeredResourceMetadata[kind] = metadata
+
+	return nil
+}
+
+// LookupResource looks up the metadata for a resource of this kind.
+func LookupResource(kind string) (*Metadata, error) {
+	metadata, exists := registeredResourceMetadata[kind]
+	if !exists {
+		return nil, fmt.Errorf("not found")
+	}
+	return metadata, nil
+}
+
+// RegisterFunction records the metadata for a function of this name.
+func RegisterFunction(name string, metadata *Metadata) error {
+	if _, exists := registeredFunctionMetadata[name]; exists {
+		return fmt.Errorf("metadata named %s is already registered", name)
+	}
+
+	registeredFunctionMetadata[name] = metadata
+
+	return nil
+}
+
+// LookupFunction looks up the metadata for a function of this name.
+func LookupFunction(name string) (*Metadata, error) {
+	metadata, exists := registeredFunctionMetadata[name]
+	if !exists {
+		return nil, fmt.Errorf("not found")
+	}
+	return metadata, nil
+}
+
+// Metadata stores some additional information about the function or resource.
+// This is used to automatically generate documentation.
+type Metadata struct {
+	// Filename is the filename (without any base dir path) that this is in.
+	Filename string
+
+	// Typename is the string name of the main resource struct or function.
+	Typename string
+}
+
+// GetMetadata returns some metadata about the func. It can be called at any
+// time. This must not be named the same as the struct it's on or using it as an
+// anonymous embedded struct will stop us from being able to call this method.
+func (obj *Metadata) GetMetadata() *Metadata {
+	//if obj == nil { // TODO: Do I need this?
+	//	return nil
+	//}
+	return &Metadata{
+		Filename: obj.Filename,
+		Typename: obj.Typename,
+	}
+}

engine/autoedge.go

@@ -0,0 +1,138 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+package engine
+
+import (
+	"fmt"
+)
+
+// EdgeableRes is the interface a resource must implement to support automatic
+// edges. Both the vertices involved in an edge need to implement this for it to
+// be able to work.
+type EdgeableRes interface {
+	Res // implement everything in Res but add the additional requirements
+
+	// AutoEdgeMeta lets you get or set meta params for the automatic edges
+	// trait.
+	AutoEdgeMeta() *AutoEdgeMeta
+
+	// SetAutoEdgeMeta lets you set all of the meta params for the automatic
+	// edges trait in a single call.
+	SetAutoEdgeMeta(*AutoEdgeMeta)
+
+	// UIDs includes all params to make a unique identification of this
+	// object.
+	UIDs() []ResUID // most resources only return one
+
+	// AutoEdges returns a struct that implements the AutoEdge interface.
+	// This interface can be used to generate automatic edges to other
+	// resources.
+	AutoEdges() (AutoEdge, error)
+}
+
+// AutoEdgeMeta provides some parameters specific to automatic edges.
+// TODO: currently this only supports disabling the feature per-resource, but in
+// the future you could conceivably have some small pattern to control it better
+type AutoEdgeMeta struct {
+	// Disabled specifies that automatic edges should be disabled for this
+	// resource.
+	Disabled bool
+}
+
+// Cmp compares two AutoEdgeMeta structs and determines if they're equivalent.
+func (obj *AutoEdgeMeta) Cmp(aem *AutoEdgeMeta) error {
+	if obj.Disabled != aem.Disabled {
+		return fmt.Errorf("values for Disabled are different")
+	}
+	return nil
+}
+
+// The AutoEdge interface is used to implement the autoedges feature.
+type AutoEdge interface {
+	Next() []ResUID   // call to get list of edges to add
+	Test([]bool) bool // call until false
+}
+
+// ResUID is a unique identifier for a resource, namely it's name, and the kind
+// ("type").
+type ResUID interface {
+	fmt.Stringer // String() string
+
+	GetName() string
+	GetKind() string
+
+	IFF(ResUID) bool
+
+	IsReversed() bool // true means this resource happens before the generator
+}
+
+// The BaseUID struct is used to provide a unique resource identifier.
+type BaseUID struct {
+	Name string // name and kind are the values of where this is coming from
+	Kind string
+
+	Reversed *bool // piggyback edge information here
+}
+
+// GetName returns the name of the resource UID.
+func (obj *BaseUID) GetName() string {
+	return obj.Name
+}
+
+// GetKind returns the kind of the resource UID.
+func (obj *BaseUID) GetKind() string {
+	return obj.Kind
+}
+
+// String returns the canonical string representation for a resource UID.
+func (obj *BaseUID) String() string {
+	return fmt.Sprintf("%s[%s]", obj.GetKind(), obj.GetName())
+}
+
+// IFF looks at two UID's and if and only if they are equivalent, returns true.
+// If they are not equivalent, it returns false. Most resources will want to
+// override this method, since it does the important work of actually discerning
+// if two resources are identical in function.
+func (obj *BaseUID) IFF(uid ResUID) bool {
+	res, ok := uid.(*BaseUID)
+	if !ok {
+		return false
+	}
+	return obj.Name == res.Name
+}
+
+// IsReversed is part of the ResUID interface, and true means this resource
+// happens before the generator.
+func (obj *BaseUID) IsReversed() bool {
+	if obj.Reversed == nil {
+		panic("programming error!")
+	}
+	return *obj.Reversed
+}

engine/autoedge_test.go

@@ -0,0 +1,50 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+//go:build !root
+
+package engine
+
+import (
+	"testing"
+)
+
+func TestIFF1(t *testing.T) {
+	uid := &BaseUID{Name: "/tmp/unit-test"}
+	same := &BaseUID{Name: "/tmp/unit-test"}
+	diff := &BaseUID{Name: "/tmp/other-file"}
+
+	if !uid.IFF(same) {
+		t.Errorf("basic resource UIDs with the same name should satisfy each other's IFF condition")
+	}
+
+	if uid.IFF(diff) {
+		t.Errorf("basic resource UIDs with different names should NOT satisfy each other's IFF condition")
+	}
+}

engine/autogroup.go

@@ -0,0 +1,108 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+package engine
+
+import (
+	"fmt"
+
+	"github.com/purpleidea/mgmt/pgraph"
+)
+
+// GroupableRes is the interface a resource must implement to support automatic
+// grouping. Default implementations for most of the methods declared in this
+// interface can be obtained for your resource by anonymously adding the
+// traits.Groupable struct to your resource implementation.
+type GroupableRes interface {
+	Res // implement everything in Res but add the additional requirements
+
+	// AutoGroupMeta lets you get or set meta params for the automatic
+	// grouping trait.
+	AutoGroupMeta() *AutoGroupMeta
+
+	// SetAutoGroupMeta lets you set all of the meta params for the
+	// automatic grouping trait in a single call.
+	SetAutoGroupMeta(*AutoGroupMeta)
+
+	// GroupCmp compares two resources and decides if they're suitable for
+	// grouping. This usually needs to be unique to your resource.
+	GroupCmp(res GroupableRes) error
+
+	// GroupRes groups resource argument (res) into self. Callers of this
+	// method should probably also run SetParent.
+	GroupRes(res GroupableRes) error
+
+	// IsGrouped determines if we are grouped.
+	IsGrouped() bool // am I grouped?
+
+	// SetGrouped sets a flag to tell if we are grouped.
+	SetGrouped(bool)
+
+	// GetGroup returns everyone grouped inside me.
+	GetGroup() []GroupableRes // return everyone grouped inside me
+
+	// SetGroup sets the grouped resources into me. Callers of this method
+	// should probably also run SetParent.
+	SetGroup([]GroupableRes)
+
+	// Parent returns the parent groupable resource that I am inside of.
+	Parent() GroupableRes
+
+	// SetParent tells a particular grouped resource who their parent is.
+	SetParent(res GroupableRes)
+}
+
+// AutoGroupMeta provides some parameters specific to automatic grouping.
+// TODO: currently this only supports disabling the feature per-resource, but in
+// the future you could conceivably have some small pattern to control it better
+type AutoGroupMeta struct {
+	// Disabled specifies that automatic grouping should be disabled for
+	// this resource.
+	Disabled bool
+}
+
+// Cmp compares two AutoGroupMeta structs and determines if they're equivalent.
+func (obj *AutoGroupMeta) Cmp(agm *AutoGroupMeta) error {
+	if obj.Disabled != agm.Disabled {
+		return fmt.Errorf("values for Disabled are different")
+	}
+	return nil
+}
+
+// AutoGrouper is the required interface to implement an autogrouping algorithm.
+type AutoGrouper interface {
+	// listed in the order these are typically called in...
+	Name() string                                                    // friendly identifier
+	Init(*pgraph.Graph) error                                        // only call once
+	VertexNext() (pgraph.Vertex, pgraph.Vertex, error)               // mostly algorithmic
+	VertexCmp(pgraph.Vertex, pgraph.Vertex) error                    // can we merge these ?
+	VertexMerge(pgraph.Vertex, pgraph.Vertex) (pgraph.Vertex, error) // vertex merge fn to use
+	EdgeMerge(pgraph.Edge, pgraph.Edge) pgraph.Edge                  // edge merge fn to use
+	VertexTest(bool) (bool, error)                                   // call until false
+}

engine/cmp.go

@@ -0,0 +1,449 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+package engine
+
+import (
+	"fmt"
+
+	"github.com/purpleidea/mgmt/pgraph"
+	"github.com/purpleidea/mgmt/util/errwrap"
+)
+
+// ResCmp compares two resources by checking multiple aspects. This is the main
+// entry point for running all the compare steps on two resources. This code is
+// very similar to AdaptCmp.
+func ResCmp(r1, r2 Res) error {
+	if r1.Kind() != r2.Kind() {
+		return fmt.Errorf("kind differs")
+	}
+	if r1.Name() != r2.Name() {
+		return fmt.Errorf("name differs")
+	}
+
+	if err := r1.Cmp(r2); err != nil {
+		return err
+	}
+
+	// TODO: do we need to compare other traits/metaparams?
+
+	m1 := r1.MetaParams()
+	m2 := r2.MetaParams()
+	if (m1 == nil) != (m2 == nil) { // xor
+		return fmt.Errorf("meta params differ")
+	}
+	if m1 != nil && m2 != nil {
+		if err := m1.Cmp(m2); err != nil {
+			return err
+		}
+	}
+
+	r1x, ok1 := r1.(RefreshableRes)
+	r2x, ok2 := r2.(RefreshableRes)
+	if ok1 != ok2 {
+		return fmt.Errorf("refreshable differs") // they must be different (optional)
+	}
+	if ok1 && ok2 {
+		if r1x.Refresh() != r2x.Refresh() {
+			return fmt.Errorf("refresh differs")
+		}
+	}
+
+	// compare meta params for resources with auto edges
+	r1e, ok1 := r1.(EdgeableRes)
+	r2e, ok2 := r2.(EdgeableRes)
+	if ok1 != ok2 {
+		return fmt.Errorf("edgeable differs") // they must be different (optional)
+	}
+	if ok1 && ok2 {
+		if r1e.AutoEdgeMeta().Cmp(r2e.AutoEdgeMeta()) != nil {
+			return fmt.Errorf("autoedge differs")
+		}
+	}
+
+	// compare meta params for resources with auto grouping
+	r1g, ok1 := r1.(GroupableRes)
+	r2g, ok2 := r2.(GroupableRes)
+	if ok1 != ok2 {
+		return fmt.Errorf("groupable differs") // they must be different (optional)
+	}
+	if ok1 && ok2 {
+		if r1g.AutoGroupMeta().Cmp(r2g.AutoGroupMeta()) != nil {
+			return fmt.Errorf("autogroup differs")
+		}
+
+		// if resources are grouped, are the groups the same?
+		if i, j := r1g.GetGroup(), r2g.GetGroup(); len(i) != len(j) {
+			return fmt.Errorf("autogroup groups differ")
+		} else if len(i) > 0 { // trick the golinter
+
+			// Sort works with Res, so convert the lists to that
+			iRes := []Res{}
+			for _, r := range i {
+				res := r.(Res)
+				iRes = append(iRes, res)
+			}
+			jRes := []Res{}
+			for _, r := range j {
+				res := r.(Res)
+				jRes = append(jRes, res)
+			}
+
+			ix, jx := Sort(iRes), Sort(jRes) // now sort :)
+			for k := range ix {
+				// compare sub resources
+				if err := ResCmp(ix[k], jx[k]); err != nil {
+					//fmt.Printf("bad Cmp: %+v <> %+v for: %+v <> %+v err: %+v\n", r1, r2, ix[k], jx[k], err)
+					return err
+				}
+			}
+		}
+	}
+
+	r1r, ok1 := r1.(RecvableRes)
+	r2r, ok2 := r2.(RecvableRes)
+	if ok1 != ok2 {
+		return fmt.Errorf("recvable differs") // they must be different (optional)
+	}
+	if ok1 && ok2 {
+		v1 := r1r.Recv()
+		v2 := r2r.Recv()
+
+		// XXX: Our Send/Recv in the lib/main.go doesn't seem to be
+		// pulling this in, so this always compares differently. We can
+		// comment it out for now, since it's not too consequential.
+		// XXX: Find out what the issue is and fix it for here and send.
+		// XXX: The below errors are commented out until this is fixed.
+		if (v1 == nil) != (v2 == nil) { // xor
+			//return fmt.Errorf("recv params differ")
+		}
+		if v1 != nil && v2 != nil {
+			if len(v1) != len(v2) {
+				//return fmt.Errorf("recv param lengths differ")
+			}
+			for key, send1 := range v1 { // map[string]*engine.Send
+				send2, exists := v2[key]
+				if !exists {
+					//return fmt.Errorf("recv param key %s doesn't exist", key)
+				}
+				if (send1 == nil) != (send2 == nil) { // xor
+					//return fmt.Errorf("recv param key %s send differs", key)
+				}
+				if send1 != nil && send2 != nil && send1.Key != send2.Key {
+					//return fmt.Errorf("recv param key %s send key differs (%v != %v)", key, send1.Key, send2.Key)
+				}
+			}
+		}
+	}
+
+	r1s, ok1 := r1.(SendableRes)
+	r2s, ok2 := r2.(SendableRes)
+	if ok1 != ok2 {
+		return fmt.Errorf("sendable differs") // they must be different (optional)
+	}
+	if ok1 && ok2 {
+		s1 := r1s.Sent()
+		s2 := r2s.Sent()
+
+		// XXX: Our Send/Recv in the lib/main.go doesn't seem to be
+		// pulling this in, so this always compares differently. We can
+		// comment it out for now, since it's not too consequential.
+		// XXX: Find out what the issue is and fix it for here and recv.
+		// XXX: The below errors are commented out until this is fixed.
+		if (s1 == nil) != (s2 == nil) { // xor
+			//return fmt.Errorf("send params differ")
+		}
+		if s1 != nil && s2 != nil {
+			// TODO: reflect.DeepEqual?
+			//return fmt.Errorf("send params exist")
+		}
+	}
+
+	// compare meta params for resources with reversible traits
+	r1v, ok1 := r1.(ReversibleRes)
+	r2v, ok2 := r2.(ReversibleRes)
+	if ok1 != ok2 {
+		return fmt.Errorf("reversible differs") // they must be different (optional)
+	}
+	if ok1 && ok2 {
+		if r1v.ReversibleMeta().Cmp(r2v.ReversibleMeta()) != nil {
+			return fmt.Errorf("reversible differs")
+		}
+	}
+
+	return nil
+}
+
+// AdaptCmp compares two resources by checking multiple aspects. This is the
+// main entry point for running all the compatible compare steps on two
+// resources. This code is very similar to ResCmp.
+func AdaptCmp(r1, r2 CompatibleRes) error {
+	if r1.Kind() != r2.Kind() {
+		return fmt.Errorf("kind differs")
+	}
+	if r1.Name() != r2.Name() {
+		return fmt.Errorf("name differs")
+	}
+
+	// run `Adapts` instead of `Cmp`
+	if err := r1.Adapts(r2); err != nil {
+		return err
+	}
+
+	// TODO: do we need to compare other traits/metaparams?
+
+	m1 := r1.MetaParams()
+	m2 := r2.MetaParams()
+	if (m1 == nil) != (m2 == nil) { // xor
+		return fmt.Errorf("meta params differ")
+	}
+	if m1 != nil && m2 != nil {
+		if err := m1.Cmp(m2); err != nil {
+			return err
+		}
+	}
+
+	// we don't need to compare refresh, since those can always be merged...
+
+	// compare meta params for resources with auto edges
+	r1e, ok1 := r1.(EdgeableRes)
+	r2e, ok2 := r2.(EdgeableRes)
+	if ok1 != ok2 {
+		return fmt.Errorf("edgeable differs") // they must be different (optional)
+	}
+	if ok1 && ok2 {
+		if r1e.AutoEdgeMeta().Cmp(r2e.AutoEdgeMeta()) != nil {
+			return fmt.Errorf("autoedge differs")
+		}
+	}
+
+	// compare meta params for resources with auto grouping
+	r1g, ok1 := r1.(GroupableRes)
+	r2g, ok2 := r2.(GroupableRes)
+	if ok1 != ok2 {
+		return fmt.Errorf("groupable differs") // they must be different (optional)
+	}
+	if ok1 && ok2 {
+		if r1g.AutoGroupMeta().Cmp(r2g.AutoGroupMeta()) != nil {
+			return fmt.Errorf("autogroup differs")
+		}
+
+		// if resources are grouped, are the groups the same?
+		if i, j := r1g.GetGroup(), r2g.GetGroup(); len(i) != len(j) {
+			return fmt.Errorf("autogroup groups differ")
+		} else if len(i) > 0 { // trick the golinter
+
+			// Sort works with Res, so convert the lists to that
+			iRes := []Res{}
+			for _, r := range i {
+				res := r.(Res)
+				iRes = append(iRes, res)
+			}
+			jRes := []Res{}
+			for _, r := range j {
+				res := r.(Res)
+				jRes = append(jRes, res)
+			}
+
+			ix, jx := Sort(iRes), Sort(jRes) // now sort :)
+			for k := range ix {
+				// compare sub resources
+				// TODO: should we use AdaptCmp here?
+				// TODO: how would they run `Merge` ? (we don't)
+				// this code path will probably not run, because
+				// it is called in the lang before autogrouping!
+				if err := ResCmp(ix[k], jx[k]); err != nil {
+					return err
+				}
+			}
+		}
+	}
+
+	r1r, ok1 := r1.(RecvableRes)
+	r2r, ok2 := r2.(RecvableRes)
+	if ok1 != ok2 {
+		return fmt.Errorf("recvable differs") // they must be different (optional)
+	}
+	if ok1 && ok2 {
+		v1 := r1r.Recv()
+		v2 := r2r.Recv()
+
+		// XXX: Our Send/Recv in the lib/main.go doesn't seem to be
+		// pulling this in, so this always compares differently. We can
+		// comment it out for now, since it's not too consequential.
+		// XXX: Find out what the issue is and fix it for here and send.
+		// XXX: The below errors are commented out until this is fixed.
+		if (v1 == nil) != (v2 == nil) { // xor
+			//return fmt.Errorf("recv params differ")
+		}
+		if v1 != nil && v2 != nil {
+			if len(v1) != len(v2) {
+				//return fmt.Errorf("recv param lengths differ")
+			}
+			for key, send1 := range v1 { // map[string]*engine.Send
+				send2, exists := v2[key]
+				if !exists {
+					//return fmt.Errorf("recv param key %s doesn't exist", key)
+				}
+				if (send1 == nil) != (send2 == nil) { // xor
+					//return fmt.Errorf("recv param key %s send differs", key)
+				}
+				if send1 != nil && send2 != nil && send1.Key != send2.Key {
+					//return fmt.Errorf("recv param key %s send key differs (%v != %v)", key, send1.Key, send2.Key)
+				}
+			}
+		}
+	}
+
+	r1s, ok1 := r1.(SendableRes)
+	r2s, ok2 := r2.(SendableRes)
+	if ok1 != ok2 {
+		return fmt.Errorf("sendable differs") // they must be different (optional)
+	}
+	if ok1 && ok2 {
+		s1 := r1s.Sent()
+		s2 := r2s.Sent()
+
+		// XXX: Our Send/Recv in the lib/main.go doesn't seem to be
+		// pulling this in, so this always compares differently. We can
+		// comment it out for now, since it's not too consequential.
+		// XXX: Find out what the issue is and fix it for here and recv.
+		// XXX: The below errors are commented out until this is fixed.
+		if (s1 == nil) != (s2 == nil) { // xor
+			//return fmt.Errorf("send params differ")
+		}
+		if s1 != nil && s2 != nil {
+			// TODO: reflect.DeepEqual?
+			//return fmt.Errorf("send params exist")
+		}
+	}
+
+	// compare meta params for resources with reversible traits
+	r1v, ok1 := r1.(ReversibleRes)
+	r2v, ok2 := r2.(ReversibleRes)
+	if ok1 != ok2 {
+		return fmt.Errorf("reversible differs") // they must be different (optional)
+	}
+	if ok1 && ok2 {
+		if r1v.ReversibleMeta().Cmp(r2v.ReversibleMeta()) != nil {
+			return fmt.Errorf("reversible differs")
+		}
+	}
+
+	return nil
+}
+
+// VertexCmpFn returns if two vertices are equivalent. It errors if they can't
+// be compared because one is not a vertex. This returns true if equal.
+// TODO: shouldn't the first argument be an `error` instead?
+func VertexCmpFn(v1, v2 pgraph.Vertex) (bool, error) {
+	r1, ok := v1.(Res)
+	if !ok {
+		return false, fmt.Errorf("v1 is not a Res")
+	}
+	r2, ok := v2.(Res)
+	if !ok {
+		return false, fmt.Errorf("v2 is not a Res")
+	}
+
+	if err := ResCmp(r1, r2); err != nil {
+		//fmt.Printf("bad Cmp: %p %+v <> %p %+v err: %+v\n", r1, r1, r2, r2, err)
+		return false, nil
+	}
+	//fmt.Printf("ok Cmp: %p %+v <> %p %+v\n", r1, r1, r2, r2)
+
+	return true, nil
+}
+
+// EdgeCmpFn returns if two edges are equivalent. It errors if they can't be
+// compared because one is not an edge. This returns true if equal.
+// TODO: shouldn't the first argument be an `error` instead?
+func EdgeCmpFn(e1, e2 pgraph.Edge) (bool, error) {
+	edge1, ok := e1.(*Edge)
+	if !ok {
+		return false, fmt.Errorf("e1 is not an Edge")
+	}
+	edge2, ok := e2.(*Edge)
+	if !ok {
+		return false, fmt.Errorf("e2 is not an Edge")
+	}
+	return edge1.Cmp(edge2) == nil, nil
+}
+
+// ResGraphMapper compares two graphs, and gives us a mapping from new to old
+// based on the resource kind and name only. This allows us to know which
+// previous resource might have data to pass on to the new version in the next
+// generation.
+// FIXME: Optimize this for performance since it runs a lot...
+func ResGraphMapper(oldGraph, newGraph *pgraph.Graph) (map[RecvableRes]RecvableRes, error) {
+	mapper := make(map[RecvableRes]RecvableRes) // new -> old based on name and kind only?
+	cmp := func(r1, r2 Res) error {
+		if r1.Kind() != r2.Kind() {
+			return fmt.Errorf("kind differs")
+		}
+		if r1.Name() != r2.Name() {
+			return fmt.Errorf("name differs")
+		}
+		return nil
+	}
+
+	// XXX: run this as a topological sort or reverse topological sort?
+	for v := range newGraph.Adjacency() { // loop through the vertices (resources)
+		r, ok := v.(RecvableRes)
+		if !ok {
+			continue // skip
+		}
+		fn := func(vv pgraph.Vertex) (bool, error) {
+			rr, ok := vv.(Res)
+			if !ok {
+				return false, fmt.Errorf("not a Res")
+			}
+
+			if err := cmp(rr, r); err != nil {
+				return false, nil
+			}
+			return true, nil
+		}
+		vertex, err := oldGraph.VertexMatchFn(fn)
+		if err != nil {
+			return nil, errwrap.Wrapf(err, "VertexMatchFn failed")
+		}
+		if vertex == nil {
+			continue // skip (error?)
+		}
+		res, ok := vertex.(RecvableRes)
+		if !ok {
+			continue // skip (error?)
+		}
+
+		mapper[r] = res
+	}
+
+	return mapper, nil
+}

engine/copy.go

@@ -0,0 +1,183 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+package engine
+
+import (
+	"fmt"
+
+	"github.com/purpleidea/mgmt/util/errwrap"
+)
+
+// ResCopy copies a resource. This is the main entry point for copying a
+// resource since it does all the common engine-level copying as well.
+func ResCopy(r CopyableRes) (CopyableRes, error) {
+	res := r.Copy()
+	res.SetKind(r.Kind())
+	res.SetName(r.Name())
+
+	if x, ok := r.(MetaRes); ok {
+		dst, ok := res.(MetaRes)
+		if !ok {
+			// programming error
+			panic("meta interfaces are illogical")
+		}
+		dst.SetMetaParams(x.MetaParams().Copy()) // copy b/c we have it
+	}
+
+	if x, ok := r.(RefreshableRes); ok {
+		dst, ok := res.(RefreshableRes)
+		if !ok {
+			// programming error
+			panic("refresh interfaces are illogical")
+		}
+		dst.SetRefresh(x.Refresh()) // no need to copy atm
+	}
+
+	// copy meta params for resources with auto edges
+	if x, ok := r.(EdgeableRes); ok {
+		dst, ok := res.(EdgeableRes)
+		if !ok {
+			// programming error
+			panic("autoedge interfaces are illogical")
+		}
+		dst.SetAutoEdgeMeta(x.AutoEdgeMeta()) // no need to copy atm
+	}
+
+	// copy meta params for resources with auto grouping
+	if x, ok := r.(GroupableRes); ok {
+		dst, ok := res.(GroupableRes)
+		if !ok {
+			// programming error
+			panic("autogroup interfaces are illogical")
+		}
+		dst.SetAutoGroupMeta(x.AutoGroupMeta()) // no need to copy atm
+
+		grouped := []GroupableRes{}
+		for _, g := range x.GetGroup() {
+			g0, ok := g.(CopyableRes)
+			if !ok {
+				return nil, fmt.Errorf("resource wasn't copyable")
+			}
+			g1, err := ResCopy(g0)
+			if err != nil {
+				return nil, err
+			}
+			g2, ok := g1.(GroupableRes)
+			if !ok {
+				return nil, fmt.Errorf("resource wasn't groupable")
+			}
+			g2.SetParent(dst) // store who my parent is
+			grouped = append(grouped, g2)
+		}
+		dst.SetGroup(grouped)
+	}
+
+	if x, ok := r.(RecvableRes); ok {
+		dst, ok := res.(RecvableRes)
+		if !ok {
+			// programming error
+			panic("recv interfaces are illogical")
+		}
+		dst.SetRecv(x.Recv()) // no need to copy atm
+	}
+
+	if x, ok := r.(SendableRes); ok {
+		dst, ok := res.(SendableRes)
+		if !ok {
+			// programming error
+			panic("send interfaces are illogical")
+		}
+		if err := dst.Send(x.Sent()); err != nil { // no need to copy atm
+			return nil, errwrap.Wrapf(err, "can't copy send")
+		}
+	}
+
+	// copy meta params for resources with reversible traits
+	if x, ok := r.(ReversibleRes); ok {
+		dst, ok := res.(ReversibleRes)
+		if !ok {
+			// programming error
+			panic("reversible interfaces are illogical")
+		}
+		dst.SetReversibleMeta(x.ReversibleMeta()) // no need to copy atm
+	}
+
+	return res, nil
+}
+
+// ResMerge merges a set of resources that are compatible with each other. This
+// is the main entry point for the merging. They must each successfully be able
+// to run AdaptCmp without error.
+func ResMerge(r ...CompatibleRes) (CompatibleRes, error) {
+	if len(r) == 0 {
+		return nil, fmt.Errorf("zero resources given")
+	}
+	if len(r) == 1 {
+		return r[0], nil
+	}
+	if len(r) > 2 {
+		r0 := r[0]
+		r1, err := ResMerge(r[1:]...)
+		if err != nil {
+			return nil, err
+		}
+		return ResMerge(r0, r1)
+	}
+	// now we have r[0] and r[1] to merge here...
+	r0 := r[0]
+	r1 := r[1]
+	if err := AdaptCmp(r0, r1); err != nil {
+		return nil, err
+	}
+
+	res, err := r0.Merge(r1) // resource method of this interface
+	if err != nil {
+		return nil, err
+	}
+
+	// meta should have come over in the copy
+
+	if x, ok := res.(RefreshableRes); ok {
+		x0, ok0 := r0.(RefreshableRes)
+		x1, ok1 := r1.(RefreshableRes)
+		if !ok0 || !ok1 {
+			// programming error
+			panic("refresh interfaces are illogical")
+		}
+
+		x.SetRefresh(x0.Refresh() || x1.Refresh()) // true if either is!
+	}
+
+	// the other traits and metaparams can't be merged easily... so we don't
+	// merge them, and if they were present and differed, and weren't copied
+	// in the ResCopy method, then we should have errored above in AdaptCmp!
+
+	return res, nil
+}

engine/doc.go

@@ -0,0 +1,33 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+// Package engine represents the implementation of the resource engine that runs
+// the graph of resources in real-time. This package has the common imports that
+// most consumers use directly.
+package engine

engine/edge.go

@@ -0,0 +1,72 @@
+// Mgmt
+// Copyright (C) James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+// Additional permission under GNU GPL version 3 section 7
+//
+// If you modify this program, or any covered work, by linking or combining it
+// with embedded mcl code and modules (and that the embedded mcl code and
+// modules which link with this program, contain a copy of their source code in
+// the authoritative form) containing parts covered by the terms of any other
+// license, the licensors of this program grant you additional permission to
+// convey the resulting work. Furthermore, the licensors of this program grant
+// the original author, James Shubin, additional permission to update this
+// additional permission if he deems it necessary to achieve the goals of this
+// additional permission.
+
+package engine
+
+import (
+	"fmt"
+)
+
+// Edge is a struct that represents a graph's edge.
+type Edge struct {
+	Name   string
+	Notify bool // should we send a refresh notification along this edge?
+
+	refresh bool // is there a notify pending for the dest vertex ?
+}
+
+// String is a required method of the Edge interface that we must fulfill.
+func (obj *Edge) String() string {
+	return obj.Name
+}
+
+// Cmp compares this edge to another. It returns nil if they are equivalent.
+func (obj *Edge) Cmp(edge *Edge) error {
+	if obj.Name != edge.Name {
+		return fmt.Errorf("edge names differ")
+	}
+	if obj.Notify != edge.Notify {
+		return fmt.Errorf("notify values differ")
+	}
+	// FIXME: should we compare this as well?
+	//if obj.refresh != edge.refresh {
+	//	return fmt.Errorf("refresh values differ")
+	//}
+	return nil
+}
+
+// Refresh returns the pending refresh status of this edge.
+func (obj *Edge) Refresh() bool {
+	return obj.refresh
+}
+
+// SetRefresh sets the pending refresh status of this edge.
+func (obj *Edge) SetRefresh(b bool) {
+	obj.refresh = b
+}