lang: Initial implementation of the mgmt language
This is an initial implementation of the mgmt language. It is a declarative (immutable) functional, reactive, domain specific programming language. It is intended to be a language that is: * safe * powerful * easy to reason about With these properties, we hope this language, and the mgmt engine will allow you to model the real-time systems that you'd like to automate. This also includes a number of other associated changes. Sorry for the large size of this patch.
This commit is contained in:
James Shubin
3
.github/PULL_REQUEST_TEMPLATE.md
vendored
3
.github/PULL_REQUEST_TEMPLATE.md
vendored
@@ -1,5 +1,8 @@
|
||||
## 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:
|
||||
|
||||
4
.github/settings.yml
vendored
4
.github/settings.yml
vendored
@@ -10,10 +10,10 @@ repository:
|
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description: Next generation distributed, event-driven, parallel config management!
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|
||||
# A URL with more information about the repository
|
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homepage: https://ttboj.wordpress.com/?s=mgmtconfig
|
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homepage: https://purpleidea.com/tags/mgmtconfig/
|
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|
||||
# A comma-separated list of topics to set on the repository
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topics: golang, go, configuration-management, config-management, devops, etcd, distributed-systems, graph-theory
|
||||
topics: golang, go, configuration-management, config-management, devops, etcd, distributed-systems, graph-theory, choreography
|
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# Either `true` to make the repository private, or `false` to make it public.
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private: false
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16
Makefile
16
Makefile
@@ -16,7 +16,7 @@
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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SHELL = /usr/bin/env bash
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.PHONY: all art cleanart version program path deps run race bindata generate build crossbuild clean test gofmt yamlfmt format docs rpmbuild mkdirs rpm srpm spec tar upload upload-sources upload-srpms upload-rpms copr
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.PHONY: all art cleanart version program lang path deps run race bindata generate build crossbuild clean test gofmt yamlfmt format docs rpmbuild mkdirs rpm srpm spec tar upload upload-sources upload-srpms upload-rpms copr
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.SILENT: clean bindata
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GO_FILES := $(shell find . -name '*.go')
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@@ -104,12 +104,16 @@ race:
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# generate go files from non-go source
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bindata:
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@echo "Generating: bindata..."
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$(MAKE) --quiet -C bindata
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generate:
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go generate
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build: bindata $(PROGRAM)
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lang:
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@# recursively run make in child dir named lang
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@echo "Generating: lang..."
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$(MAKE) --quiet -C lang
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$(PROGRAM): $(GO_FILES)
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@echo "Building: $(PROGRAM), version: $(SVERSION)..."
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@@ -128,7 +132,11 @@ $(PROGRAM).static: $(GO_FILES)
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go generate
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go build -a -installsuffix cgo -tags netgo -ldflags '-extldflags "-static" -X main.program=$(PROGRAM) -X main.version=$(SVERSION) -s -w' -o $(PROGRAM).static $(BUILD_FLAGS);
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build: bindata lang $(PROGRAM)
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clean:
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$(MAKE) --quiet -C bindata clean
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$(MAKE) --quiet -C lang clean
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[ ! -e $(PROGRAM) ] || rm $(PROGRAM)
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rm -f *_stringer.go # generated by `go generate`
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rm -f *_mock.go # generated by `go generate`
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@@ -138,8 +146,8 @@ test: bindata
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gofmt:
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# TODO: remove gofmt once goimports has a -s option
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find . -maxdepth 3 -type f -name '*.go' -not -path './old/*' -not -path './tmp/*' -exec gofmt -s -w {} \;
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find . -maxdepth 3 -type f -name '*.go' -not -path './old/*' -not -path './tmp/*' -exec goimports -w {} \;
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find . -maxdepth 6 -type f -name '*.go' -not -path './old/*' -not -path './tmp/*' -not -path './vendor/*' -exec gofmt -s -w {} \;
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find . -maxdepth 6 -type f -name '*.go' -not -path './old/*' -not -path './tmp/*' -not -path './vendor/*' -exec goimports -w {} \;
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yamlfmt:
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||||
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" \;
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15
README.md
15
README.md
@@ -18,10 +18,13 @@ Come join us in the `mgmt` community!
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||||
| Mailing list | [mgmtconfig-list@redhat.com](https://www.redhat.com/mailman/listinfo/mgmtconfig-list) |
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## Status:
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Mgmt is a fairly new project.
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We're working towards being minimally useful for production environments.
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We aren't feature complete for what we'd consider a 1.x release yet.
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With your help you'll be able to influence our design and get us there sooner!
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Mgmt is a next generation automation tool. It has similarities to other tools in
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the configuration management space, but has a fast, modern, distributed systems
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approach. The project contains an engine and a language.
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[Please have a look at an introductory video or blog post.](docs/on-the-web.md)
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Mgmt is a fairly new project. It is usable today, but not yet feature complete.
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With your help you'll be able to influence our design and get us to 1.0 sooner!
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Interested developers should read the [quick start guide](docs/quick-start-guide.md).
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||||
## Documentation:
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||||
@@ -33,6 +36,8 @@ Please read, enjoy and help improve our documentation!
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| [quick start guide](docs/quick-start-guide.md) | for mgmt developers |
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| [frequently asked questions](docs/faq.md) | for everyone |
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| [resource guide](docs/resource-guide.md) | for mgmt developers |
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| [language guide](docs/language-guide.md) | for everyone |
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||||
| [style guide](docs/style-guide.md) | for mgmt developers |
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||||
| [godoc API reference](https://godoc.org/github.com/purpleidea/mgmt) | for mgmt developers |
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| [prometheus guide](docs/prometheus.md) | for everyone |
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||||
| [puppet guide](docs/puppet-guide.md) | for puppet sysadmins |
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||||
@@ -49,7 +54,7 @@ Please get involved by working on one of these items or by suggesting something
|
||||
## 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).
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||||
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.
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Feel free to read my article on [debugging golang programs](https://ttboj.wordpress.com/2016/02/15/debugging-golang-programs/).
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||||
Feel free to read my article on [debugging golang programs](https://purpleidea.com/blog/2016/02/15/debugging-golang-programs/).
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||||
|
||||
## Patches:
|
||||
We'd love to have your patches! Please send them by email, or as a pull request.
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||||
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||||
4
TODO.md
4
TODO.md
@@ -24,7 +24,6 @@ level and how many hours you'd like to spend on the patch.
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- [ ] increment algorithm (linear, exponential, etc...) [:heart:](https://github.com/purpleidea/mgmt/labels/mgmtlove)
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||||
## User/Group resource
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||||
- [ ] base resource [:heart:](https://github.com/purpleidea/mgmt/labels/mgmtlove)
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- [ ] automatic edges to file resource [:heart:](https://github.com/purpleidea/mgmt/labels/mgmtlove)
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||||
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||||
## Virt (libvirt) resource
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||||
@@ -55,8 +54,7 @@ level and how many hours you'd like to spend on the patch.
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||||
- [ ] base plumbing
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||||
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||||
## Language improvements
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||||
- [ ] language design
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||||
- [ ] lexer/parser
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||||
- [ ] more core functions
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||||
- [ ] automatic language formatter, ala `gofmt`
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||||
- [ ] gedit/gnome-builder/gtksourceview syntax highlighting
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||||
- [ ] vim syntax highlighting
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||||
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||||
@@ -20,14 +20,19 @@
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||||
# `bytes, err := bindata.Asset("FILEPATH")`
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||||
# where FILEPATH is the path of the original input file relative to `bindata/`.
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||||
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||||
.PHONY: build
|
||||
.PHONY: build clean
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||||
default: build
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||||
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||||
build: bindata.go
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||||
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||||
# add more input files as dependencies at the end here...
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||||
bindata.go: ../COPYING
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||||
# go-bindata --pkg bindata -o {OUTPUT} {INPUT}
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||||
# go-bindata --pkg bindata -o <OUTPUT> <INPUT>
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||||
go-bindata --pkg bindata -o ./$@ $^
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||||
# gofmt the output file
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||||
gofmt -s -w $@
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||||
@ROOT=$$(dirname "$${BASH_SOURCE}")/.. && $$ROOT/misc/header.sh '$@'
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||||
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||||
clean:
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||||
# remove generated bindata/*.go
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||||
@ROOT=$$(dirname "$${BASH_SOURCE}")/.. && rm *.go
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||||
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||||
@@ -13,13 +13,13 @@ foundation in and for, new and existing software.
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||||
|
||||
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/)
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||||
* [Automatic edges in mgmt](https://ttboj.wordpress.com/2016/03/14/automatic-edges-in-mgmt/)
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||||
* [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/)
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||||
* [Remote execution in mgmt](https://ttboj.wordpress.com/2016/10/07/remote-execution-in-mgmt/)
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||||
* [Send/Recv in mgmt](https://ttboj.wordpress.com/2016/12/07/sendrecv-in-mgmt/)
|
||||
* [Metaparameters in mgmt](https://ttboj.wordpress.com/2017/03/01/metaparameters-in-mgmt/)
|
||||
* [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).
|
||||
@@ -62,7 +62,7 @@ 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/)
|
||||
[https://purpleidea.com/blog/2016/03/14/automatic-edges-in-mgmt/](https://purpleidea.com/blog/2016/03/14/automatic-edges-in-mgmt/)
|
||||
|
||||
### Autogrouping
|
||||
|
||||
@@ -81,7 +81,7 @@ 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/)
|
||||
[https://purpleidea.com/blog/2016/03/30/automatic-grouping-in-mgmt/](https://purpleidea.com/blog/2016/03/30/automatic-grouping-in-mgmt/)
|
||||
|
||||
### Automatic clustering
|
||||
|
||||
@@ -97,7 +97,7 @@ 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/)
|
||||
[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
|
||||
|
||||
@@ -124,7 +124,7 @@ 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/)
|
||||
[https://purpleidea.com/blog/2016/10/07/remote-execution-in-mgmt/](https://purpleidea.com/blog/2016/10/07/remote-execution-in-mgmt/)
|
||||
|
||||
### Puppet support
|
||||
|
||||
@@ -371,7 +371,7 @@ 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/).
|
||||
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).
|
||||
|
||||
@@ -385,4 +385,4 @@ for more information.
|
||||
|
||||
* [github](https://github.com/purpleidea/)
|
||||
* [@purpleidea](https://twitter.com/#!/purpleidea)
|
||||
* [https://ttboj.wordpress.com/](https://ttboj.wordpress.com/)
|
||||
* [https://purpleidea.com/](https://purpleidea.com/)
|
||||
|
||||
@@ -76,12 +76,16 @@ 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 [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/)
|
||||
contact me through my [technical blog](https://purpleidea.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!
|
||||
|
||||
432
docs/language-guide.md
Normal file
432
docs/language-guide.md
Normal file
@@ -0,0 +1,432 @@
|
||||
# Language guide
|
||||
|
||||
## Overview
|
||||
The `mgmt` tool has various frontends, each of which may produce a stream of
|
||||
between zero or more graphs that are passed to the engine for desired state
|
||||
application. In almost all scenarios, you're going to want to use the language
|
||||
frontend. This guide describes some of the internals of the language.
|
||||
|
||||
## Theory
|
||||
The mgmt language is a declarative (immutable) functional, reactive programming
|
||||
language. It is implemented in `golang`. A longer introduction to the language
|
||||
is coming soon!
|
||||
|
||||
### Types
|
||||
All expressions must have a type. A composite type such as a list of strings
|
||||
(`[]str`) is different from a list of integers (`[]int`).
|
||||
|
||||
There _is_ a _variant_ type in the language's type system, but it is only used
|
||||
internally and only appears briefly when needed for type unification hints
|
||||
during static polymorphic function generation. This is an advanced topic which
|
||||
is not required for normal usage of the software.
|
||||
|
||||
The implementation of the internal types can be found in
|
||||
[lang/types/](https://github.com/purpleidea/mgmt/tree/master/lang/types/).
|
||||
|
||||
#### bool
|
||||
A `true` or `false` value.
|
||||
|
||||
#### str
|
||||
Any `"string!"` enclosed in quotes.
|
||||
|
||||
#### int
|
||||
A number like `42` or `-13`. Integers are represented internally as golang's
|
||||
`int64`.
|
||||
|
||||
#### float
|
||||
A floating point number like: `3.1415926`. Float's are represented internally as
|
||||
golang's `float64`.
|
||||
|
||||
#### list
|
||||
An ordered collection of values of the same type, eg: `[6, 7, 8, 9,]`. It is
|
||||
worth mentioning that empty lists have a type, although without type hints it
|
||||
can be impossible to infer the item's type.
|
||||
|
||||
#### map
|
||||
An unordered set of unique keys of the same type and corresponding value pairs
|
||||
of another type, eg: `{"boiling" => 100, "freezing" => 0, "room" => "25", "house" => 22, "canada" => -30,}`.
|
||||
That is to say, all of the keys must have the same type, and all of the values
|
||||
must have the same type. You can use any type for either, although it is
|
||||
probably advisable to avoid using very complex types as map keys.
|
||||
|
||||
#### struct
|
||||
An ordered set of field names and corresponding values, each of their own type,
|
||||
eg: `struct{answer => "42", james => "awesome", is_mgmt_awesome => true,}`.
|
||||
These are useful for combining more than one type into the same value. Note the
|
||||
syntactical difference between these and map's: the key's in map's have types,
|
||||
and as a result, string keys are enclosed in quotes, whereas struct _fields_ are
|
||||
not string values, and as such are bare and specified without quotes.
|
||||
|
||||
#### func
|
||||
An ordered set of optionally named, differently typed input arguments, and a
|
||||
return type, eg: `func(s str) int` or:
|
||||
`func(bool, []str, {str: float}) struct{foo str; bar int}`.
|
||||
|
||||
### Expressions
|
||||
Expressions, and the `Expr` interface need to be better documented. For now
|
||||
please consume
|
||||
[lang/interfaces/ast.go](https://github.com/purpleidea/mgmt/tree/master/lang/interfaces/ast.go).
|
||||
These docs will be expanded on when things are more certain to be stable.
|
||||
|
||||
### Statements
|
||||
Statements, and the `Stmt` interface need to be better documented. For now
|
||||
please consume
|
||||
[lang/interfaces/ast.go](https://github.com/purpleidea/mgmt/tree/master/lang/interfaces/ast.go).
|
||||
These docs will be expanded on when things are more certain to be stable.
|
||||
|
||||
### Stages
|
||||
The mgmt compiler runs in a number of stages. In order of execution they are:
|
||||
* [Lexing](#lexing)
|
||||
* [Parsing](#parsing)
|
||||
* [Interpolation](#interpolation)
|
||||
* [Scope propagation](#scope-propagation)
|
||||
* [Type unification](#type-unification)
|
||||
* [Function graph generation](#function-graph-generation)
|
||||
* [Function engine creation and validation](#function-engine-creation-and-validation)
|
||||
|
||||
All of the above needs to be done every time the source code changes. After this
|
||||
point, the [function engine runs](#function-engine-running-and-interpret) and
|
||||
produces events. On every event, we "[interpret](#function-engine-running-and-interpret)"
|
||||
which produces a resource graph. This series of resource graphs are passed
|
||||
to the engine as they are produced.
|
||||
|
||||
What follows are some notes about each step.
|
||||
|
||||
#### Lexing
|
||||
Lexing is done using [nex](https://github.com/blynn/nex). It is a pure-golang
|
||||
implementation which is similar to _Lex_ or _Flex_, but which produces golang
|
||||
code instead of C. It integrates reasonably well with golang's _yacc_ which is
|
||||
used for parsing. The token definitions are in:
|
||||
[lang/lexer.nex](https://github.com/purpleidea/mgmt/tree/master/lang/lexer.nex).
|
||||
Lexing and parsing run together by calling the `LexParse` method.
|
||||
|
||||
#### Parsing
|
||||
The parser used is golang's implementation of
|
||||
[yacc](https://godoc.org/golang.org/x/tools/cmd/goyacc). The documentation is
|
||||
quite abysmal, so it's helpful to rely on the documentation from standard yacc
|
||||
and trial and error. One small advantage yacc has over standard yacc is that it
|
||||
can produce error messages from examples. The best documentation is to examine
|
||||
the source. There is a short write up available [here](https://research.swtch.com/yyerror).
|
||||
The yacc file exists at:
|
||||
[lang/parser.y](https://github.com/purpleidea/mgmt/tree/master/lang/parser.y).
|
||||
Lexing and parsing run together by calling the `LexParse` method.
|
||||
|
||||
#### Interpolation
|
||||
Interpolation is used to transform the AST (which was produced from lexing and
|
||||
parsing) into one which is either identical or different. It expands strings
|
||||
which might contain expressions to be interpolated (eg: `"the answer is: ${foo}"`)
|
||||
and can be used for other scenarios in which one statement or expression would
|
||||
be better represented by a larger AST. Most nodes in the AST simply return their
|
||||
own node address, and do not modify the AST.
|
||||
|
||||
#### Scope propagation
|
||||
Scope propagation passes the parent scope (starting with the top-level, built-in
|
||||
scope) down through the AST. This is necessary so that children nodes can access
|
||||
variables in the scope if needed. Most AST node's simply pass on the scope
|
||||
without making any changes. The `ExprVar` node naturally consumes scope's and
|
||||
the `StmtProg` node cleverly passes the scope through in the order expected for
|
||||
the out-of-order bind logic to work.
|
||||
|
||||
#### Type unification
|
||||
Each expression must have a known type. The unpleasant option is to force the
|
||||
programmer to specify by annotation every type throughout their whole program
|
||||
so that each `Expr` node in the AST knows what to expect. Type annotation is
|
||||
allowed in situations when you want to explicitly specify a type, or when the
|
||||
compiler cannot deduce it, however, most of it can usually be inferred.
|
||||
|
||||
For type inferrence to work, each node in the AST implements a `Unify` method
|
||||
which is able to return a list of invariants that must hold true. This starts at
|
||||
the top most AST node, and gets called through to it's children to assemble a
|
||||
giant list of invariants. The invariants can take different forms. They can
|
||||
specify that a particular expression must have a particular type, or they can
|
||||
specify that two expressions must have the same types. More complex invariants
|
||||
allow you to specify relationships between different types and expressions.
|
||||
Furthermore, invariants can allow you to specify that only one invariant out of
|
||||
a set must hold true.
|
||||
|
||||
Once the list of invariants has been collected, they are run through an
|
||||
invariant solver. The solver can return either return successfully or with an
|
||||
error. If the solver returns successfully, it means that it has found a trivial
|
||||
mapping between every expression and it's corresponding type. At this point it
|
||||
is a simple task to run `SetType` on every expression so that the types are
|
||||
known. If the solver returns in error, it is usually due to one of two
|
||||
possibilities:
|
||||
|
||||
1. Ambiguity
|
||||
|
||||
The solver does not have enough information to make a definitive or
|
||||
unique determination about the expression to type mappings. The set of
|
||||
invariants is ambiguous, and we cannot continue. An error will be
|
||||
returned to the programmer. In this scenario the user will probably need
|
||||
to add a type annotation, possibly because of a design bug in the user's
|
||||
program.
|
||||
|
||||
2. Conflict
|
||||
|
||||
The solver has conflicting information that cannot be reconciled. In
|
||||
this situation an explicit conflict has been found. If two invariants
|
||||
are found which both expect a particular expression to have different
|
||||
types, then it is not possible to find a valid solution. This almost
|
||||
always happens if the user has made a type error in their program.
|
||||
|
||||
Only one solver currently exists, but it is possible to easily plug in an
|
||||
alternate implementation if someone more skilled in the art of solver design
|
||||
would like to propose a more logical or performant variant.
|
||||
|
||||
#### Function graph generation
|
||||
At this point we have a fully type AST. The AST must now be transformed into a
|
||||
directed, acyclic graph (DAG) data structure that represents the flow of data as
|
||||
necessary for everything to be reactive. Note that this graph is *different*
|
||||
from the resource graph which is produced and sent to the engine. It is just a
|
||||
coincidence that both happen to be DAG's. (You don't freak out when you see a
|
||||
list data structure show up in more than one place, do you?)
|
||||
|
||||
To produce this graph, each node has a `Graph` method which it can call. This
|
||||
starts at the top most node, and is called down through the AST. The edges in
|
||||
the graphs must represent the individual expression values which are passed
|
||||
from node to node. The names of the edges must match the function type argument
|
||||
names which are used in the definition of the corresponding function. These
|
||||
corresponding functions must exist for each expression node and are produced by
|
||||
calling that expression's `Func` method. These are usually called by the
|
||||
function engine during function creation and validation.
|
||||
|
||||
#### Function engine creation and validation
|
||||
Finally we have a graph of the data flows. The function engine must first
|
||||
initialize which creates references to each of the necessary function
|
||||
implementations, and gets information about each one. It then needs to be type
|
||||
checked to ensure that the data flows all correctly match what is expected. If
|
||||
you were to pass an `int` to a function expecting a `bool`, this would be a
|
||||
problem. If all goes well, the program should get run shortly.
|
||||
|
||||
#### Function engine running and interpret
|
||||
At this point the function engine runs. It produces a stream of events which
|
||||
cause the `Output()` method of the top-level program to run, which produces the
|
||||
list of resources and edges. These are then transformed into the resource graph
|
||||
which is passed to the engine.
|
||||
|
||||
### Function API
|
||||
If you'd like to create a built-in, core function, you'll need to implement the
|
||||
function API interface named `Func`. It can be found in
|
||||
[lang/interfaces/func.go](https://github.com/purpleidea/mgmt/tree/master/lang/interfaces/func.go).
|
||||
Your function must have a specific type. For example, a simple math function
|
||||
might have a signature of `func(x int, x int) int`. As you can see, all the
|
||||
types are known _before_ compile time.
|
||||
|
||||
What follows are each of the method signatures and a description of each.
|
||||
Failure to implement the API correctly can cause the function graph engine to
|
||||
block, or the program to panic.
|
||||
|
||||
### Info
|
||||
```golang
|
||||
Info() *Info
|
||||
```
|
||||
|
||||
The Info method must return a struct containing some information about your
|
||||
function. The struct has the following type:
|
||||
|
||||
```golang
|
||||
type Info struct {
|
||||
Sig *types.Type // the signature of the function, must be KindFunc
|
||||
}
|
||||
```
|
||||
|
||||
You must implement this correctly. Other fields in the `Info` struct may be
|
||||
added in the future. This method is usually called before any other, and should
|
||||
not depend on any other method being called first. Other methods must not depend
|
||||
on this method being called first.
|
||||
|
||||
#### Example
|
||||
```golang
|
||||
func (obj *FooFunc) Info() *interfaces.Info {
|
||||
return &interfaces.Info{
|
||||
Sig: types.NewType("func(a str, b int) float"),
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
### Init
|
||||
```golang
|
||||
Init(*Init) error
|
||||
```
|
||||
|
||||
Init is called by the function graph engine to create an implementation of this
|
||||
function. It is passed in a struct of the following form:
|
||||
|
||||
```golang
|
||||
type Init struct {
|
||||
Hostname string // uuid for the host
|
||||
Input chan types.Value // Engine will close `input` chan
|
||||
Output chan types.Value // Stream must close `output` chan
|
||||
World resources.World
|
||||
Debug bool
|
||||
Logf func(format string, v ...interface{})
|
||||
}
|
||||
```
|
||||
|
||||
These values and references may be used (wisely) inside your function. `Input`
|
||||
will contain a channel of input structs matching the expected input signature
|
||||
for your function. `Output` will be the channel which you must send values to
|
||||
whenever a new value should be produced. This must be done in the `Stream()`
|
||||
function. You may carefully use `World` to access functionality provided by the
|
||||
engine. You may use `Logf` to log informational messages, however there is no
|
||||
guarantee that they will be displayed to the user. `Debug` specifies whether the
|
||||
function is running in a user-requested debug mode. This might cause you to want
|
||||
to print more log messages for example. You will need to save references to any
|
||||
or all of these info fields that you wish to use in the struct implementing this
|
||||
`Func` interface. At a minimum you will need to save `Output` as a minimum of
|
||||
one value must be produced.
|
||||
|
||||
#### Example
|
||||
```golang
|
||||
Please see the example functions in
|
||||
[lang/funcs/public/](https://github.com/purpleidea/mgmt/tree/master/lang/funcs/public/).
|
||||
```
|
||||
|
||||
### Stream
|
||||
```golang
|
||||
Stream() error
|
||||
```
|
||||
|
||||
Stream is called by the function engine when it is ready for your function to
|
||||
start accepting input and producing output. You must always produce at least one
|
||||
value. Failure to produce at least one value will probably cause the function
|
||||
engine to hang waiting for your output. This function must close the `Output`
|
||||
channel when it has no more values to send. The engine will close the `Input`
|
||||
channel when it has no more values to send. This may or may not influence
|
||||
whether or not you close the `Output` channel.
|
||||
|
||||
#### Example
|
||||
```golang
|
||||
Please see the example functions in
|
||||
[lang/funcs/public/](https://github.com/purpleidea/mgmt/tree/master/lang/funcs/public/).
|
||||
```
|
||||
|
||||
### Close
|
||||
```golang
|
||||
Close() error
|
||||
```
|
||||
|
||||
Close asks the particular function to shutdown its `Stream()` function and
|
||||
return.
|
||||
|
||||
#### Example
|
||||
```golang
|
||||
Please see the example functions in
|
||||
[lang/funcs/public/](https://github.com/purpleidea/mgmt/tree/master/lang/funcs/public/).
|
||||
```
|
||||
|
||||
### Polymorphic Function API
|
||||
For some functions, it might be helpful to be able to implement a function once,
|
||||
but to have multiple polymorphic variants that can be chosen at compile time.
|
||||
For this more advanced topic, you will need to use the
|
||||
[Polymorphic Function API](#polymorphic-function-api). This will help with code
|
||||
reuse when you have a small, finite number of possible type signatures, and also
|
||||
for more complicated cases where you might have an infinite number of possible
|
||||
type signatures. (eg: `[]str`, or `[][]str`, or `[][][]str`, etc...)
|
||||
|
||||
Suppose you want to implement a function which can assume different type
|
||||
signatures. The mgmt language does not support polymorphic types-- you must use
|
||||
static types throughout the language, however, it is legal to implement a
|
||||
function which can take different specific type signatures based on how it is
|
||||
used. For example, you might wish to add a math function which could take the
|
||||
form of `func(x int, x int) int` or `func(x float, x float) float` depending on
|
||||
the input values. You might also want to implement a function which takes an
|
||||
arbitrary number of input arguments (the number must be statically fixed at the
|
||||
compile time of your program though) and which returns a string.
|
||||
|
||||
The `PolyFunc` interface adds additional methods which you must implement to
|
||||
satisfy such a function implementation. If you'd like to implement such a
|
||||
function, then please notify the project authors, and they will expand this
|
||||
section with a longer description of the process.
|
||||
|
||||
#### Examples
|
||||
|
||||
What follows are a few examples that might help you understand some of the
|
||||
language details.
|
||||
|
||||
##### Example Foo
|
||||
TODO: please add an example here!
|
||||
|
||||
##### Example Bar
|
||||
TODO: please add an example here!
|
||||
|
||||
## 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.)
|
||||
|
||||
### What is the difference between `ExprIf` and `StmtIf`?
|
||||
|
||||
The language contains both an `if` expression, and and `if` statement. An `if`
|
||||
expression takes a boolean conditional *and* it must contain exactly _two_
|
||||
branches (a `then` and an `else` branch) which each contain one expression. The
|
||||
`if` expression _will_ return the value of one of the two branches based on the
|
||||
conditional.
|
||||
|
||||
#### Example:
|
||||
```
|
||||
# this is an if expression, and both branches must exist
|
||||
$b = true
|
||||
$x = if $b {
|
||||
42
|
||||
} else {
|
||||
-13
|
||||
}
|
||||
```
|
||||
|
||||
The `if` statement also takes a boolean conditional, but it may have either one
|
||||
or two branches. Branches must only directly contain statements. The `if`
|
||||
statement does not return any value, but it does produce output when it is
|
||||
evaluated. The output consists primarily of resources (vertices) and edges.
|
||||
|
||||
#### Example:
|
||||
```
|
||||
# this is an if statement, and in this scenario the else branch was omitted
|
||||
$b = true
|
||||
if $b {
|
||||
file "/tmp/hello" {
|
||||
content => "world",
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
### I don't like the mgmt language, is there an alternative?
|
||||
|
||||
Yes, the language is just one of the available "frontends" that passes a stream
|
||||
of graphs to the engine "backend". While it _is_ the recommended way of using
|
||||
mgmt, you're welcome to either use an alternate frontend, or write your own. To
|
||||
write your own frontend, you must implement the
|
||||
[GAPI](https://github.com/purpleidea/mgmt/blob/master/gapi/gapi.go) interface.
|
||||
|
||||
### I'm an expert in FRP, and you got it all wrong; even the names of things!
|
||||
|
||||
I am certainly no expert in FRP, and I've certainly got lots more to learn. One
|
||||
thing FRP experts might notice is that some of the concepts from FRP are either
|
||||
named differently, or are notably absent.
|
||||
|
||||
In mgmt, we don't talk about behaviours, events, or signals in the strict FRP
|
||||
definitons of the words. Firstly, because we only support discretized, streams
|
||||
of values with no plan to add continuous semantics. Secondly, because we prefer
|
||||
to use terms which are more natural and relatable to what our target audience is
|
||||
expecting. Our users are more likely to have a background in Physiology, or
|
||||
systems administration than a background in FRP.
|
||||
|
||||
Having said that, we hope that the FRP community will engage with us and help
|
||||
improve the parts that we got wrong. Even if that means adding continuous
|
||||
behaviours!
|
||||
|
||||
### This is brilliant, may I give you a high-five?
|
||||
|
||||
Thank you, and yes, probably. "Props" may also be accepted, although patches are
|
||||
preferred. If you can't do either, [donations](https://purpleidea.com/misc/donate/)
|
||||
to support the project are welcome too!
|
||||
|
||||
### 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 changes or other improvements to the language, please
|
||||
let us know! We're still pre 1.0 and pre 0.1 and happy to change it in order to
|
||||
get it right!
|
||||
@@ -6,30 +6,30 @@ if we missed something that you think is relevant!
|
||||
## Links
|
||||
| Author | Format | Subject |
|
||||
|---|---|---|
|
||||
| James Shubin | blog | [Next generation configuration mgmt](https://ttboj.wordpress.com/2016/01/18/next-generation-configuration-mgmt/) |
|
||||
| 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://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/) |
|
||||
| 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://ttboj.wordpress.com/2016/06/20/automatic-clustering-in-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) ([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 | 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://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/) |
|
||||
| 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://roidelapluie.be/blog/2017/02/14/mgmt-augeas/) |
|
||||
| James Shubin | blog | [Metaparameters in mgmt](https://ttboj.wordpress.com/2017/03/01/metaparameters-in-mgmt/) |
|
||||
| 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) |
|
||||
|
||||
@@ -4,7 +4,7 @@
|
||||
This guide is intended for developers. Once `mgmt` is minimally viable, we'll
|
||||
publish a quick start guide for users too. If you're brand new to `mgmt`, it's
|
||||
probably a good idea to start by reading the
|
||||
[introductory article](https://ttboj.wordpress.com/2016/01/18/next-generation-configuration-mgmt/)
|
||||
[introductory article](https://purpleidea.com/blog/2016/01/18/next-generation-configuration-mgmt/)
|
||||
or to watch an [introductory video](https://www.youtube.com/watch?v=LkEtBVLfygE&html5=1).
|
||||
Once you're familiar with the general idea, please start hacking...
|
||||
|
||||
@@ -38,14 +38,12 @@ cd $GOPATH/src/github.com/purpleidea/mgmt
|
||||
* Run `make build` to get a freshly built `mgmt` binary.
|
||||
|
||||
### Running mgmt
|
||||
* 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.
|
||||
* Run `time ./mgmt run --lang examples/lang/hello0.mcl --tmp-prefix` to try out a very simple example!
|
||||
* Look in that example file that you ran to see if you can figure out what it did!
|
||||
* The yaml frontend is provided as a developer tool to test the engine until the language is ready.
|
||||
* Have fun hacking on our future technology and get involved to shape the project!
|
||||
|
||||
## Examples
|
||||
Please look in the [examples/](../examples/) folder for some more examples!
|
||||
Please look in the [examples/lang/](../examples/lang/) folder for some more examples!
|
||||
|
||||
## Vagrant
|
||||
If you would like to avoid doing the above steps manually, we have prepared a
|
||||
|
||||
@@ -16,7 +16,7 @@ Resources in `mgmt` are similar to resources in other systems in that they 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://ttboj.wordpress.com/2016/01/18/next-generation-configuration-mgmt/)
|
||||
[original article](https://purpleidea.com/blog/2016/01/18/next-generation-configuration-mgmt/)
|
||||
on the subject.
|
||||
|
||||
## Resource API
|
||||
@@ -465,14 +465,14 @@ func init() { // special golang method that runs once
|
||||
```
|
||||
|
||||
## Automatic edges
|
||||
Automatic edges in `mgmt` are well described in [this article](https://ttboj.wordpress.com/2016/03/14/automatic-edges-in-mgmt/).
|
||||
Automatic edges in `mgmt` are well described in [this article](https://purpleidea.com/blog/2016/03/14/automatic-edges-in-mgmt/).
|
||||
The best example of this technique can be seen in the `svc` resource.
|
||||
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!
|
||||
|
||||
## Automatic grouping
|
||||
Automatic grouping in `mgmt` is well described in [this article](https://ttboj.wordpress.com/2016/03/30/automatic-grouping-in-mgmt/).
|
||||
Automatic grouping in `mgmt` is well described in [this article](https://purpleidea.com/blog/2016/03/30/automatic-grouping-in-mgmt/).
|
||||
The best example of this technique can be seen in the `pkg` resource.
|
||||
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
|
||||
@@ -481,7 +481,7 @@ work on a resource that uses this feature, or to add it to an existing one!
|
||||
|
||||
## Send/Recv
|
||||
In `mgmt` there is a novel concept called _Send/Recv_. For some background,
|
||||
please [read the introductory article](https://ttboj.wordpress.com/2016/12/07/sendrecv-in-mgmt/).
|
||||
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 any resource specific code.
|
||||
Any time that one of the destination values is changed, the engine automatically
|
||||
@@ -547,7 +547,7 @@ 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!
|
||||
|
||||
### Where can I find more information about mgmt?
|
||||
Additional blog posts, videos and other material [is available!](https://github.com/purpleidea/mgmt/#on-the-web).
|
||||
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,
|
||||
|
||||
95
docs/style-guide.md
Normal file
95
docs/style-guide.md
Normal file
@@ -0,0 +1,95 @@
|
||||
# Style guide
|
||||
|
||||
## Overview
|
||||
|
||||
This document aims to be a reference for the desired style for patches to mgmt.
|
||||
In particular it describes conventions which we use which are not officially
|
||||
enforced by the `gofmt` tool, and which might not be clearly defined elsewhere.
|
||||
Most of these are 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.
|
||||
|
||||
## 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
|
||||
}
|
||||
```
|
||||
|
||||
## 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`.
|
||||
|
||||
## Suggestions
|
||||
If you have any ideas for suggestions or other improvements to this guide,
|
||||
please let us know!
|
||||
94
etcd/client.go
Normal file
94
etcd/client.go
Normal file
@@ -0,0 +1,94 @@
|
||||
// Mgmt
|
||||
// Copyright (C) 2013-2018+ 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 <http://www.gnu.org/licenses/>.
|
||||
|
||||
package etcd
|
||||
|
||||
import (
|
||||
"time"
|
||||
|
||||
etcd "github.com/coreos/etcd/clientv3" // "clientv3"
|
||||
errwrap "github.com/pkg/errors"
|
||||
context "golang.org/x/net/context"
|
||||
)
|
||||
|
||||
// ClientEtcd provides a simple etcd client for deploy and status operations.
|
||||
type ClientEtcd struct {
|
||||
Seeds []string // list of endpoints to try to connect
|
||||
|
||||
client *etcd.Client
|
||||
}
|
||||
|
||||
// GetClient returns a handle to the raw etcd client object.
|
||||
func (obj *ClientEtcd) GetClient() *etcd.Client {
|
||||
return obj.client
|
||||
}
|
||||
|
||||
// GetConfig returns the config struct to be used for the etcd client connect.
|
||||
func (obj *ClientEtcd) GetConfig() etcd.Config {
|
||||
cfg := etcd.Config{
|
||||
Endpoints: obj.Seeds,
|
||||
// RetryDialer chooses the next endpoint to use
|
||||
// it comes with a default dialer if unspecified
|
||||
DialTimeout: 5 * time.Second,
|
||||
}
|
||||
return cfg
|
||||
}
|
||||
|
||||
// Connect connects the client to a server, and then builds the *API structs.
|
||||
// If reconnect is true, it will force a reconnect with new config endpoints.
|
||||
func (obj *ClientEtcd) Connect() error {
|
||||
if obj.client != nil { // memoize
|
||||
return nil
|
||||
}
|
||||
|
||||
var err error
|
||||
cfg := obj.GetConfig()
|
||||
obj.client, err = etcd.New(cfg) // connect!
|
||||
if err != nil {
|
||||
return errwrap.Wrapf(err, "client connect error")
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// Destroy cleans up the entire etcd client connection.
|
||||
func (obj *ClientEtcd) Destroy() error {
|
||||
err := obj.client.Close()
|
||||
//obj.wg.Wait()
|
||||
return err
|
||||
}
|
||||
|
||||
// Get runs a get on the client connection. This has the same signature as our
|
||||
// EmbdEtcd Get function.
|
||||
func (obj *ClientEtcd) Get(path string, opts ...etcd.OpOption) (map[string]string, error) {
|
||||
resp, err := obj.client.Get(context.TODO(), path, opts...)
|
||||
if err != nil || resp == nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
// TODO: write a resp.ToMap() function on https://godoc.org/github.com/coreos/etcd/etcdserver/etcdserverpb#RangeResponse
|
||||
result := make(map[string]string)
|
||||
for _, x := range resp.Kvs {
|
||||
result[string(x.Key)] = string(x.Value)
|
||||
}
|
||||
return result, nil
|
||||
}
|
||||
|
||||
// Txn runs a transaction on the client connection. This has the same signature
|
||||
// as our EmbdEtcd Txn function.
|
||||
func (obj *ClientEtcd) Txn(ifcmps []etcd.Cmp, thenops, elseops []etcd.Op) (*etcd.TxnResponse, error) {
|
||||
return obj.client.KV.Txn(context.TODO()).If(ifcmps...).Then(thenops...).Else(elseops...).Commit()
|
||||
}
|
||||
171
etcd/deploy.go
Normal file
171
etcd/deploy.go
Normal file
@@ -0,0 +1,171 @@
|
||||
// Mgmt
|
||||
// Copyright (C) 2013-2018+ 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 <http://www.gnu.org/licenses/>.
|
||||
|
||||
package etcd
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"strconv"
|
||||
"strings"
|
||||
|
||||
etcd "github.com/coreos/etcd/clientv3"
|
||||
errwrap "github.com/pkg/errors"
|
||||
)
|
||||
|
||||
const (
|
||||
deployPath = "deploy"
|
||||
payloadPath = "payload"
|
||||
hashPath = "hash"
|
||||
)
|
||||
|
||||
// WatchDeploy returns a channel which spits out events on new deploy activity.
|
||||
// FIXME: It should close the channel when it's done, and spit out errors when
|
||||
// something goes wrong.
|
||||
func WatchDeploy(obj *EmbdEtcd) chan error {
|
||||
// key structure is $NS/deploy/$id/payload = $data
|
||||
path := fmt.Sprintf("%s/%s/", NS, deployPath)
|
||||
ch := make(chan error, 1)
|
||||
// FIXME: fix our API so that we get a close event on shutdown.
|
||||
callback := func(re *RE) error {
|
||||
// TODO: is this even needed? it used to happen on conn errors
|
||||
//log.Printf("Etcd: Watch: Path: %v", path) // event
|
||||
if re == nil || re.response.Canceled {
|
||||
return fmt.Errorf("watch is empty") // will cause a CtxError+retry
|
||||
}
|
||||
if len(ch) == 0 { // send event only if one isn't pending
|
||||
ch <- nil // event
|
||||
}
|
||||
return nil
|
||||
}
|
||||
_, _ = obj.AddWatcher(path, callback, true, false, etcd.WithPrefix()) // no need to check errors
|
||||
return ch
|
||||
}
|
||||
|
||||
// GetDeploys gets all the available deploys.
|
||||
func GetDeploys(obj Client) (map[uint64]string, error) {
|
||||
// key structure is $NS/deploy/$id/payload = $data
|
||||
path := fmt.Sprintf("%s/%s/", NS, deployPath)
|
||||
keyMap, err := obj.Get(path, etcd.WithPrefix(), etcd.WithSort(etcd.SortByKey, etcd.SortAscend))
|
||||
if err != nil {
|
||||
return nil, errwrap.Wrapf(err, "could not get deploy")
|
||||
}
|
||||
result := make(map[uint64]string)
|
||||
for key, val := range keyMap {
|
||||
if !strings.HasPrefix(key, path) { // sanity check
|
||||
continue
|
||||
}
|
||||
|
||||
str := strings.Split(key[len(path):], "/")
|
||||
if len(str) != 2 {
|
||||
return nil, fmt.Errorf("unexpected chunk count of %d", len(str))
|
||||
}
|
||||
if s := str[1]; s != payloadPath {
|
||||
continue // skip, maybe there are other future additions
|
||||
}
|
||||
|
||||
var id uint64
|
||||
var err error
|
||||
x := str[0]
|
||||
if id, err = strconv.ParseUint(x, 10, 64); err != nil {
|
||||
return nil, fmt.Errorf("invalid id of `%s`", x)
|
||||
}
|
||||
|
||||
// TODO: do some sort of filtering here?
|
||||
//log.Printf("Etcd: GetDeploys(%s): Id => Data: %d => %s", key, id, val)
|
||||
result[id] = val
|
||||
}
|
||||
return result, nil
|
||||
}
|
||||
|
||||
// GetDeploy gets the latest deploy if id == 0, otherwise it returns the deploy
|
||||
// with the specified id if it exists.
|
||||
// FIXME: implement this more efficiently so that it doesn't have to download *all* the old deploys from etcd!
|
||||
func GetDeploy(obj Client, id uint64) (string, error) {
|
||||
result, err := GetDeploys(obj)
|
||||
if err != nil {
|
||||
return "", err
|
||||
}
|
||||
if id != 0 {
|
||||
str, exists := result[id]
|
||||
if !exists {
|
||||
return "", fmt.Errorf("can't find id `%d`", id)
|
||||
}
|
||||
return str, nil
|
||||
}
|
||||
// find the latest id
|
||||
var max uint64
|
||||
for i := range result {
|
||||
if i > max {
|
||||
max = i
|
||||
}
|
||||
}
|
||||
if max == 0 {
|
||||
return "", nil // no results yet
|
||||
}
|
||||
return result[max], nil
|
||||
}
|
||||
|
||||
// AddDeploy adds a new deploy. It takes an id and ensures it's sequential. If
|
||||
// hash is not empty, then it will check that the pHash matches what the
|
||||
// previous hash was, and also adds this new hash along side the id. This is
|
||||
// useful to make sure you get a linear chain of git patches, and to avoid two
|
||||
// contributors pushing conflicting deploys. This isn't git specific, and so any
|
||||
// arbitrary string hash can be used.
|
||||
// FIXME: prune old deploys from the store when they aren't needed anymore...
|
||||
func AddDeploy(obj Client, id uint64, hash, pHash string, data *string) error {
|
||||
// key structure is $NS/deploy/$id/payload = $data
|
||||
// key structure is $NS/deploy/$id/hash = $hash
|
||||
path := fmt.Sprintf("%s/%s/%d/%s", NS, deployPath, id, payloadPath)
|
||||
tPath := fmt.Sprintf("%s/%s/%d/%s", NS, deployPath, id, hashPath)
|
||||
ifs := []etcd.Cmp{} // list matching the desired state
|
||||
ops := []etcd.Op{} // list of ops in this transaction (then)
|
||||
|
||||
// TODO: use https://github.com/coreos/etcd/pull/7417 if merged
|
||||
// we're append only, so ensure this unique deploy id doesn't exist
|
||||
ifs = append(ifs, etcd.Compare(etcd.Version(path), "=", 0)) // KeyMissing
|
||||
//ifs = append(ifs, etcd.KeyMissing(path))
|
||||
|
||||
// don't look for previous deploy if this is the first deploy ever
|
||||
if id > 1 {
|
||||
// we append sequentially, so ensure previous key *does* exist
|
||||
prev := fmt.Sprintf("%s/%s/%d/%s", NS, deployPath, id-1, payloadPath)
|
||||
ifs = append(ifs, etcd.Compare(etcd.Version(prev), ">", 0)) // KeyExists
|
||||
//ifs = append(ifs, etcd.KeyExists(prev))
|
||||
|
||||
if hash != "" && pHash != "" {
|
||||
// does the previously stored hash match what we expect?
|
||||
prevHash := fmt.Sprintf("%s/%s/%d/%s", NS, deployPath, id-1, hashPath)
|
||||
ifs = append(ifs, etcd.Compare(etcd.Value(prevHash), "=", pHash))
|
||||
}
|
||||
}
|
||||
|
||||
ops = append(ops, etcd.OpPut(path, *data))
|
||||
if hash != "" {
|
||||
ops = append(ops, etcd.OpPut(tPath, hash)) // store new hash as well
|
||||
}
|
||||
|
||||
// it's important to do this in one transaction, and atomically, because
|
||||
// this way, we only generate one watch event, and only when it's needed
|
||||
result, err := obj.Txn(ifs, ops, nil)
|
||||
if err != nil {
|
||||
return errwrap.Wrapf(err, "error creating deploy id %d: %s", id)
|
||||
}
|
||||
if !result.Succeeded {
|
||||
return fmt.Errorf("could not create deploy id %d", id)
|
||||
}
|
||||
return nil // success
|
||||
}
|
||||
86
etcd/etcd.go
86
etcd/etcd.go
@@ -79,14 +79,14 @@ import (
|
||||
|
||||
// constant parameters which may need to be tweaked or customized
|
||||
const (
|
||||
NS = "_mgmt" // root namespace for mgmt operations
|
||||
seedSentinel = "_seed" // you must not name your hostname this
|
||||
MaxStartServerTimeout = 60 // max number of seconds to wait for server to start
|
||||
MaxStartServerRetries = 3 // number of times to retry starting the etcd server
|
||||
maxClientConnectRetries = 5 // number of times to retry consecutive connect failures
|
||||
selfRemoveTimeout = 3 // give unnominated members a chance to self exit
|
||||
exitDelay = 3 // number of sec of inactivity after exit to clean up
|
||||
DefaultIdealClusterSize = 5 // default ideal cluster size target for initial seed
|
||||
NS = "/_mgmt" // root namespace for mgmt operations
|
||||
seedSentinel = "_seed" // you must not name your hostname this
|
||||
MaxStartServerTimeout = 60 // max number of seconds to wait for server to start
|
||||
MaxStartServerRetries = 3 // number of times to retry starting the etcd server
|
||||
maxClientConnectRetries = 5 // number of times to retry consecutive connect failures
|
||||
selfRemoveTimeout = 3 // give unnominated members a chance to self exit
|
||||
exitDelay = 3 // number of sec of inactivity after exit to clean up
|
||||
DefaultIdealClusterSize = 5 // default ideal cluster size target for initial seed
|
||||
DefaultClientURL = "127.0.0.1:2379"
|
||||
DefaultServerURL = "127.0.0.1:2380"
|
||||
)
|
||||
@@ -170,11 +170,12 @@ type EmbdEtcd struct { // EMBeddeD etcd
|
||||
ctxErr error // permanent ctx error
|
||||
|
||||
// exit and cleanup related
|
||||
cancelLock sync.Mutex // lock for the cancels list
|
||||
cancels []func() // array of every cancel function for watches
|
||||
exiting bool
|
||||
exitchan chan struct{}
|
||||
exitTimeout <-chan time.Time
|
||||
cancelLock sync.Mutex // lock for the cancels list
|
||||
cancels []func() // array of every cancel function for watches
|
||||
exiting bool
|
||||
exitchan chan struct{}
|
||||
exitchanCb chan struct{}
|
||||
exitwg *sync.WaitGroup // wait for main loops to shutdown
|
||||
|
||||
hostname string
|
||||
memberID uint64 // cluster membership id of server if running
|
||||
@@ -220,14 +221,15 @@ func NewEmbdEtcd(hostname string, seeds, clientURLs, serverURLs, advertiseClient
|
||||
idealClusterSize = 0 // unset, get from running cluster
|
||||
}
|
||||
obj := &EmbdEtcd{
|
||||
exitchan: make(chan struct{}), // exit signal for main loop
|
||||
exitTimeout: nil,
|
||||
awq: make(chan *AW),
|
||||
wevents: make(chan *RE),
|
||||
setq: make(chan *KV),
|
||||
getq: make(chan *GQ),
|
||||
delq: make(chan *DL),
|
||||
txnq: make(chan *TN),
|
||||
exitchan: make(chan struct{}), // exit signal for main loop
|
||||
exitchanCb: make(chan struct{}),
|
||||
exitwg: &sync.WaitGroup{},
|
||||
awq: make(chan *AW),
|
||||
wevents: make(chan *RE),
|
||||
setq: make(chan *KV),
|
||||
getq: make(chan *GQ),
|
||||
delq: make(chan *DL),
|
||||
txnq: make(chan *TN),
|
||||
|
||||
nominated: make(etcdtypes.URLsMap),
|
||||
|
||||
@@ -265,6 +267,11 @@ func NewEmbdEtcd(hostname string, seeds, clientURLs, serverURLs, advertiseClient
|
||||
return obj
|
||||
}
|
||||
|
||||
// GetClient returns a handle to the raw etcd client object for those scenarios.
|
||||
func (obj *EmbdEtcd) GetClient() *etcd.Client {
|
||||
return obj.client
|
||||
}
|
||||
|
||||
// GetConfig returns the config struct to be used for the etcd client connect.
|
||||
func (obj *EmbdEtcd) GetConfig() etcd.Config {
|
||||
endpoints := []string{}
|
||||
@@ -363,11 +370,11 @@ func (obj *EmbdEtcd) Startup() error {
|
||||
go obj.Loop() // start main loop
|
||||
|
||||
// TODO: implement native etcd watcher method on member API changes
|
||||
path := fmt.Sprintf("/%s/nominated/", NS)
|
||||
path := fmt.Sprintf("%s/nominated/", NS)
|
||||
go obj.AddWatcher(path, obj.nominateCallback, true, false, etcd.WithPrefix()) // no block
|
||||
|
||||
// setup ideal cluster size watcher
|
||||
key := fmt.Sprintf("/%s/idealClusterSize", NS)
|
||||
key := fmt.Sprintf("%s/idealClusterSize", NS)
|
||||
go obj.AddWatcher(key, obj.idealClusterSizeCallback, true, false) // no block
|
||||
|
||||
// if we have no endpoints, it means we are bootstrapping...
|
||||
@@ -393,7 +400,7 @@ func (obj *EmbdEtcd) Startup() error {
|
||||
}
|
||||
|
||||
if !obj.noServer {
|
||||
path := fmt.Sprintf("/%s/volunteers/", NS)
|
||||
path := fmt.Sprintf("%s/volunteers/", NS)
|
||||
go obj.AddWatcher(path, obj.volunteerCallback, true, false, etcd.WithPrefix()) // no block
|
||||
}
|
||||
|
||||
@@ -431,7 +438,7 @@ func (obj *EmbdEtcd) Startup() error {
|
||||
}
|
||||
}
|
||||
|
||||
go obj.AddWatcher(fmt.Sprintf("/%s/endpoints/", NS), obj.endpointCallback, true, false, etcd.WithPrefix())
|
||||
go obj.AddWatcher(fmt.Sprintf("%s/endpoints/", NS), obj.endpointCallback, true, false, etcd.WithPrefix())
|
||||
|
||||
if err := obj.Connect(false); err != nil { // don't exit from this Startup function until connected!
|
||||
return err
|
||||
@@ -461,7 +468,8 @@ func (obj *EmbdEtcd) Destroy() error {
|
||||
}
|
||||
obj.cancelLock.Unlock()
|
||||
|
||||
obj.exitchan <- struct{}{} // cause main loop to exit
|
||||
close(obj.exitchan) // cause main loop to exit
|
||||
close(obj.exitchanCb)
|
||||
|
||||
obj.rLock.Lock()
|
||||
if obj.client != nil {
|
||||
@@ -474,6 +482,7 @@ func (obj *EmbdEtcd) Destroy() error {
|
||||
//if obj.server != nil {
|
||||
// return obj.DestroyServer()
|
||||
//}
|
||||
obj.exitwg.Wait()
|
||||
return nil
|
||||
}
|
||||
|
||||
@@ -715,12 +724,15 @@ func (obj *EmbdEtcd) CtxError(ctx context.Context, err error) (context.Context,
|
||||
|
||||
// CbLoop is the loop where callback execution is serialized.
|
||||
func (obj *EmbdEtcd) CbLoop() {
|
||||
obj.exitwg.Add(1)
|
||||
defer obj.exitwg.Done()
|
||||
cuid := obj.converger.Register()
|
||||
cuid.SetName("Etcd: CbLoop")
|
||||
defer cuid.Unregister()
|
||||
if e := obj.Connect(false); e != nil {
|
||||
return // fatal
|
||||
}
|
||||
var exitTimeout <-chan time.Time // = nil is implied
|
||||
// we use this timer because when we ignore un-converge events and loop,
|
||||
// we reset the ConvergedTimer case statement, ruining the timeout math!
|
||||
cuid.StartTimer()
|
||||
@@ -760,8 +772,18 @@ func (obj *EmbdEtcd) CbLoop() {
|
||||
log.Printf("Trace: Etcd: CbLoop: Event: FinishLoop")
|
||||
}
|
||||
|
||||
// exit loop signal
|
||||
case <-obj.exitchanCb:
|
||||
obj.exitchanCb = nil
|
||||
log.Println("Etcd: Exiting loop shortly...")
|
||||
// activate exitTimeout switch which only opens after N
|
||||
// seconds of inactivity in this select switch, which
|
||||
// lets everything get bled dry to avoid blocking calls
|
||||
// which would otherwise block us from exiting cleanly!
|
||||
exitTimeout = util.TimeAfterOrBlock(exitDelay)
|
||||
|
||||
// exit loop commit
|
||||
case <-obj.exitTimeout:
|
||||
case <-exitTimeout:
|
||||
log.Println("Etcd: Exiting callback loop!")
|
||||
cuid.StopTimer() // clean up nicely
|
||||
return
|
||||
@@ -771,12 +793,15 @@ func (obj *EmbdEtcd) CbLoop() {
|
||||
|
||||
// Loop is the main loop where everything is serialized.
|
||||
func (obj *EmbdEtcd) Loop() {
|
||||
obj.exitwg.Add(1) // TODO: add these to other go routines?
|
||||
defer obj.exitwg.Done()
|
||||
cuid := obj.converger.Register()
|
||||
cuid.SetName("Etcd: Loop")
|
||||
defer cuid.Unregister()
|
||||
if e := obj.Connect(false); e != nil {
|
||||
return // fatal
|
||||
}
|
||||
var exitTimeout <-chan time.Time // = nil is implied
|
||||
cuid.StartTimer()
|
||||
for {
|
||||
ctx := context.Background() // TODO: inherit as input argument?
|
||||
@@ -911,15 +936,16 @@ func (obj *EmbdEtcd) Loop() {
|
||||
|
||||
// exit loop signal
|
||||
case <-obj.exitchan:
|
||||
obj.exitchan = nil
|
||||
log.Println("Etcd: Exiting loop shortly...")
|
||||
// activate exitTimeout switch which only opens after N
|
||||
// seconds of inactivity in this select switch, which
|
||||
// lets everything get bled dry to avoid blocking calls
|
||||
// which would otherwise block us from exiting cleanly!
|
||||
obj.exitTimeout = util.TimeAfterOrBlock(exitDelay)
|
||||
exitTimeout = util.TimeAfterOrBlock(exitDelay)
|
||||
|
||||
// exit loop commit
|
||||
case <-obj.exitTimeout:
|
||||
case <-exitTimeout:
|
||||
log.Println("Etcd: Exiting loop!")
|
||||
cuid.StopTimer() // clean up nicely
|
||||
return
|
||||
@@ -1597,7 +1623,7 @@ func (obj *EmbdEtcd) idealClusterSizeCallback(re *RE) error {
|
||||
log.Printf("Trace: Etcd: idealClusterSizeCallback()")
|
||||
defer log.Printf("Trace: Etcd: idealClusterSizeCallback(): Finished!")
|
||||
}
|
||||
path := fmt.Sprintf("/%s/idealClusterSize", NS)
|
||||
path := fmt.Sprintf("%s/idealClusterSize", NS)
|
||||
for _, event := range re.response.Events {
|
||||
if key := bytes.NewBuffer(event.Kv.Key).String(); key != path {
|
||||
continue
|
||||
|
||||
543
etcd/fs/file.go
Normal file
543
etcd/fs/file.go
Normal file
@@ -0,0 +1,543 @@
|
||||
// Mgmt
|
||||
// Copyright (C) 2013-2018+ 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 <http://www.gnu.org/licenses/>.
|
||||
|
||||
package fs
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"encoding/gob"
|
||||
"fmt"
|
||||
"io"
|
||||
"log"
|
||||
"os"
|
||||
"path"
|
||||
"strings"
|
||||
"syscall"
|
||||
"time"
|
||||
|
||||
etcd "github.com/coreos/etcd/clientv3" // "clientv3"
|
||||
errwrap "github.com/pkg/errors"
|
||||
)
|
||||
|
||||
func init() {
|
||||
gob.Register(&File{})
|
||||
}
|
||||
|
||||
// File represents a file node. This is the node of our tree structure. This is
|
||||
// not thread safe, and you can have at most one open file handle at a time.
|
||||
type File struct {
|
||||
// FIXME: add a rwmutex to make this thread safe
|
||||
fs *Fs // pointer to file system
|
||||
|
||||
Path string // relative path to file, trailing slash if it's a directory
|
||||
Mode os.FileMode
|
||||
ModTime time.Time
|
||||
//Size int64 // XXX: cache the size to avoid full file downloads for stat!
|
||||
|
||||
Children []*File // dir's use this
|
||||
Hash string // string not []byte so it's readable, matches data
|
||||
|
||||
data []byte // cache of the data. private so it doesn't get encoded
|
||||
cursor int64
|
||||
dirCursor int64
|
||||
|
||||
readOnly bool // is the file read-only?
|
||||
closed bool // is file closed?
|
||||
}
|
||||
|
||||
// path returns the expected path to the actual file in etcd.
|
||||
func (obj *File) path() string {
|
||||
// keys are prefixed with the hash-type eg: {sha256} to allow different
|
||||
// superblocks to share the same data prefix even with different hashes
|
||||
return fmt.Sprintf("%s/{%s}%s", obj.fs.sb.DataPrefix, obj.fs.Hash, obj.Hash)
|
||||
}
|
||||
|
||||
// cache downloads the file contents from etcd and stores them in our cache.
|
||||
func (obj *File) cache() error {
|
||||
if obj.Mode.IsDir() {
|
||||
return nil
|
||||
}
|
||||
|
||||
h, err := obj.fs.hash(obj.data) // update hash
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
if h == obj.Hash { // we already have the correct data cached
|
||||
return nil
|
||||
}
|
||||
|
||||
p := obj.path() // get file data from this path in etcd
|
||||
|
||||
result, err := obj.fs.get(p) // download the file...
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
if result == nil || len(result) == 0 { // nothing found
|
||||
return err
|
||||
}
|
||||
data, exists := result[p]
|
||||
if !exists {
|
||||
return fmt.Errorf("could not find data") // programming error?
|
||||
}
|
||||
obj.data = data // save
|
||||
return nil
|
||||
}
|
||||
|
||||
// findNode is the "in array" equivalent for searching through a dir's children.
|
||||
// You must *not* specify an absolute path as the search string, but rather you
|
||||
// should specify the name. To search for something name "bar" inside a dir
|
||||
// named "/tmp/foo/", you just pass in "bar", not "/tmp/foo/bar".
|
||||
func (obj *File) findNode(name string) (*File, bool) {
|
||||
for _, node := range obj.Children {
|
||||
if name == node.Path {
|
||||
return node, true // found
|
||||
}
|
||||
}
|
||||
return nil, false // not found
|
||||
}
|
||||
|
||||
func fileCreate(fs *Fs, name string) (*File, error) {
|
||||
if name == "" {
|
||||
return nil, fmt.Errorf("invalid input path")
|
||||
}
|
||||
if !strings.HasPrefix(name, "/") {
|
||||
return nil, fmt.Errorf("invalid input path (not absolute)")
|
||||
}
|
||||
cleanPath := path.Clean(name) // remove possible trailing slashes
|
||||
|
||||
// try to add node to tree by first finding the parent node
|
||||
parentPath, filePath := path.Split(cleanPath) // looking for this
|
||||
|
||||
node, err := fs.find(parentPath)
|
||||
if err != nil { // might be ErrNotExist
|
||||
return nil, err
|
||||
}
|
||||
|
||||
fi, err := node.Stat()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
if !fi.IsDir() { // is the parent a suitable home?
|
||||
return nil, &os.PathError{Op: "create", Path: name, Err: syscall.ENOTDIR}
|
||||
}
|
||||
|
||||
f, exists := node.findNode(filePath) // does file already exist inside?
|
||||
if exists { // already exists, overwrite!
|
||||
if err := f.Truncate(0); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return f, nil
|
||||
}
|
||||
|
||||
data := []byte("") // empty file contents
|
||||
h, err := fs.hash(data) // TODO: use memoized value?
|
||||
if err != nil {
|
||||
return &File{}, err // TODO: nil instead?
|
||||
}
|
||||
|
||||
f = &File{
|
||||
fs: fs,
|
||||
Path: filePath, // the relative path chunk (not incl. dir name)
|
||||
Hash: h,
|
||||
data: data,
|
||||
}
|
||||
|
||||
// add to parent
|
||||
node.Children = append(node.Children, f)
|
||||
|
||||
// push new file up if not on server, and then push up the metadata
|
||||
if err := f.Sync(); err != nil {
|
||||
return f, err // TODO: ok to return the file so user can run sync?
|
||||
}
|
||||
|
||||
return f, nil
|
||||
}
|
||||
|
||||
func fileOpen(fs *Fs, name string) (*File, error) {
|
||||
if name == "" {
|
||||
return nil, fmt.Errorf("invalid input path")
|
||||
}
|
||||
if !strings.HasPrefix(name, "/") {
|
||||
return nil, fmt.Errorf("invalid input path (not absolute)")
|
||||
}
|
||||
cleanPath := path.Clean(name) // remove possible trailing slashes
|
||||
|
||||
node, err := fs.find(cleanPath)
|
||||
if err != nil { // might be ErrNotExist
|
||||
return &File{}, err // TODO: nil instead?
|
||||
}
|
||||
|
||||
// download file contents into obj.data
|
||||
if err := node.cache(); err != nil {
|
||||
return &File{}, err // TODO: nil instead?
|
||||
}
|
||||
|
||||
//fi, err := node.Stat()
|
||||
//if err != nil {
|
||||
// return nil, err
|
||||
//}
|
||||
//if fi.IsDir() { // can we open a directory? - yes we can apparently
|
||||
// return nil, fmt.Errorf("file is a directory")
|
||||
//}
|
||||
|
||||
node.readOnly = true // as per docs, fileOpen opens files as read-only
|
||||
node.closed = false // as per docs, fileOpen opens files as read-only
|
||||
|
||||
return node, nil
|
||||
}
|
||||
|
||||
// Close closes the file handle. This will try and run Sync automatically.
|
||||
func (obj *File) Close() error {
|
||||
if !obj.readOnly {
|
||||
obj.ModTime = time.Now()
|
||||
}
|
||||
|
||||
if err := obj.Sync(); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// FIXME: there is a big implementation mistake between the metadata
|
||||
// node and the file handle, since they're currently sharing a struct!
|
||||
|
||||
// invalidate all of the fields
|
||||
//obj.fs = nil
|
||||
|
||||
//obj.Path = ""
|
||||
//obj.Mode = os.FileMode(0)
|
||||
//obj.ModTime = time.Time{}
|
||||
|
||||
//obj.Children = nil
|
||||
//obj.Hash = ""
|
||||
|
||||
//obj.data = nil
|
||||
obj.cursor = 0
|
||||
obj.readOnly = false
|
||||
|
||||
obj.closed = true
|
||||
return nil
|
||||
}
|
||||
|
||||
// Name returns the path of the file.
|
||||
func (obj *File) Name() string {
|
||||
return obj.Path
|
||||
}
|
||||
|
||||
// Stat returns some information about the file.
|
||||
func (obj *File) Stat() (os.FileInfo, error) {
|
||||
// download file contents into obj.data
|
||||
if err := obj.cache(); err != nil { // needed so Size() works correctly
|
||||
return nil, err
|
||||
}
|
||||
return &FileInfo{ // everything is actually stored in the main file node
|
||||
file: obj,
|
||||
}, nil
|
||||
}
|
||||
|
||||
// Sync flushes the file contents to the server and calls the filesystem
|
||||
// metadata sync as well.
|
||||
// FIXME: instead of a txn, run a get and then a put in two separate stages. if
|
||||
// the get already found the data up there, then we don't need to push it all in
|
||||
// the put phase. with the txn it is always all sent up even if the put is never
|
||||
// needed. the get should just be a "key exists" test, and not a download of the
|
||||
// whole file. if we *do* do the download, we can byte-by-byte check for hash
|
||||
// collisions and panic if we find one :)
|
||||
func (obj *File) Sync() error {
|
||||
if obj.closed {
|
||||
return ErrFileClosed
|
||||
}
|
||||
|
||||
p := obj.path() // store file data at this path in etcd
|
||||
|
||||
// TODO: use https://github.com/coreos/etcd/pull/7417 if merged
|
||||
cmp := etcd.Compare(etcd.Version(p), "=", 0) // KeyMissing
|
||||
//cmp := etcd.KeyMissing(p))
|
||||
|
||||
op := etcd.OpPut(p, string(obj.data)) // this pushes contents to server
|
||||
|
||||
// it's important to do this in one transaction, and atomically, because
|
||||
// this way, we only generate one watch event, and only when it's needed
|
||||
result, err := obj.fs.txn([]etcd.Cmp{cmp}, []etcd.Op{op}, nil)
|
||||
if err != nil {
|
||||
return errwrap.Wrapf(err, "sync error with: %s (%s)", obj.Path, p)
|
||||
}
|
||||
if !result.Succeeded {
|
||||
if obj.fs.Debug {
|
||||
log.Printf("debug: data already exists in storage")
|
||||
}
|
||||
}
|
||||
|
||||
if err := obj.fs.sync(); err != nil { // push metadata up to server
|
||||
return err
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// Truncate trims the file to the requested size. Since our file system can only
|
||||
// read and write data, but never edit existing data blocks, doing this will not
|
||||
// cause more space to be available.
|
||||
func (obj *File) Truncate(size int64) error {
|
||||
if obj.closed {
|
||||
return ErrFileClosed
|
||||
}
|
||||
if obj.readOnly {
|
||||
return &os.PathError{Op: "truncate", Path: obj.Path, Err: ErrFileReadOnly}
|
||||
}
|
||||
if size < 0 {
|
||||
return ErrOutOfRange
|
||||
}
|
||||
|
||||
if size > 0 { // if size == 0, we don't need to run cache!
|
||||
// download file contents into obj.data
|
||||
if err := obj.cache(); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
|
||||
if size > int64(len(obj.data)) {
|
||||
diff := size - int64(len(obj.data))
|
||||
obj.data = append(obj.data, bytes.Repeat([]byte{00}, int(diff))...)
|
||||
} else {
|
||||
obj.data = obj.data[0:size]
|
||||
}
|
||||
|
||||
h, err := obj.fs.hash(obj.data) // update hash
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
obj.Hash = h
|
||||
obj.ModTime = time.Now()
|
||||
|
||||
// this pushes the new data and metadata up to etcd
|
||||
if err := obj.Sync(); err != nil {
|
||||
return err
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// Read reads up to len(b) bytes from the File. It returns the number of bytes
|
||||
// read and any error encountered. At end of file, Read returns 0, io.EOF.
|
||||
// NOTE: This reads into the byte input. It's a side effect!
|
||||
func (obj *File) Read(b []byte) (n int, err error) {
|
||||
if obj.closed {
|
||||
return 0, ErrFileClosed
|
||||
}
|
||||
if obj.Mode.IsDir() {
|
||||
return 0, fmt.Errorf("file is a directory")
|
||||
}
|
||||
|
||||
// download file contents into obj.data
|
||||
if err := obj.cache(); err != nil {
|
||||
return 0, err // TODO: -1 ?
|
||||
}
|
||||
|
||||
// TODO: can we optimize by reading just the length from etcd, and also
|
||||
// by only downloading the data range we're interested in?
|
||||
if len(b) > 0 && int(obj.cursor) == len(obj.data) {
|
||||
return 0, io.EOF
|
||||
}
|
||||
if len(obj.data)-int(obj.cursor) >= len(b) {
|
||||
n = len(b)
|
||||
} else {
|
||||
n = len(obj.data) - int(obj.cursor)
|
||||
}
|
||||
copy(b, obj.data[obj.cursor:obj.cursor+int64(n)]) // store into input b
|
||||
obj.cursor = obj.cursor + int64(n) // update cursor
|
||||
|
||||
return
|
||||
}
|
||||
|
||||
// ReadAt reads len(b) bytes from the File starting at byte offset off. It
|
||||
// returns the number of bytes read and the error, if any. ReadAt always returns
|
||||
// a non-nil error when n < len(b). At end of file, that error is io.EOF.
|
||||
func (obj *File) ReadAt(b []byte, off int64) (n int, err error) {
|
||||
obj.cursor = off
|
||||
return obj.Read(b)
|
||||
}
|
||||
|
||||
// Readdir lists the contents of the directory and returns a list of file info
|
||||
// objects for each entry.
|
||||
func (obj *File) Readdir(count int) ([]os.FileInfo, error) {
|
||||
if !obj.Mode.IsDir() {
|
||||
return nil, &os.PathError{Op: "readdir", Path: obj.Name(), Err: syscall.ENOTDIR}
|
||||
}
|
||||
|
||||
children := obj.Children[obj.dirCursor:] // available children to output
|
||||
var l = int64(len(children)) // initially assume to return them all
|
||||
var err error
|
||||
|
||||
// for count > 0, if we return the last entry, also return io.EOF
|
||||
if count > 0 {
|
||||
l = int64(count) // initial assumption
|
||||
if c := len(children); count >= c {
|
||||
l = int64(c)
|
||||
err = io.EOF // this result includes the last dir entry
|
||||
}
|
||||
}
|
||||
obj.dirCursor += l // store our progress
|
||||
|
||||
output := make([]os.FileInfo, l)
|
||||
// TODO: should this be sorted by "directory order" what does that mean?
|
||||
// from `man 3 readdir`: "unlikely that the names will be sorted"
|
||||
for i := range output {
|
||||
output[i] = &FileInfo{
|
||||
file: children[i],
|
||||
}
|
||||
}
|
||||
|
||||
// we're seen the whole directory, so reset the cursor
|
||||
if err == io.EOF || count <= 0 {
|
||||
obj.dirCursor = 0 // TODO: is it okay to reset the cursor?
|
||||
}
|
||||
|
||||
return output, err
|
||||
}
|
||||
|
||||
// Readdirnames returns a list of name is the current file handle's directory.
|
||||
// TODO: this implementation shares the dirCursor with Readdir, is this okay?
|
||||
// TODO: should Readdirnames even use a dirCursor at all?
|
||||
func (obj *File) Readdirnames(n int) (names []string, _ error) {
|
||||
fis, err := obj.Readdir(n)
|
||||
if fis != nil {
|
||||
for i, x := range fis {
|
||||
if x != nil {
|
||||
names = append(names, fis[i].Name())
|
||||
}
|
||||
}
|
||||
}
|
||||
return names, err
|
||||
}
|
||||
|
||||
// Seek sets the offset for the next Read or Write on file to offset,
|
||||
// interpreted according to whence: 0 means relative to the origin of the file,
|
||||
// 1 means relative to the current offset, and 2 means relative to the end. It
|
||||
// returns the new offset and an error, if any. The behavior of Seek on a file
|
||||
// opened with O_APPEND is not specified.
|
||||
func (obj *File) Seek(offset int64, whence int) (int64, error) {
|
||||
if obj.closed {
|
||||
return 0, ErrFileClosed
|
||||
}
|
||||
|
||||
switch whence {
|
||||
case io.SeekStart: // 0
|
||||
obj.cursor = offset
|
||||
case io.SeekCurrent: // 1
|
||||
obj.cursor += offset
|
||||
case io.SeekEnd: // 2
|
||||
// download file contents into obj.data
|
||||
if err := obj.cache(); err != nil {
|
||||
return 0, err // TODO: -1 ?
|
||||
}
|
||||
obj.cursor = int64(len(obj.data)) + offset
|
||||
}
|
||||
return obj.cursor, nil
|
||||
}
|
||||
|
||||
// Write writes to the given file.
|
||||
func (obj *File) Write(b []byte) (n int, err error) {
|
||||
if obj.closed {
|
||||
return 0, ErrFileClosed
|
||||
}
|
||||
if obj.readOnly {
|
||||
return 0, &os.PathError{Op: "write", Path: obj.Path, Err: ErrFileReadOnly}
|
||||
}
|
||||
|
||||
// download file contents into obj.data
|
||||
if err := obj.cache(); err != nil {
|
||||
return 0, err // TODO: -1 ?
|
||||
}
|
||||
|
||||
// calculate the write
|
||||
n = len(b)
|
||||
cur := obj.cursor
|
||||
diff := cur - int64(len(obj.data))
|
||||
|
||||
var tail []byte
|
||||
if n+int(cur) < len(obj.data) {
|
||||
tail = obj.data[n+int(cur):]
|
||||
}
|
||||
|
||||
if diff > 0 {
|
||||
obj.data = append(bytes.Repeat([]byte{00}, int(diff)), b...)
|
||||
obj.data = append(obj.data, tail...)
|
||||
} else {
|
||||
obj.data = append(obj.data[:cur], b...)
|
||||
obj.data = append(obj.data, tail...)
|
||||
}
|
||||
|
||||
h, err := obj.fs.hash(obj.data) // update hash
|
||||
if err != nil {
|
||||
return 0, err // TODO: -1 ?
|
||||
}
|
||||
obj.Hash = h
|
||||
obj.ModTime = time.Now()
|
||||
|
||||
// this pushes the new data and metadata up to etcd
|
||||
if err := obj.Sync(); err != nil {
|
||||
return 0, err // TODO: -1 ?
|
||||
}
|
||||
|
||||
obj.cursor = int64(len(obj.data))
|
||||
return
|
||||
}
|
||||
|
||||
// WriteAt writes into the given file at a certain offset.
|
||||
func (obj *File) WriteAt(b []byte, off int64) (n int, err error) {
|
||||
obj.cursor = off
|
||||
return obj.Write(b)
|
||||
}
|
||||
|
||||
// WriteString writes a string to the file.
|
||||
func (obj *File) WriteString(s string) (n int, err error) {
|
||||
return obj.Write([]byte(s))
|
||||
}
|
||||
|
||||
// FileInfo is a struct which provides some information about a file handle.
|
||||
type FileInfo struct {
|
||||
file *File // anonymous pointer to the actual file
|
||||
}
|
||||
|
||||
// Name returns the base name of the file.
|
||||
func (obj *FileInfo) Name() string {
|
||||
return obj.file.Name()
|
||||
}
|
||||
|
||||
// Size returns the length in bytes.
|
||||
func (obj *FileInfo) Size() int64 {
|
||||
return int64(len(obj.file.data))
|
||||
}
|
||||
|
||||
// Mode returns the file mode bits.
|
||||
func (obj *FileInfo) Mode() os.FileMode {
|
||||
return obj.file.Mode
|
||||
}
|
||||
|
||||
// ModTime returns the modification time.
|
||||
func (obj *FileInfo) ModTime() time.Time {
|
||||
return obj.file.ModTime
|
||||
}
|
||||
|
||||
// IsDir is an abbreviation for Mode().IsDir().
|
||||
func (obj *FileInfo) IsDir() bool {
|
||||
//return obj.file.Mode&os.ModeDir != 0
|
||||
return obj.file.Mode.IsDir()
|
||||
}
|
||||
|
||||
// Sys returns the underlying data source (can return nil).
|
||||
func (obj *FileInfo) Sys() interface{} {
|
||||
return nil // TODO: should we do something better?
|
||||
//return obj.file.fs // TODO: would this work?
|
||||
}
|
||||
821
etcd/fs/fs.go
Normal file
821
etcd/fs/fs.go
Normal file
@@ -0,0 +1,821 @@
|
||||
// Mgmt
|
||||
// Copyright (C) 2013-2018+ 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 <http://www.gnu.org/licenses/>.
|
||||
|
||||
// Package fs implements a very simple and limited file system on top of etcd.
|
||||
package fs
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"crypto/sha256"
|
||||
"encoding/gob"
|
||||
"encoding/hex"
|
||||
"errors"
|
||||
"fmt"
|
||||
"hash"
|
||||
"io"
|
||||
"log"
|
||||
"os"
|
||||
"path"
|
||||
"strings"
|
||||
"syscall"
|
||||
"time"
|
||||
|
||||
etcd "github.com/coreos/etcd/clientv3" // "clientv3"
|
||||
rpctypes "github.com/coreos/etcd/etcdserver/api/v3rpc/rpctypes"
|
||||
errwrap "github.com/pkg/errors"
|
||||
"github.com/spf13/afero"
|
||||
context "golang.org/x/net/context"
|
||||
)
|
||||
|
||||
func init() {
|
||||
gob.Register(&superBlock{})
|
||||
}
|
||||
|
||||
const (
|
||||
// EtcdTimeout is the timeout to wait before erroring.
|
||||
EtcdTimeout = 5 * time.Second // FIXME: chosen arbitrarily
|
||||
// DefaultDataPrefix is the default path for data storage in etcd.
|
||||
DefaultDataPrefix = "/_etcdfs/data"
|
||||
// DefaultHash is the default hashing algorithm to use.
|
||||
DefaultHash = "sha256"
|
||||
// PathSeparator is the path separator to use on this filesystem.
|
||||
PathSeparator = os.PathSeparator // usually the slash character
|
||||
)
|
||||
|
||||
// TODO: https://dave.cheney.net/2016/04/07/constant-errors
|
||||
var (
|
||||
IsPathSeparator = os.IsPathSeparator
|
||||
|
||||
// ErrNotImplemented is returned when something is not implemented by design.
|
||||
ErrNotImplemented = errors.New("not implemented")
|
||||
|
||||
// ErrExist is returned when requested path already exists.
|
||||
ErrExist = os.ErrExist
|
||||
|
||||
// ErrNotExist is returned when we can't find the requested path.
|
||||
ErrNotExist = os.ErrNotExist
|
||||
|
||||
ErrFileClosed = errors.New("File is closed")
|
||||
ErrFileReadOnly = errors.New("File handle is read only")
|
||||
ErrOutOfRange = errors.New("Out of range")
|
||||
)
|
||||
|
||||
// Fs is a specialized afero.Fs implementation for etcd. It implements a small
|
||||
// subset of the features, and has some special properties. In particular, file
|
||||
// data is stored with it's unique reference being a hash of the data. In this
|
||||
// way, you cannot actually edit a file, but rather you create a new one, and
|
||||
// update the metadata pointer to point to the new blob. This might seem slow,
|
||||
// but it has the unique advantage of being relatively straight forward to
|
||||
// implement, and repeated uploads of the same file cost almost nothing. Since
|
||||
// etcd isn't meant for large file systems, this fits the desired use case.
|
||||
// This implementation is designed to have a single writer for each superblock,
|
||||
// but as many readers as you like.
|
||||
// FIXME: this is not currently thread-safe, nor is it clear if it needs to be.
|
||||
// XXX: we probably aren't updating the modification time everywhere we should!
|
||||
// XXX: because we never delete data blocks, we need to occasionally "vacuum".
|
||||
// XXX: this is harder because we need to list of *all* metadata paths, if we
|
||||
// want them to be able to share storage backends. (we do)
|
||||
type Fs struct {
|
||||
Client *etcd.Client
|
||||
|
||||
Metadata string // location of "superblock" for this filesystem
|
||||
|
||||
DataPrefix string // prefix of data storage (no trailing slashes)
|
||||
Hash string // eg: sha256
|
||||
|
||||
Debug bool
|
||||
|
||||
sb *superBlock
|
||||
mounted bool
|
||||
}
|
||||
|
||||
// superBlock is the metadata structure of everything stored outside of the data
|
||||
// section in etcd. Its fields need to be exported or they won't get marshalled.
|
||||
type superBlock struct {
|
||||
DataPrefix string // prefix of data storage
|
||||
Hash string // hashing algorithm used
|
||||
|
||||
Tree *File // filesystem tree
|
||||
}
|
||||
|
||||
// NewEtcdFs creates a new filesystem handle on an etcd client connection. You
|
||||
// must specify the metadata string that you wish to use.
|
||||
func NewEtcdFs(client *etcd.Client, metadata string) afero.Fs {
|
||||
return &Fs{
|
||||
Client: client,
|
||||
Metadata: metadata,
|
||||
}
|
||||
}
|
||||
|
||||
// get a number of values from etcd.
|
||||
func (obj *Fs) get(path string, opts ...etcd.OpOption) (map[string][]byte, error) {
|
||||
ctx, cancel := context.WithTimeout(context.Background(), EtcdTimeout)
|
||||
resp, err := obj.Client.Get(ctx, path, opts...)
|
||||
cancel()
|
||||
if err != nil || resp == nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
// TODO: write a resp.ToMap() function on https://godoc.org/github.com/coreos/etcd/etcdserver/etcdserverpb#RangeResponse
|
||||
result := make(map[string][]byte) // formerly: map[string][]byte
|
||||
for _, x := range resp.Kvs {
|
||||
result[string(x.Key)] = x.Value // formerly: bytes.NewBuffer(x.Value).String()
|
||||
}
|
||||
|
||||
return result, nil
|
||||
}
|
||||
|
||||
// put a value into etcd.
|
||||
func (obj *Fs) put(path string, data []byte, opts ...etcd.OpOption) error {
|
||||
ctx, cancel := context.WithTimeout(context.Background(), EtcdTimeout)
|
||||
_, err := obj.Client.Put(ctx, path, string(data), opts...) // TODO: obj.Client.KV ?
|
||||
cancel()
|
||||
if err != nil {
|
||||
switch err {
|
||||
case context.Canceled:
|
||||
return errwrap.Wrapf(err, "ctx canceled")
|
||||
case context.DeadlineExceeded:
|
||||
return errwrap.Wrapf(err, "ctx deadline exceeded")
|
||||
case rpctypes.ErrEmptyKey:
|
||||
return errwrap.Wrapf(err, "client-side error")
|
||||
default:
|
||||
return errwrap.Wrapf(err, "invalid endpoints")
|
||||
}
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// txn runs a txn in etcd.
|
||||
func (obj *Fs) txn(ifcmps []etcd.Cmp, thenops, elseops []etcd.Op) (*etcd.TxnResponse, error) {
|
||||
ctx, cancel := context.WithTimeout(context.Background(), EtcdTimeout)
|
||||
resp, err := obj.Client.Txn(ctx).If(ifcmps...).Then(thenops...).Else(elseops...).Commit()
|
||||
cancel()
|
||||
return resp, err
|
||||
}
|
||||
|
||||
// hash is a small helper that does the hashing for us.
|
||||
func (obj *Fs) hash(input []byte) (string, error) {
|
||||
var h hash.Hash
|
||||
switch obj.Hash {
|
||||
// TODO: add other hashes
|
||||
case "sha256":
|
||||
h = sha256.New()
|
||||
default:
|
||||
return "", fmt.Errorf("hash does not exist")
|
||||
}
|
||||
src := bytes.NewReader(input)
|
||||
if _, err := io.Copy(h, src); err != nil {
|
||||
return "", err
|
||||
}
|
||||
return hex.EncodeToString(h.Sum(nil)), nil
|
||||
}
|
||||
|
||||
// sync overwrites the superblock with whatever version we have stored.
|
||||
func (obj *Fs) sync() error {
|
||||
b := bytes.Buffer{}
|
||||
e := gob.NewEncoder(&b)
|
||||
err := e.Encode(&obj.sb) // pass with &
|
||||
if err != nil {
|
||||
return errwrap.Wrapf(err, "gob failed to encode")
|
||||
}
|
||||
//base64.StdEncoding.EncodeToString(b.Bytes())
|
||||
return obj.put(obj.Metadata, b.Bytes())
|
||||
}
|
||||
|
||||
// mount downloads the initial cache of metadata, including the *file tree.
|
||||
// Since there's no explicit mount API in the afero.Fs interface, we hide this
|
||||
// method inside any operation that might do any real work, and make it
|
||||
// idempotent so that it can be called as much as we want. If there's no
|
||||
// metadata found (superblock) then we create one.
|
||||
func (obj *Fs) mount() error {
|
||||
if obj.mounted {
|
||||
return nil
|
||||
}
|
||||
|
||||
result, err := obj.get(obj.Metadata) // download the metadata...
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
if result == nil || len(result) == 0 { // nothing found, create the fs
|
||||
if obj.Debug {
|
||||
log.Printf("debug: mount: creating new fs at: %s", obj.Metadata)
|
||||
}
|
||||
// trim any trailing slashes from DataPrefix
|
||||
for strings.HasSuffix(obj.DataPrefix, "/") {
|
||||
obj.DataPrefix = strings.TrimSuffix(obj.DataPrefix, "/")
|
||||
}
|
||||
if obj.DataPrefix == "" {
|
||||
obj.DataPrefix = DefaultDataPrefix
|
||||
}
|
||||
if obj.Hash == "" {
|
||||
obj.Hash = DefaultHash
|
||||
}
|
||||
// test run an empty string to see if our hash selection works!
|
||||
if _, err := obj.hash([]byte("")); err != nil {
|
||||
return fmt.Errorf("cannot hash with %s", obj.Hash)
|
||||
}
|
||||
|
||||
obj.sb = &superBlock{
|
||||
DataPrefix: obj.DataPrefix,
|
||||
Hash: obj.Hash,
|
||||
Tree: &File{ // include a root directory
|
||||
fs: obj,
|
||||
Path: "", // root dir is "" (empty string)
|
||||
Mode: os.ModeDir,
|
||||
},
|
||||
}
|
||||
if err := obj.sync(); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
obj.mounted = true
|
||||
return nil
|
||||
}
|
||||
|
||||
if obj.Debug {
|
||||
log.Printf("debug: mount: opening old fs at: %s", obj.Metadata)
|
||||
}
|
||||
sb, exists := result[obj.Metadata]
|
||||
if !exists {
|
||||
return fmt.Errorf("could not find metadata") // programming error?
|
||||
}
|
||||
|
||||
// decode into obj.sb
|
||||
//bb, err := base64.StdEncoding.DecodeString(str)
|
||||
//if err != nil {
|
||||
// return errwrap.Wrapf(err, "base64 failed to decode")
|
||||
//}
|
||||
//b := bytes.NewBuffer(bb)
|
||||
b := bytes.NewBuffer(sb)
|
||||
d := gob.NewDecoder(b)
|
||||
if err := d.Decode(&obj.sb); err != nil { // pass with &
|
||||
return errwrap.Wrapf(err, "gob failed to decode")
|
||||
}
|
||||
|
||||
if obj.DataPrefix != "" && obj.DataPrefix != obj.sb.DataPrefix {
|
||||
return fmt.Errorf("the DataPrefix mount option `%s` does not match the remote value of `%s`", obj.DataPrefix, obj.sb.DataPrefix)
|
||||
}
|
||||
if obj.Hash != "" && obj.Hash != obj.sb.Hash {
|
||||
return fmt.Errorf("the Hash mount option `%s` does not match the remote value of `%s`", obj.Hash, obj.sb.Hash)
|
||||
}
|
||||
// if all checks passed, copy these values down locally
|
||||
obj.DataPrefix = obj.sb.DataPrefix
|
||||
obj.Hash = obj.sb.Hash
|
||||
|
||||
// hook up file system pointers to each element in the tree structure
|
||||
obj.traverse(obj.sb.Tree)
|
||||
|
||||
obj.mounted = true
|
||||
return nil
|
||||
}
|
||||
|
||||
// traverse adds the file system pointer to each element in the tree structure.
|
||||
func (obj *Fs) traverse(node *File) {
|
||||
if node == nil {
|
||||
return
|
||||
}
|
||||
node.fs = obj
|
||||
for _, n := range node.Children {
|
||||
obj.traverse(n)
|
||||
}
|
||||
}
|
||||
|
||||
// find returns the file node corresponding to this absolute path if it exists.
|
||||
func (obj *Fs) find(absPath string) (*File, error) { // TODO: function naming?
|
||||
if absPath == "" {
|
||||
return nil, fmt.Errorf("empty path specified")
|
||||
}
|
||||
if !strings.HasPrefix(absPath, "/") {
|
||||
return nil, fmt.Errorf("invalid input path (not absolute)")
|
||||
}
|
||||
|
||||
node := obj.sb.Tree
|
||||
if node == nil {
|
||||
return nil, ErrNotExist // no nodes exist yet, not even root dir
|
||||
}
|
||||
|
||||
var x string // first value
|
||||
sp := PathSplit(absPath)
|
||||
if x, sp = sp[0], sp[1:]; x != node.Path {
|
||||
return nil, fmt.Errorf("root values do not match") // TODO: panic?
|
||||
}
|
||||
|
||||
for _, p := range sp {
|
||||
n, exists := node.findNode(p)
|
||||
if !exists {
|
||||
return nil, ErrNotExist
|
||||
}
|
||||
node = n // descend into this node
|
||||
}
|
||||
|
||||
return node, nil
|
||||
}
|
||||
|
||||
// Name returns the name of this filesystem.
|
||||
func (obj *Fs) Name() string { return "etcdfs" }
|
||||
|
||||
// URI returns a URI representing this particular filesystem.
|
||||
func (obj *Fs) URI() string {
|
||||
return fmt.Sprintf("%s://%s", obj.Name(), obj.Metadata)
|
||||
}
|
||||
|
||||
// Create creates a new file.
|
||||
func (obj *Fs) Create(name string) (afero.File, error) {
|
||||
if err := obj.mount(); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return fileCreate(obj, name)
|
||||
}
|
||||
|
||||
// Mkdir makes a new directory.
|
||||
func (obj *Fs) Mkdir(name string, perm os.FileMode) error {
|
||||
if err := obj.mount(); err != nil {
|
||||
return err
|
||||
}
|
||||
if name == "" {
|
||||
return fmt.Errorf("invalid input path")
|
||||
}
|
||||
if !strings.HasPrefix(name, "/") {
|
||||
return fmt.Errorf("invalid input path (not absolute)")
|
||||
}
|
||||
|
||||
// remove possible trailing slashes
|
||||
cleanPath := path.Clean(name)
|
||||
|
||||
for strings.HasSuffix(cleanPath, "/") { // bonus clean for "/" as input
|
||||
cleanPath = strings.TrimSuffix(cleanPath, "/")
|
||||
}
|
||||
|
||||
if cleanPath == "" {
|
||||
if obj.sb.Tree == nil {
|
||||
return fmt.Errorf("woops, missing root directory")
|
||||
}
|
||||
return ErrExist // root directory already exists
|
||||
}
|
||||
|
||||
// try to add node to tree by first finding the parent node
|
||||
parentPath, dirPath := path.Split(cleanPath) // looking for this
|
||||
|
||||
f := &File{
|
||||
fs: obj,
|
||||
Path: dirPath,
|
||||
Mode: os.ModeDir,
|
||||
// TODO: add perm to struct or let chmod below do it
|
||||
}
|
||||
|
||||
node, err := obj.find(parentPath)
|
||||
if err != nil { // might be ErrNotExist
|
||||
return err
|
||||
}
|
||||
|
||||
fi, err := node.Stat()
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
if !fi.IsDir() { // is the parent a suitable home?
|
||||
return &os.PathError{Op: "mkdir", Path: name, Err: syscall.ENOTDIR}
|
||||
}
|
||||
|
||||
_, exists := node.findNode(dirPath) // does file already exist inside?
|
||||
if exists {
|
||||
return ErrExist
|
||||
}
|
||||
|
||||
// add to parent
|
||||
node.Children = append(node.Children, f)
|
||||
|
||||
// push new file up if not on server, and then push up the metadata
|
||||
if err := f.Sync(); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
return obj.Chmod(name, perm)
|
||||
}
|
||||
|
||||
// MkdirAll creates a directory named path, along with any necessary parents,
|
||||
// and returns nil, or else returns an error. The permission bits perm are used
|
||||
// for all directories that MkdirAll creates. If path is already a directory,
|
||||
// MkdirAll does nothing and returns nil.
|
||||
func (obj *Fs) MkdirAll(path string, perm os.FileMode) error {
|
||||
if err := obj.mount(); err != nil {
|
||||
return err
|
||||
}
|
||||
// Copied mostly verbatim from golang stdlib.
|
||||
// Fast path: if we can tell whether path is a directory or file, stop
|
||||
// with success or error.
|
||||
dir, err := obj.Stat(path)
|
||||
if err == nil {
|
||||
if dir.IsDir() {
|
||||
return nil
|
||||
}
|
||||
return &os.PathError{Op: "mkdir", Path: path, Err: syscall.ENOTDIR}
|
||||
}
|
||||
|
||||
// Slow path: make sure parent exists and then call Mkdir for path.
|
||||
i := len(path)
|
||||
for i > 0 && IsPathSeparator(path[i-1]) { // Skip trailing path separator.
|
||||
i--
|
||||
}
|
||||
|
||||
j := i
|
||||
for j > 0 && !IsPathSeparator(path[j-1]) { // Scan backward over element.
|
||||
j--
|
||||
}
|
||||
|
||||
if j > 1 {
|
||||
// Create parent
|
||||
err = obj.MkdirAll(path[0:j-1], perm)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
|
||||
// Parent now exists; invoke Mkdir and use its result.
|
||||
err = obj.Mkdir(path, perm)
|
||||
if err != nil {
|
||||
// Handle arguments like "foo/." by
|
||||
// double-checking that directory doesn't exist.
|
||||
dir, err1 := obj.Lstat(path)
|
||||
if err1 == nil && dir.IsDir() {
|
||||
return nil
|
||||
}
|
||||
return err
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// Open opens a path. It will be opened read-only.
|
||||
func (obj *Fs) Open(name string) (afero.File, error) {
|
||||
if err := obj.mount(); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return fileOpen(obj, name) // this opens as read-only
|
||||
}
|
||||
|
||||
// OpenFile opens a path with a particular flag and permission.
|
||||
func (obj *Fs) OpenFile(name string, flag int, perm os.FileMode) (afero.File, error) {
|
||||
if err := obj.mount(); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
chmod := false
|
||||
f, err := fileOpen(obj, name)
|
||||
if os.IsNotExist(err) && (flag&os.O_CREATE > 0) {
|
||||
f, err = fileCreate(obj, name)
|
||||
chmod = true
|
||||
}
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
f.readOnly = (flag == os.O_RDONLY)
|
||||
|
||||
if flag&os.O_APPEND > 0 {
|
||||
if _, err := f.Seek(0, os.SEEK_END); err != nil {
|
||||
f.Close()
|
||||
return nil, err
|
||||
}
|
||||
}
|
||||
if flag&os.O_TRUNC > 0 && flag&(os.O_RDWR|os.O_WRONLY) > 0 {
|
||||
if err := f.Truncate(0); err != nil {
|
||||
f.Close()
|
||||
return nil, err
|
||||
}
|
||||
}
|
||||
if chmod {
|
||||
// TODO: the golang stdlib doesn't check this error, should we?
|
||||
if err := obj.Chmod(name, perm); err != nil {
|
||||
return f, err // TODO: should we return the file handle?
|
||||
}
|
||||
}
|
||||
return f, nil
|
||||
}
|
||||
|
||||
// Remove removes a path.
|
||||
func (obj *Fs) Remove(name string) error {
|
||||
if err := obj.mount(); err != nil {
|
||||
return err
|
||||
}
|
||||
if name == "" {
|
||||
return fmt.Errorf("invalid input path")
|
||||
}
|
||||
if !strings.HasPrefix(name, "/") {
|
||||
return fmt.Errorf("invalid input path (not absolute)")
|
||||
}
|
||||
|
||||
// remove possible trailing slashes
|
||||
cleanPath := path.Clean(name)
|
||||
|
||||
for strings.HasSuffix(cleanPath, "/") { // bonus clean for "/" as input
|
||||
cleanPath = strings.TrimSuffix(cleanPath, "/")
|
||||
}
|
||||
|
||||
if cleanPath == "" {
|
||||
return fmt.Errorf("can't remove root")
|
||||
}
|
||||
|
||||
f, err := obj.find(name) // get the file
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
if len(f.Children) > 0 { // this file or dir has children, can't remove!
|
||||
return &os.PathError{Op: "remove", Path: name, Err: syscall.ENOTEMPTY}
|
||||
}
|
||||
|
||||
// find the parent node
|
||||
parentPath, filePath := path.Split(cleanPath) // looking for this
|
||||
|
||||
node, err := obj.find(parentPath)
|
||||
if err != nil { // might be ErrNotExist
|
||||
if os.IsNotExist(err) { // race! must have just disappeared
|
||||
return nil
|
||||
}
|
||||
return err
|
||||
}
|
||||
|
||||
var index = -1 // int
|
||||
for i, n := range node.Children {
|
||||
if n.Path == filePath {
|
||||
index = i // found here!
|
||||
break
|
||||
}
|
||||
}
|
||||
if index == -1 {
|
||||
return fmt.Errorf("programming error")
|
||||
}
|
||||
// remove from list
|
||||
node.Children = append(node.Children[:index], node.Children[index+1:]...)
|
||||
return obj.sync()
|
||||
}
|
||||
|
||||
// RemoveAll removes path and any children it contains. It removes everything it
|
||||
// can but returns the first error it encounters. If the path does not exist,
|
||||
// RemoveAll returns nil (no error).
|
||||
func (obj *Fs) RemoveAll(path string) error {
|
||||
if err := obj.mount(); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// Simple case: if Remove works, we're done.
|
||||
err := obj.Remove(path)
|
||||
if err == nil || os.IsNotExist(err) {
|
||||
return nil
|
||||
}
|
||||
|
||||
// Otherwise, is this a directory we need to recurse into?
|
||||
dir, serr := obj.Lstat(path)
|
||||
if serr != nil {
|
||||
// TODO: I didn't check this logic thoroughly (edge cases?)
|
||||
if serr, ok := serr.(*os.PathError); ok && (os.IsNotExist(serr.Err) || serr.Err == syscall.ENOTDIR) {
|
||||
return nil
|
||||
}
|
||||
return serr
|
||||
}
|
||||
if !dir.IsDir() {
|
||||
// Not a directory; return the error from Remove.
|
||||
return err
|
||||
}
|
||||
|
||||
// Directory.
|
||||
fd, err := obj.Open(path)
|
||||
if err != nil {
|
||||
if os.IsNotExist(err) {
|
||||
// Race. It was deleted between the Lstat and Open.
|
||||
// Return nil per RemoveAll's docs.
|
||||
return nil
|
||||
}
|
||||
return err
|
||||
}
|
||||
|
||||
// Remove contents & return first error.
|
||||
err = nil
|
||||
for {
|
||||
// TODO: why not do this in one shot? is there a syscall limit?
|
||||
names, err1 := fd.Readdirnames(100)
|
||||
for _, name := range names {
|
||||
err1 := obj.RemoveAll(path + string(PathSeparator) + name)
|
||||
if err == nil {
|
||||
err = err1
|
||||
}
|
||||
}
|
||||
if err1 == io.EOF {
|
||||
break
|
||||
}
|
||||
// If Readdirnames returned an error, use it.
|
||||
if err == nil {
|
||||
err = err1
|
||||
}
|
||||
if len(names) == 0 {
|
||||
break
|
||||
}
|
||||
}
|
||||
|
||||
// Close directory, because windows won't remove opened directory.
|
||||
fd.Close()
|
||||
|
||||
// Remove directory.
|
||||
err1 := obj.Remove(path)
|
||||
if err1 == nil || os.IsNotExist(err1) {
|
||||
return nil
|
||||
}
|
||||
if err == nil {
|
||||
err = err1
|
||||
}
|
||||
return err
|
||||
}
|
||||
|
||||
// Rename moves or renames a file or directory.
|
||||
// TODO: seems it's okay to move files or directories, but you can't clobber dirs
|
||||
// but you can clobber single files. a dir can't clobber a file and a file can't
|
||||
// clobber a dir. but a file can clobber another file but a dir can't clobber
|
||||
// another dir. you can also transplant dirs or files into other dirs.
|
||||
func (obj *Fs) Rename(oldname, newname string) error {
|
||||
// XXX: do we need to check if dest path is inside src path?
|
||||
// XXX: if dirs/files are next to each other, do we mess up the .Children list of the common parent?
|
||||
if err := obj.mount(); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
if oldname == newname {
|
||||
return nil
|
||||
}
|
||||
if oldname == "" || newname == "" {
|
||||
return fmt.Errorf("invalid input path")
|
||||
}
|
||||
if !strings.HasPrefix(oldname, "/") || !strings.HasPrefix(newname, "/") {
|
||||
return fmt.Errorf("invalid input path (not absolute)")
|
||||
}
|
||||
|
||||
// remove possible trailing slashes
|
||||
srcCleanPath := path.Clean(oldname)
|
||||
dstCleanPath := path.Clean(newname)
|
||||
|
||||
src, err := obj.find(srcCleanPath) // get the file
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
srcInfo, err := src.Stat()
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
srcParentPath, srcName := path.Split(srcCleanPath) // looking for this
|
||||
parent, err := obj.find(srcParentPath)
|
||||
if err != nil { // might be ErrNotExist
|
||||
return err
|
||||
}
|
||||
var rmi = -1 // index of node to remove from parent
|
||||
// find the thing to be deleted
|
||||
for i, n := range parent.Children {
|
||||
if n.Path == srcName {
|
||||
rmi = i // found here!
|
||||
break
|
||||
}
|
||||
}
|
||||
if rmi == -1 {
|
||||
return fmt.Errorf("programming error")
|
||||
}
|
||||
|
||||
dst, err := obj.find(dstCleanPath) // does the destination already exist?
|
||||
if err != nil && !os.IsNotExist(err) {
|
||||
return err
|
||||
}
|
||||
if err == nil { // dst exists!
|
||||
dstInfo, err := dst.Stat()
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// dir's can clobber anything or be clobbered apparently
|
||||
if srcInfo.IsDir() || dstInfo.IsDir() {
|
||||
return ErrExist // dir's can't clobber anything
|
||||
}
|
||||
|
||||
// remove from list by index
|
||||
parent.Children = append(parent.Children[:rmi], parent.Children[rmi+1:]...)
|
||||
|
||||
// we're a file clobbering another file...
|
||||
// move file content from src -> dst and then delete src
|
||||
// TODO: run a dst.Close() for extra safety first?
|
||||
save := dst.Path // save the "name"
|
||||
*dst = *src // TODO: is this safe?
|
||||
dst.Path = save // "rename" it
|
||||
|
||||
} else { // dst does not exist
|
||||
|
||||
// check if the dst's parent exists and is a dir, if not, error
|
||||
// if it is a dir, add src as a child to it and then delete src
|
||||
dstParentPath, dstName := path.Split(dstCleanPath) // looking for this
|
||||
node, err := obj.find(dstParentPath)
|
||||
if err != nil { // might be ErrNotExist
|
||||
return err
|
||||
}
|
||||
fi, err := node.Stat()
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
if !fi.IsDir() { // is the parent a suitable home?
|
||||
return &os.LinkError{Op: "rename", Old: oldname, New: newname, Err: syscall.ENOTDIR}
|
||||
}
|
||||
|
||||
// remove from list by index
|
||||
parent.Children = append(parent.Children[:rmi], parent.Children[rmi+1:]...)
|
||||
|
||||
src.Path = dstName // "rename" it
|
||||
node.Children = append(node.Children, src) // "copied"
|
||||
}
|
||||
|
||||
return obj.sync() // push up metadata changes
|
||||
}
|
||||
|
||||
// Stat returns some information about the particular path.
|
||||
func (obj *Fs) Stat(name string) (os.FileInfo, error) {
|
||||
if err := obj.mount(); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
if !strings.HasPrefix(name, "/") {
|
||||
return nil, fmt.Errorf("invalid input path (not absolute)")
|
||||
}
|
||||
|
||||
f, err := obj.find(name) // get the file
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return f.Stat()
|
||||
}
|
||||
|
||||
// Lstat does exactly the same as Stat because we currently do not support
|
||||
// symbolic links.
|
||||
func (obj *Fs) Lstat(name string) (os.FileInfo, error) {
|
||||
if err := obj.mount(); err != nil {
|
||||
return nil, err
|
||||
}
|
||||
// TODO: we don't have symbolic links in our fs, so we pass this to stat
|
||||
return obj.Stat(name)
|
||||
}
|
||||
|
||||
// Chmod changes the mode of a file.
|
||||
func (obj *Fs) Chmod(name string, mode os.FileMode) error {
|
||||
if err := obj.mount(); err != nil {
|
||||
return err
|
||||
}
|
||||
if !strings.HasPrefix(name, "/") {
|
||||
return fmt.Errorf("invalid input path (not absolute)")
|
||||
}
|
||||
|
||||
f, err := obj.find(name) // get the file
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
f.Mode = f.Mode | mode // XXX: what is the correct way to do this?
|
||||
return f.Sync() // push up the changed metadata
|
||||
}
|
||||
|
||||
// Chtimes changes the access and modification times of the named file, similar
|
||||
// to the Unix utime() or utimes() functions. The underlying filesystem may
|
||||
// truncate or round the values to a less precise time unit. If there is an
|
||||
// error, it will be of type *PathError.
|
||||
// FIXME: make sure everything we error is a *PathError
|
||||
// TODO: atime is not currently implement and so it is silently ignored.
|
||||
func (obj *Fs) Chtimes(name string, atime time.Time, mtime time.Time) error {
|
||||
if err := obj.mount(); err != nil {
|
||||
return err
|
||||
}
|
||||
if !strings.HasPrefix(name, "/") {
|
||||
return fmt.Errorf("invalid input path (not absolute)")
|
||||
}
|
||||
|
||||
f, err := obj.find(name) // get the file
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
f.ModTime = mtime
|
||||
// TODO: add atime
|
||||
return f.Sync() // push up the changed metadata
|
||||
}
|
||||
|
||||
// PathSplit splits a path into an array of tokens excluding any trailing empty
|
||||
// tokens.
|
||||
func PathSplit(p string) []string {
|
||||
if p == "/" { // TODO: can't this all be expressed nicely in one line?
|
||||
return []string{""}
|
||||
}
|
||||
return strings.Split(path.Clean(p), "/")
|
||||
}
|
||||
227
etcd/fs/fs_test.go
Normal file
227
etcd/fs/fs_test.go
Normal file
@@ -0,0 +1,227 @@
|
||||
// Mgmt
|
||||
// Copyright (C) 2013-2018+ 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 <http://www.gnu.org/licenses/>.
|
||||
|
||||
package fs_test // named this way to make it easier for examples
|
||||
|
||||
import (
|
||||
"io"
|
||||
"testing"
|
||||
|
||||
"github.com/purpleidea/mgmt/etcd"
|
||||
etcdfs "github.com/purpleidea/mgmt/etcd/fs"
|
||||
"github.com/purpleidea/mgmt/util"
|
||||
|
||||
"github.com/spf13/afero"
|
||||
)
|
||||
|
||||
// XXX: spawn etcd for this test, like `cdtmpmkdir && etcd` and then kill it...
|
||||
// XXX: write a bunch more tests to test this
|
||||
|
||||
// TODO: apparently using 0666 is equivalent to respecting the current umask
|
||||
const (
|
||||
umask = 0666
|
||||
superblock = "/some/superblock" // TODO: generate randomly per test?
|
||||
)
|
||||
|
||||
func TestFs1(t *testing.T) {
|
||||
etcdClient := &etcd.ClientEtcd{
|
||||
Seeds: []string{"localhost:2379"}, // endpoints
|
||||
}
|
||||
|
||||
if err := etcdClient.Connect(); err != nil {
|
||||
t.Logf("client connection error: %+v", err)
|
||||
return
|
||||
}
|
||||
defer etcdClient.Destroy()
|
||||
|
||||
etcdFs := &etcdfs.Fs{
|
||||
Client: etcdClient.GetClient(),
|
||||
Metadata: superblock,
|
||||
DataPrefix: etcdfs.DefaultDataPrefix,
|
||||
}
|
||||
//var etcdFs afero.Fs = NewEtcdFs()
|
||||
|
||||
if err := etcdFs.Mkdir("/", umask); err != nil {
|
||||
t.Logf("error: %+v", err)
|
||||
if err != etcdfs.ErrExist {
|
||||
return
|
||||
}
|
||||
}
|
||||
|
||||
if err := etcdFs.Mkdir("/tmp", umask); err != nil {
|
||||
t.Logf("error: %+v", err)
|
||||
if err != etcdfs.ErrExist {
|
||||
return
|
||||
}
|
||||
}
|
||||
|
||||
fi, err := etcdFs.Stat("/tmp")
|
||||
if err != nil {
|
||||
t.Logf("stat error: %+v", err)
|
||||
return
|
||||
}
|
||||
|
||||
t.Logf("fi: %+v", fi)
|
||||
t.Logf("isdir: %t", fi.IsDir())
|
||||
|
||||
f, err := etcdFs.Create("/tmp/foo")
|
||||
if err != nil {
|
||||
t.Logf("error: %+v", err)
|
||||
return
|
||||
}
|
||||
|
||||
t.Logf("handle: %+v", f)
|
||||
|
||||
i, err := f.WriteString("hello world!\n")
|
||||
if err != nil {
|
||||
t.Logf("error: %+v", err)
|
||||
return
|
||||
}
|
||||
t.Logf("wrote: %d", i)
|
||||
|
||||
if err := etcdFs.Mkdir("/tmp/d1", umask); err != nil {
|
||||
t.Logf("error: %+v", err)
|
||||
if err != etcdfs.ErrExist {
|
||||
return
|
||||
}
|
||||
}
|
||||
|
||||
if err := etcdFs.Rename("/tmp/foo", "/tmp/bar"); err != nil {
|
||||
t.Logf("rename error: %+v", err)
|
||||
return
|
||||
}
|
||||
|
||||
//f2, err := etcdFs.Create("/tmp/bar")
|
||||
//if err != nil {
|
||||
// t.Logf("error: %+v", err)
|
||||
// return
|
||||
//}
|
||||
|
||||
//i2, err := f2.WriteString("hello bar!\n")
|
||||
//if err != nil {
|
||||
// t.Logf("error: %+v", err)
|
||||
// return
|
||||
//}
|
||||
//t.Logf("wrote: %d", i2)
|
||||
|
||||
dir, err := etcdFs.Open("/tmp")
|
||||
if err != nil {
|
||||
t.Logf("error: %+v", err)
|
||||
return
|
||||
}
|
||||
names, err := dir.Readdirnames(-1)
|
||||
if err != nil && err != io.EOF {
|
||||
t.Logf("error: %+v", err)
|
||||
return
|
||||
}
|
||||
for _, name := range names {
|
||||
t.Logf("name in /tmp: %+v", name)
|
||||
}
|
||||
|
||||
//dir, err := etcdFs.Open("/")
|
||||
//if err != nil {
|
||||
// t.Logf("error: %+v", err)
|
||||
// return
|
||||
//}
|
||||
//names, err := dir.Readdirnames(-1)
|
||||
//if err != nil && err != io.EOF {
|
||||
// t.Logf("error: %+v", err)
|
||||
// return
|
||||
//}
|
||||
//for _, name := range names {
|
||||
// t.Logf("name in /: %+v", name)
|
||||
//}
|
||||
}
|
||||
|
||||
func TestFs2(t *testing.T) {
|
||||
etcdClient := &etcd.ClientEtcd{
|
||||
Seeds: []string{"localhost:2379"}, // endpoints
|
||||
}
|
||||
|
||||
if err := etcdClient.Connect(); err != nil {
|
||||
t.Logf("client connection error: %+v", err)
|
||||
return
|
||||
}
|
||||
defer etcdClient.Destroy()
|
||||
|
||||
etcdFs := &etcdfs.Fs{
|
||||
Client: etcdClient.GetClient(),
|
||||
Metadata: superblock,
|
||||
DataPrefix: etcdfs.DefaultDataPrefix,
|
||||
}
|
||||
|
||||
tree, err := util.FsTree(etcdFs, "/")
|
||||
if err != nil {
|
||||
t.Errorf("tree error: %+v", err)
|
||||
return
|
||||
}
|
||||
t.Logf("tree: \n%s", tree)
|
||||
|
||||
tree2, err := util.FsTree(etcdFs, "/tmp")
|
||||
if err != nil {
|
||||
t.Errorf("tree2 error: %+v", err)
|
||||
return
|
||||
}
|
||||
t.Logf("tree2: \n%s", tree2)
|
||||
}
|
||||
|
||||
func TestFs3(t *testing.T) {
|
||||
etcdClient := &etcd.ClientEtcd{
|
||||
Seeds: []string{"localhost:2379"}, // endpoints
|
||||
}
|
||||
|
||||
if err := etcdClient.Connect(); err != nil {
|
||||
t.Logf("client connection error: %+v", err)
|
||||
return
|
||||
}
|
||||
defer etcdClient.Destroy()
|
||||
|
||||
etcdFs := &etcdfs.Fs{
|
||||
Client: etcdClient.GetClient(),
|
||||
Metadata: superblock,
|
||||
DataPrefix: etcdfs.DefaultDataPrefix,
|
||||
}
|
||||
|
||||
tree, err := util.FsTree(etcdFs, "/")
|
||||
if err != nil {
|
||||
t.Errorf("tree error: %+v", err)
|
||||
return
|
||||
}
|
||||
t.Logf("tree: \n%s", tree)
|
||||
|
||||
var memFs afero.Fs = afero.NewMemMapFs()
|
||||
|
||||
if err := util.CopyFs(etcdFs, memFs, "/", "/", false); err != nil {
|
||||
t.Errorf("CopyFs error: %+v", err)
|
||||
return
|
||||
}
|
||||
if err := util.CopyFs(etcdFs, memFs, "/", "/", true); err != nil {
|
||||
t.Errorf("CopyFs2 error: %+v", err)
|
||||
return
|
||||
}
|
||||
if err := util.CopyFs(etcdFs, memFs, "/", "/tmp/d1/", false); err != nil {
|
||||
t.Errorf("CopyFs3 error: %+v", err)
|
||||
return
|
||||
}
|
||||
|
||||
tree2, err := util.FsTree(memFs, "/")
|
||||
if err != nil {
|
||||
t.Errorf("tree2 error: %+v", err)
|
||||
return
|
||||
}
|
||||
t.Logf("tree2: \n%s", tree2)
|
||||
}
|
||||
88
etcd/fs/util.go
Normal file
88
etcd/fs/util.go
Normal file
@@ -0,0 +1,88 @@
|
||||
// Mgmt
|
||||
// Copyright (C) 2013-2018+ 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 <http://www.gnu.org/licenses/>.
|
||||
|
||||
package fs
|
||||
|
||||
import (
|
||||
"os"
|
||||
"path/filepath"
|
||||
|
||||
"github.com/spf13/afero"
|
||||
)
|
||||
|
||||
// ReadAll reads from r until an error or EOF and returns the data it read.
|
||||
// A successful call returns err == nil, not err == EOF. Because ReadAll is
|
||||
// defined to read from src until EOF, it does not treat an EOF from Read
|
||||
// as an error to be reported.
|
||||
//func ReadAll(r io.Reader) ([]byte, error) {
|
||||
// return afero.ReadAll(r)
|
||||
//}
|
||||
|
||||
// ReadDir reads the directory named by dirname and returns
|
||||
// a list of sorted directory entries.
|
||||
func (obj *Fs) ReadDir(dirname string) ([]os.FileInfo, error) {
|
||||
return afero.ReadDir(obj, dirname)
|
||||
}
|
||||
|
||||
// ReadFile reads the file named by filename and returns the contents.
|
||||
// A successful call returns err == nil, not err == EOF. Because ReadFile
|
||||
// reads the whole file, it does not treat an EOF from Read as an error
|
||||
// to be reported.
|
||||
func (obj *Fs) ReadFile(filename string) ([]byte, error) {
|
||||
return afero.ReadFile(obj, filename)
|
||||
}
|
||||
|
||||
// TempDir creates a new temporary directory in the directory dir
|
||||
// with a name beginning with prefix and returns the path of the
|
||||
// new directory. If dir is the empty string, TempDir uses the
|
||||
// default directory for temporary files (see os.TempDir).
|
||||
// Multiple programs calling TempDir simultaneously
|
||||
// will not choose the same directory. It is the caller's responsibility
|
||||
// to remove the directory when no longer needed.
|
||||
func (obj *Fs) TempDir(dir, prefix string) (name string, err error) {
|
||||
return afero.TempDir(obj, dir, prefix)
|
||||
}
|
||||
|
||||
// TempFile creates a new temporary file in the directory dir
|
||||
// with a name beginning with prefix, opens the file for reading
|
||||
// and writing, and returns the resulting *File.
|
||||
// If dir is the empty string, TempFile uses the default directory
|
||||
// for temporary files (see os.TempDir).
|
||||
// Multiple programs calling TempFile simultaneously
|
||||
// will not choose the same file. The caller can use f.Name()
|
||||
// to find the pathname of the file. It is the caller's responsibility
|
||||
// to remove the file when no longer needed.
|
||||
func (obj *Fs) TempFile(dir, prefix string) (f afero.File, err error) {
|
||||
return afero.TempFile(obj, dir, prefix)
|
||||
}
|
||||
|
||||
// WriteFile writes data to a file named by filename.
|
||||
// If the file does not exist, WriteFile creates it with permissions perm;
|
||||
// otherwise WriteFile truncates it before writing.
|
||||
func (obj *Fs) WriteFile(filename string, data []byte, perm os.FileMode) error {
|
||||
return afero.WriteFile(obj, filename, data, perm)
|
||||
}
|
||||
|
||||
// Walk walks the file tree rooted at root, calling walkFn for each file or
|
||||
// directory in the tree, including root. All errors that arise visiting files
|
||||
// and directories are filtered by walkFn. The files are walked in lexical
|
||||
// order, which makes the output deterministic but means that for very
|
||||
// large directories Walk can be inefficient.
|
||||
// Walk does not follow symbolic links.
|
||||
func (obj *Fs) Walk(root string, walkFn filepath.WalkFunc) error {
|
||||
return afero.Walk(obj, root, walkFn)
|
||||
}
|
||||
30
etcd/interfaces.go
Normal file
30
etcd/interfaces.go
Normal file
@@ -0,0 +1,30 @@
|
||||
// Mgmt
|
||||
// Copyright (C) 2013-2018+ 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 <http://www.gnu.org/licenses/>.
|
||||
|
||||
package etcd
|
||||
|
||||
import (
|
||||
etcd "github.com/coreos/etcd/clientv3" // "clientv3"
|
||||
)
|
||||
|
||||
// Client provides a simple interface specification for client requests. Both
|
||||
// EmbdEtcd and ClientEtcd implement this.
|
||||
type Client interface {
|
||||
// TODO: add more method signatures
|
||||
Get(path string, opts ...etcd.OpOption) (map[string]string, error)
|
||||
Txn(ifcmps []etcd.Cmp, thenops, elseops []etcd.Op) (*etcd.TxnResponse, error)
|
||||
}
|
||||
@@ -39,7 +39,7 @@ func Nominate(obj *EmbdEtcd, hostname string, urls etcdtypes.URLs) error {
|
||||
defer log.Printf("Trace: Etcd: Nominate(%v): Finished!", hostname)
|
||||
}
|
||||
// nominate someone to be a server
|
||||
nominate := fmt.Sprintf("/%s/nominated/%s", NS, hostname)
|
||||
nominate := fmt.Sprintf("%s/nominated/%s", NS, hostname)
|
||||
ops := []etcd.Op{} // list of ops in this txn
|
||||
if urls != nil {
|
||||
ops = append(ops, etcd.OpPut(nominate, urls.String())) // TODO: add a TTL? (etcd.WithLease)
|
||||
@@ -57,7 +57,7 @@ func Nominate(obj *EmbdEtcd, hostname string, urls etcdtypes.URLs) error {
|
||||
// Nominated returns a urls map of nominated etcd server volunteers.
|
||||
// NOTE: I know 'nominees' might be more correct, but is less consistent here
|
||||
func Nominated(obj *EmbdEtcd) (etcdtypes.URLsMap, error) {
|
||||
path := fmt.Sprintf("/%s/nominated/", NS)
|
||||
path := fmt.Sprintf("%s/nominated/", NS)
|
||||
keyMap, err := obj.Get(path, etcd.WithPrefix()) // map[string]string, bool
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("nominated isn't available: %v", err)
|
||||
@@ -90,7 +90,7 @@ func Volunteer(obj *EmbdEtcd, urls etcdtypes.URLs) error {
|
||||
defer log.Printf("Trace: Etcd: Volunteer(%v): Finished!", obj.hostname)
|
||||
}
|
||||
// volunteer to be a server
|
||||
volunteer := fmt.Sprintf("/%s/volunteers/%s", NS, obj.hostname)
|
||||
volunteer := fmt.Sprintf("%s/volunteers/%s", NS, obj.hostname)
|
||||
ops := []etcd.Op{} // list of ops in this txn
|
||||
if urls != nil {
|
||||
// XXX: adding a TTL is crucial! (i think)
|
||||
@@ -112,7 +112,7 @@ func Volunteers(obj *EmbdEtcd) (etcdtypes.URLsMap, error) {
|
||||
log.Printf("Trace: Etcd: Volunteers()")
|
||||
defer log.Printf("Trace: Etcd: Volunteers(): Finished!")
|
||||
}
|
||||
path := fmt.Sprintf("/%s/volunteers/", NS)
|
||||
path := fmt.Sprintf("%s/volunteers/", NS)
|
||||
keyMap, err := obj.Get(path, etcd.WithPrefix())
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("volunteers aren't available: %v", err)
|
||||
@@ -145,7 +145,7 @@ func AdvertiseEndpoints(obj *EmbdEtcd, urls etcdtypes.URLs) error {
|
||||
defer log.Printf("Trace: Etcd: AdvertiseEndpoints(%v): Finished!", obj.hostname)
|
||||
}
|
||||
// advertise endpoints
|
||||
endpoints := fmt.Sprintf("/%s/endpoints/%s", NS, obj.hostname)
|
||||
endpoints := fmt.Sprintf("%s/endpoints/%s", NS, obj.hostname)
|
||||
ops := []etcd.Op{} // list of ops in this txn
|
||||
if urls != nil {
|
||||
// TODO: add a TTL? (etcd.WithLease)
|
||||
@@ -167,7 +167,7 @@ func Endpoints(obj *EmbdEtcd) (etcdtypes.URLsMap, error) {
|
||||
log.Printf("Trace: Etcd: Endpoints()")
|
||||
defer log.Printf("Trace: Etcd: Endpoints(): Finished!")
|
||||
}
|
||||
path := fmt.Sprintf("/%s/endpoints/", NS)
|
||||
path := fmt.Sprintf("%s/endpoints/", NS)
|
||||
keyMap, err := obj.Get(path, etcd.WithPrefix())
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("endpoints aren't available: %v", err)
|
||||
@@ -199,7 +199,7 @@ func SetHostnameConverged(obj *EmbdEtcd, hostname string, isConverged bool) erro
|
||||
log.Printf("Trace: Etcd: SetHostnameConverged(%s): %v", hostname, isConverged)
|
||||
defer log.Printf("Trace: Etcd: SetHostnameConverged(%v): Finished!", hostname)
|
||||
}
|
||||
converged := fmt.Sprintf("/%s/converged/%s", NS, hostname)
|
||||
converged := fmt.Sprintf("%s/converged/%s", NS, hostname)
|
||||
op := []etcd.Op{etcd.OpPut(converged, fmt.Sprintf("%t", isConverged))}
|
||||
if _, err := obj.Txn(nil, op, nil); err != nil { // TODO: do we need a skipConv flag here too?
|
||||
return fmt.Errorf("set converged failed") // exit in progress?
|
||||
@@ -213,7 +213,7 @@ func HostnameConverged(obj *EmbdEtcd) (map[string]bool, error) {
|
||||
log.Printf("Trace: Etcd: HostnameConverged()")
|
||||
defer log.Printf("Trace: Etcd: HostnameConverged(): Finished!")
|
||||
}
|
||||
path := fmt.Sprintf("/%s/converged/", NS)
|
||||
path := fmt.Sprintf("%s/converged/", NS)
|
||||
keyMap, err := obj.ComplexGet(path, true, etcd.WithPrefix()) // don't un-converge
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("converged values aren't available: %v", err)
|
||||
@@ -239,7 +239,7 @@ func HostnameConverged(obj *EmbdEtcd) (map[string]bool, error) {
|
||||
// AddHostnameConvergedWatcher adds a watcher with a callback that runs on
|
||||
// hostname state changes.
|
||||
func AddHostnameConvergedWatcher(obj *EmbdEtcd, callbackFn func(map[string]bool) error) (func(), error) {
|
||||
path := fmt.Sprintf("/%s/converged/", NS)
|
||||
path := fmt.Sprintf("%s/converged/", NS)
|
||||
internalCbFn := func(re *RE) error {
|
||||
// TODO: get the value from the response, and apply delta...
|
||||
// for now, just run a get operation which is easier to code!
|
||||
@@ -258,7 +258,7 @@ func SetClusterSize(obj *EmbdEtcd, value uint16) error {
|
||||
log.Printf("Trace: Etcd: SetClusterSize(): %v", value)
|
||||
defer log.Printf("Trace: Etcd: SetClusterSize(): Finished!")
|
||||
}
|
||||
key := fmt.Sprintf("/%s/idealClusterSize", NS)
|
||||
key := fmt.Sprintf("%s/idealClusterSize", NS)
|
||||
|
||||
if err := obj.Set(key, strconv.FormatUint(uint64(value), 10)); err != nil {
|
||||
return fmt.Errorf("function SetClusterSize failed: %v", err) // exit in progress?
|
||||
@@ -268,7 +268,7 @@ func SetClusterSize(obj *EmbdEtcd, value uint16) error {
|
||||
|
||||
// GetClusterSize gets the ideal target cluster size of etcd peers.
|
||||
func GetClusterSize(obj *EmbdEtcd) (uint16, error) {
|
||||
key := fmt.Sprintf("/%s/idealClusterSize", NS)
|
||||
key := fmt.Sprintf("%s/idealClusterSize", NS)
|
||||
keyMap, err := obj.Get(key)
|
||||
if err != nil {
|
||||
return 0, fmt.Errorf("function GetClusterSize failed: %v", err)
|
||||
|
||||
@@ -34,7 +34,7 @@ import (
|
||||
// collection prefixes and filters that we care about...
|
||||
func WatchResources(obj *EmbdEtcd) chan error {
|
||||
ch := make(chan error, 1) // buffer it so we can measure it
|
||||
path := fmt.Sprintf("/%s/exported/", NS)
|
||||
path := fmt.Sprintf("%s/exported/", NS)
|
||||
callback := func(re *RE) error {
|
||||
// TODO: is this even needed? it used to happen on conn errors
|
||||
log.Printf("Etcd: Watch: Path: %v", path) // event
|
||||
@@ -61,7 +61,7 @@ func WatchResources(obj *EmbdEtcd) chan error {
|
||||
|
||||
// SetResources exports all of the resources which we pass in to etcd.
|
||||
func SetResources(obj *EmbdEtcd, hostname string, resourceList []resources.Res) error {
|
||||
// key structure is /$NS/exported/$hostname/resources/$uid = $data
|
||||
// key structure is $NS/exported/$hostname/resources/$uid = $data
|
||||
|
||||
var kindFilter []string // empty to get from everyone
|
||||
hostnameFilter := []string{hostname}
|
||||
@@ -83,7 +83,7 @@ func SetResources(obj *EmbdEtcd, hostname string, resourceList []resources.Res)
|
||||
log.Fatalf("Etcd: SetResources: Error: Empty kind: %v", res.GetName())
|
||||
}
|
||||
uid := fmt.Sprintf("%s/%s", res.GetKind(), res.GetName())
|
||||
path := fmt.Sprintf("/%s/exported/%s/resources/%s", NS, hostname, uid)
|
||||
path := fmt.Sprintf("%s/exported/%s/resources/%s", NS, hostname, uid)
|
||||
if data, err := resources.ResToB64(res); err == nil {
|
||||
ifs = append(ifs, etcd.Compare(etcd.Value(path), "=", data)) // desired state
|
||||
ops = append(ops, etcd.OpPut(path, data))
|
||||
@@ -108,7 +108,7 @@ func SetResources(obj *EmbdEtcd, hostname string, resourceList []resources.Res)
|
||||
log.Fatalf("Etcd: SetResources: Error: Empty kind: %v", res.GetName())
|
||||
}
|
||||
uid := fmt.Sprintf("%s/%s", res.GetKind(), res.GetName())
|
||||
path := fmt.Sprintf("/%s/exported/%s/resources/%s", NS, hostname, uid)
|
||||
path := fmt.Sprintf("%s/exported/%s/resources/%s", NS, hostname, uid)
|
||||
|
||||
if match(res, resourceList) { // if we match, no need to delete!
|
||||
continue
|
||||
@@ -134,10 +134,10 @@ func SetResources(obj *EmbdEtcd, hostname string, resourceList []resources.Res)
|
||||
// If the kindfilter or hostnameFilter is empty, then it assumes no filtering...
|
||||
// TODO: Expand this with a more powerful filter based on what we eventually
|
||||
// support in our collect DSL. Ideally a server side filter like WithFilter()
|
||||
// We could do this if the pattern was /$NS/exported/$kind/$hostname/$uid = $data.
|
||||
// We could do this if the pattern was $NS/exported/$kind/$hostname/$uid = $data.
|
||||
func GetResources(obj *EmbdEtcd, hostnameFilter, kindFilter []string) ([]resources.Res, error) {
|
||||
// key structure is /$NS/exported/$hostname/resources/$uid = $data
|
||||
path := fmt.Sprintf("/%s/exported/", NS)
|
||||
// key structure is $NS/exported/$hostname/resources/$uid = $data
|
||||
path := fmt.Sprintf("%s/exported/", NS)
|
||||
resourceList := []resources.Res{}
|
||||
keyMap, err := obj.Get(path, etcd.WithPrefix(), etcd.WithSort(etcd.SortByKey, etcd.SortAscend))
|
||||
if err != nil {
|
||||
|
||||
49
etcd/scheduler/alphastrategy.go
Normal file
49
etcd/scheduler/alphastrategy.go
Normal file
@@ -0,0 +1,49 @@
|
||||
// Mgmt
|
||||
// Copyright (C) 2013-2018+ 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 <http://www.gnu.org/licenses/>.
|
||||
|
||||
package scheduler // TODO: i'd like this to be a separate package, but cycles!
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"sort"
|
||||
)
|
||||
|
||||
func init() {
|
||||
Register("alpha", func() Strategy { return &alphaStrategy{} }) // must register the func and name
|
||||
}
|
||||
|
||||
type alphaStrategy struct {
|
||||
// no state to store
|
||||
}
|
||||
|
||||
// Schedule returns the first host out of a sorted group of available hostnames.
|
||||
func (obj *alphaStrategy) Schedule(hostnames map[string]string, opts *schedulerOptions) ([]string, error) {
|
||||
if len(hostnames) <= 0 {
|
||||
return nil, fmt.Errorf("strategy: cannot schedule from zero hosts")
|
||||
}
|
||||
if opts.maxCount <= 0 {
|
||||
return nil, fmt.Errorf("strategy: cannot schedule with a max of zero")
|
||||
}
|
||||
|
||||
sortedHosts := []string{}
|
||||
for key := range hostnames {
|
||||
sortedHosts = append(sortedHosts, key)
|
||||
}
|
||||
sort.Strings(sortedHosts)
|
||||
|
||||
return []string{sortedHosts[0]}, nil // pick first host
|
||||
}
|
||||
100
etcd/scheduler/options.go
Normal file
100
etcd/scheduler/options.go
Normal file
@@ -0,0 +1,100 @@
|
||||
// Mgmt
|
||||
// Copyright (C) 2013-2018+ 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 <http://www.gnu.org/licenses/>.
|
||||
|
||||
package scheduler
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
)
|
||||
|
||||
// Option is a type that can be used to configure the scheduler.
|
||||
type Option func(*schedulerOptions)
|
||||
|
||||
// schedulerOptions represents the different possible configurable options. Not
|
||||
// all options necessarily work for each scheduler strategy algorithm.
|
||||
type schedulerOptions struct {
|
||||
debug bool
|
||||
logf func(format string, v ...interface{})
|
||||
strategy Strategy
|
||||
maxCount int // TODO: should this be *int to know when it's set?
|
||||
reuseLease bool
|
||||
sessionTTL int // TODO: should this be *int to know when it's set?
|
||||
hostsFilter []string
|
||||
// TODO: add more options
|
||||
}
|
||||
|
||||
// Debug specifies whether we should run in debug mode or not.
|
||||
func Debug(debug bool) Option {
|
||||
return func(so *schedulerOptions) {
|
||||
so.debug = debug
|
||||
}
|
||||
}
|
||||
|
||||
// Logf passes a logger function that we can use if so desired.
|
||||
func Logf(logf func(format string, v ...interface{})) Option {
|
||||
return func(so *schedulerOptions) {
|
||||
so.logf = logf
|
||||
}
|
||||
}
|
||||
|
||||
// StrategyKind sets the scheduler strategy used.
|
||||
func StrategyKind(strategy string) Option {
|
||||
return func(so *schedulerOptions) {
|
||||
f, exists := registeredStrategies[strategy]
|
||||
if !exists {
|
||||
panic(fmt.Sprintf("scheduler: undefined strategy: %s", strategy))
|
||||
}
|
||||
so.strategy = f()
|
||||
}
|
||||
}
|
||||
|
||||
// MaxCount is the maximum number of hosts that should get simultaneously
|
||||
// scheduled.
|
||||
func MaxCount(maxCount int) Option {
|
||||
return func(so *schedulerOptions) {
|
||||
if maxCount > 0 {
|
||||
so.maxCount = maxCount
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// ReuseLease specifies whether we should try and re-use the lease between runs.
|
||||
// Ordinarily it would get discarded with each new version (deploy) of the code.
|
||||
func ReuseLease(reuseLease bool) Option {
|
||||
return func(so *schedulerOptions) {
|
||||
so.reuseLease = reuseLease
|
||||
}
|
||||
}
|
||||
|
||||
// SessionTTL is the amount of time to delay before expiring a key on abrupt
|
||||
// host disconnect of if ReuseLease is true.
|
||||
func SessionTTL(sessionTTL int) Option {
|
||||
return func(so *schedulerOptions) {
|
||||
if sessionTTL > 0 {
|
||||
so.sessionTTL = sessionTTL
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// HostsFilter specifies a manual list of hosts, to use as a subset of whatever
|
||||
// was auto-discovered.
|
||||
// XXX: think more about this idea...
|
||||
func HostsFilter(hosts []string) Option {
|
||||
return func(so *schedulerOptions) {
|
||||
so.hostsFilter = hosts
|
||||
}
|
||||
}
|
||||
84
etcd/scheduler/rrstrategy.go
Normal file
84
etcd/scheduler/rrstrategy.go
Normal file
@@ -0,0 +1,84 @@
|
||||
// Mgmt
|
||||
// Copyright (C) 2013-2018+ 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 <http://www.gnu.org/licenses/>.
|
||||
|
||||
package scheduler // TODO: i'd like this to be a separate package, but cycles!
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"sort"
|
||||
|
||||
"github.com/purpleidea/mgmt/util"
|
||||
)
|
||||
|
||||
func init() {
|
||||
Register("rr", func() Strategy { return &rrStrategy{} }) // must register the func and name
|
||||
}
|
||||
|
||||
type rrStrategy struct {
|
||||
// some stored state
|
||||
hosts []string
|
||||
}
|
||||
|
||||
// Schedule returns hosts in round robin style from the available hostnames.
|
||||
func (obj *rrStrategy) Schedule(hostnames map[string]string, opts *schedulerOptions) ([]string, error) {
|
||||
if len(hostnames) <= 0 {
|
||||
return nil, fmt.Errorf("strategy: cannot schedule from zero hosts")
|
||||
}
|
||||
if opts.maxCount <= 0 {
|
||||
return nil, fmt.Errorf("strategy: cannot schedule with a max of zero")
|
||||
}
|
||||
|
||||
// always get a deterministic list of current hosts first...
|
||||
sortedHosts := []string{}
|
||||
for key := range hostnames {
|
||||
sortedHosts = append(sortedHosts, key)
|
||||
}
|
||||
sort.Strings(sortedHosts)
|
||||
|
||||
if obj.hosts == nil {
|
||||
obj.hosts = []string{} // initialize if needed
|
||||
}
|
||||
|
||||
// add any new hosts we learned about, to the end of the list
|
||||
for _, x := range sortedHosts {
|
||||
if !util.StrInList(x, obj.hosts) {
|
||||
obj.hosts = append(obj.hosts, x)
|
||||
}
|
||||
}
|
||||
|
||||
// remove any hosts we previouly knew about from the list
|
||||
for ix := len(obj.hosts) - 1; ix >= 0; ix-- {
|
||||
if !util.StrInList(obj.hosts[ix], sortedHosts) {
|
||||
// delete entry at this index
|
||||
obj.hosts = append(obj.hosts[:ix], obj.hosts[ix+1:]...)
|
||||
}
|
||||
}
|
||||
|
||||
// get the maximum number of hosts to return
|
||||
max := len(obj.hosts) // can't return more than we have
|
||||
if opts.maxCount < max { // found a smaller limit
|
||||
max = opts.maxCount
|
||||
}
|
||||
|
||||
result := []string{}
|
||||
// now return the number of needed hosts from the list
|
||||
for i := 0; i < max; i++ {
|
||||
result = append(result, obj.hosts[i])
|
||||
}
|
||||
|
||||
return result, nil
|
||||
}
|
||||
570
etcd/scheduler/scheduler.go
Normal file
570
etcd/scheduler/scheduler.go
Normal file
@@ -0,0 +1,570 @@
|
||||
// Mgmt
|
||||
// Copyright (C) 2013-2018+ 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 <http://www.gnu.org/licenses/>.
|
||||
|
||||
// Package scheduler implements a distributed consensus scheduler with etcd.
|
||||
package scheduler
|
||||
|
||||
import (
|
||||
"context"
|
||||
"errors"
|
||||
"fmt"
|
||||
"sort"
|
||||
"strings"
|
||||
"sync"
|
||||
|
||||
etcd "github.com/coreos/etcd/clientv3"
|
||||
"github.com/coreos/etcd/clientv3/concurrency"
|
||||
pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
|
||||
errwrap "github.com/pkg/errors"
|
||||
)
|
||||
|
||||
const (
|
||||
// DefaultSessionTTL is the number of seconds to wait before a dead or
|
||||
// unresponsive host is removed from the scheduled pool.
|
||||
DefaultSessionTTL = 10 // seconds
|
||||
|
||||
// DefaultMaxCount is the maximum number of hosts to schedule on if not
|
||||
// specified.
|
||||
DefaultMaxCount = 1 // TODO: what is the logical value to choose? +Inf?
|
||||
|
||||
hostnameJoinChar = "," // char used to join and split lists of hostnames
|
||||
)
|
||||
|
||||
// ErrEndOfResults is a sentinel that represents no more results will be coming.
|
||||
var ErrEndOfResults = errors.New("scheduler: end of results")
|
||||
|
||||
var schedulerLeases = make(map[string]etcd.LeaseID) // process lifetime in-memory lease store
|
||||
|
||||
// schedulerResult represents output from the scheduler.
|
||||
type schedulerResult struct {
|
||||
hosts []string
|
||||
err error
|
||||
}
|
||||
|
||||
// Result is what is returned when you request a scheduler. You can call methods
|
||||
// on it, and it stores the necessary state while you're running. When one of
|
||||
// these is produced, the scheduler has already kicked off running for you
|
||||
// automatically.
|
||||
type Result struct {
|
||||
results chan *schedulerResult
|
||||
closeFunc func() // run this when you're done with the scheduler // TODO: replace with an input `context`
|
||||
}
|
||||
|
||||
// Next returns the next output from the scheduler when it changes. This blocks
|
||||
// until a new value is available, which is why you may wish to use a context to
|
||||
// cancel any read from this. It returns ErrEndOfResults if the scheduler shuts
|
||||
// down.
|
||||
func (obj *Result) Next(ctx context.Context) ([]string, error) {
|
||||
select {
|
||||
case val, ok := <-obj.results:
|
||||
if !ok {
|
||||
return nil, ErrEndOfResults
|
||||
}
|
||||
return val.hosts, val.err
|
||||
|
||||
case <-ctx.Done():
|
||||
return nil, ctx.Err()
|
||||
}
|
||||
}
|
||||
|
||||
// Shutdown causes everything to clean up. We no longer need the scheduler.
|
||||
// TODO: should this be named Close() instead? Should it return an error?
|
||||
func (obj *Result) Shutdown() {
|
||||
obj.closeFunc()
|
||||
// XXX: should we have a waitgroup to wait for it all to close?
|
||||
}
|
||||
|
||||
// TODO: use: https://github.com/coreos/etcd/pull/8488 when available
|
||||
func leaseValue(key string) etcd.Cmp {
|
||||
return etcd.Cmp{Key: []byte(key), Target: pb.Compare_LEASE}
|
||||
}
|
||||
|
||||
// Schedule returns a scheduler result which can be queried with it's available
|
||||
// methods. This automatically causes different etcd clients sharing the same
|
||||
// path to discover each other and be part of the scheduled set. On close the
|
||||
// keys expire and will get removed from the scheduled set. Different options
|
||||
// can be passed in to customize the behaviour. Hostname represents the unique
|
||||
// identifier for the caller. The behaviour is undefined if this is run more
|
||||
// than once with the same path and hostname simultaneously.
|
||||
func Schedule(client *etcd.Client, path string, hostname string, opts ...Option) (*Result, error) {
|
||||
if strings.HasSuffix(path, "/") {
|
||||
return nil, fmt.Errorf("scheduler: path must not end with the slash char")
|
||||
}
|
||||
if !strings.HasPrefix(path, "/") {
|
||||
return nil, fmt.Errorf("scheduler: path must start with the slash char")
|
||||
}
|
||||
if hostname == "" {
|
||||
return nil, fmt.Errorf("scheduler: hostname must not be empty")
|
||||
}
|
||||
if strings.Contains(hostname, hostnameJoinChar) {
|
||||
return nil, fmt.Errorf("scheduler: hostname must not contain join char: %s", hostnameJoinChar)
|
||||
}
|
||||
|
||||
// key structure is $path/election = ???
|
||||
// key structure is $path/exchange/$hostname = ???
|
||||
// key structure is $path/scheduled = ???
|
||||
|
||||
options := &schedulerOptions{ // default scheduler options
|
||||
// If reuseLease is false, then on host disconnect, that hosts
|
||||
// entry will immediately expire, and the scheduler will react
|
||||
// instantly and remove that host entry from the list. If this
|
||||
// is true, or if the host closes without a clean shutdown, it
|
||||
// will take the TTL number of seconds to remove the key. This
|
||||
// can be set using the concurrency.WithTTL option to Session.
|
||||
reuseLease: false,
|
||||
sessionTTL: DefaultSessionTTL,
|
||||
maxCount: DefaultMaxCount,
|
||||
}
|
||||
for _, optionFunc := range opts { // apply the scheduler options
|
||||
optionFunc(options)
|
||||
}
|
||||
|
||||
if options.strategy == nil {
|
||||
return nil, fmt.Errorf("scheduler: strategy must be specified")
|
||||
}
|
||||
|
||||
sessionOptions := []concurrency.SessionOption{}
|
||||
|
||||
// here we try to re-use lease between multiple runs of the code
|
||||
// TODO: is it a good idea to try and re-use the lease b/w runs?
|
||||
if options.reuseLease {
|
||||
if leaseID, exists := schedulerLeases[path]; exists {
|
||||
sessionOptions = append(sessionOptions, concurrency.WithLease(leaseID))
|
||||
}
|
||||
}
|
||||
// ttl for key expiry on abrupt disconnection or if reuseLease is true!
|
||||
if options.sessionTTL > 0 {
|
||||
sessionOptions = append(sessionOptions, concurrency.WithTTL(options.sessionTTL))
|
||||
}
|
||||
|
||||
//options.debug = true // use this for local debugging
|
||||
session, err := concurrency.NewSession(client, sessionOptions...)
|
||||
if err != nil {
|
||||
return nil, errwrap.Wrapf(err, "scheduler: could not create session")
|
||||
}
|
||||
leaseID := session.Lease()
|
||||
if options.reuseLease {
|
||||
// save for next time, otherwise run session.Close() somewhere
|
||||
schedulerLeases[path] = leaseID
|
||||
}
|
||||
|
||||
ctx, cancel := context.WithCancel(context.Background()) // cancel below
|
||||
//defer cancel() // do NOT do this, as it would cause an early cancel!
|
||||
|
||||
// stored scheduler results
|
||||
scheduledPath := fmt.Sprintf("%s/scheduled", path)
|
||||
scheduledChan := client.Watcher.Watch(ctx, scheduledPath)
|
||||
|
||||
// exchange hostname, and attach it to session (leaseID) so it expires
|
||||
// (gets deleted) when we disconnect...
|
||||
exchangePath := fmt.Sprintf("%s/exchange", path)
|
||||
exchangePathHost := fmt.Sprintf("%s/%s", exchangePath, hostname)
|
||||
exchangePathPrefix := fmt.Sprintf("%s/", exchangePath)
|
||||
|
||||
// open the watch *before* we set our key so that we can see the change!
|
||||
watchChan := client.Watcher.Watch(ctx, exchangePathPrefix, etcd.WithPrefix())
|
||||
|
||||
data := "TODO" // XXX: no data to exchange alongside hostnames yet
|
||||
ifops := []etcd.Cmp{
|
||||
etcd.Compare(etcd.Value(exchangePathHost), "=", data),
|
||||
etcd.Compare(leaseValue(exchangePathHost), "=", int64(leaseID)), // XXX: remove int64() after 3.3.0
|
||||
}
|
||||
elsop := etcd.OpPut(exchangePathHost, data, etcd.WithLease(leaseID))
|
||||
|
||||
// it's important to do this in one transaction, and atomically, because
|
||||
// this way, we only generate one watch event, and only when it's needed
|
||||
// updating leaseID, or key expiry (deletion) both generate watch events
|
||||
// XXX: context!!!
|
||||
if txn, err := client.KV.Txn(context.TODO()).If(ifops...).Then([]etcd.Op{}...).Else(elsop).Commit(); err != nil {
|
||||
defer cancel() // cancel to avoid leaks if we exit early...
|
||||
return nil, errwrap.Wrapf(err, "could not exchange in `%s`", path)
|
||||
} else if txn.Succeeded {
|
||||
options.logf("txn did nothing...") // then branch
|
||||
} else {
|
||||
options.logf("txn did an update...")
|
||||
}
|
||||
|
||||
// create an election object
|
||||
electionPath := fmt.Sprintf("%s/election", path)
|
||||
election := concurrency.NewElection(session, electionPath)
|
||||
electionChan := election.Observe(ctx)
|
||||
|
||||
elected := "" // who we "assume" is elected
|
||||
wg := &sync.WaitGroup{}
|
||||
ch := make(chan *schedulerResult)
|
||||
closeChan := make(chan struct{})
|
||||
send := func(hosts []string, err error) bool { // helper function for sending
|
||||
select {
|
||||
case ch <- &schedulerResult{ // send
|
||||
hosts: hosts,
|
||||
err: err,
|
||||
}:
|
||||
return true
|
||||
case <-closeChan: // unblock
|
||||
return false // not sent
|
||||
}
|
||||
}
|
||||
|
||||
once := &sync.Once{}
|
||||
onceBody := func() { // do not call directly, use closeFunc!
|
||||
//cancel() // TODO: is this needed here?
|
||||
// request a graceful shutdown, caller must call this to
|
||||
// shutdown when they are finished with the scheduler...
|
||||
// calling this will cause their hosts channels to close
|
||||
close(closeChan) // send a close signal
|
||||
}
|
||||
closeFunc := func() {
|
||||
once.Do(onceBody)
|
||||
}
|
||||
result := &Result{
|
||||
results: ch,
|
||||
// TODO: we could accept a context to watch for cancel instead?
|
||||
closeFunc: closeFunc,
|
||||
}
|
||||
|
||||
mutex := &sync.Mutex{}
|
||||
var campaignClose chan struct{}
|
||||
var campaignRunning bool
|
||||
// goroutine to vote for someone as scheduler! each participant must be
|
||||
// able to run this or nobody will be around to vote if others are down
|
||||
campaignFunc := func() {
|
||||
options.logf("starting campaign...")
|
||||
// the mutex ensures we don't fly past the wg.Wait() if someone
|
||||
// shuts down the scheduler right as we are about to start this
|
||||
// campaigning loop up. we do not want to fail unnecessarily...
|
||||
mutex.Lock()
|
||||
wg.Add(1)
|
||||
mutex.Unlock()
|
||||
go func() {
|
||||
defer wg.Done()
|
||||
|
||||
ctx, cancel := context.WithCancel(context.Background())
|
||||
go func() {
|
||||
defer cancel() // run cancel to stop campaigning...
|
||||
select {
|
||||
case <-campaignClose:
|
||||
return
|
||||
case <-closeChan:
|
||||
return
|
||||
}
|
||||
}()
|
||||
for {
|
||||
// TODO: previously, this looped infinitely fast
|
||||
// TODO: add some rate limiting here for initial
|
||||
// campaigning which occasionally loops a lot...
|
||||
if options.debug {
|
||||
//fmt.Printf(".") // debug
|
||||
options.logf("campaigning...")
|
||||
}
|
||||
|
||||
// "Campaign puts a value as eligible for the election.
|
||||
// It blocks until it is elected, an error occurs, or
|
||||
// the context is cancelled."
|
||||
|
||||
// vote for ourselves, as it's the only host we can
|
||||
// guarantee is alive, otherwise we wouldn't be voting!
|
||||
// it would be more sensible to vote for the last valid
|
||||
// hostname to keep things more stable, but if that
|
||||
// information was stale, and that host wasn't alive,
|
||||
// then this would defeat the point of picking them!
|
||||
if err := election.Campaign(ctx, hostname); err != nil {
|
||||
if err != context.Canceled {
|
||||
send(nil, errwrap.Wrapf(err, "scheduler: error campaigning"))
|
||||
}
|
||||
return
|
||||
}
|
||||
}
|
||||
}()
|
||||
}
|
||||
|
||||
go func() {
|
||||
defer close(ch)
|
||||
if !options.reuseLease {
|
||||
defer session.Close() // this revokes the lease...
|
||||
}
|
||||
|
||||
defer func() {
|
||||
// XXX: should we ever resign? why would this block and thus need a context?
|
||||
if elected == hostname { // TODO: is it safe to just always do this?
|
||||
if err := election.Resign(context.TODO()); err != nil { // XXX: add a timeout?
|
||||
}
|
||||
}
|
||||
elected = "" // we don't care anymore!
|
||||
}()
|
||||
|
||||
// this "last" defer (first to run) should block until the other
|
||||
// goroutine has closed so we don't Close an in-use session, etc
|
||||
defer wg.Wait()
|
||||
|
||||
go func() {
|
||||
defer cancel() // run cancel to "free" Observe...
|
||||
|
||||
defer wg.Wait() // also wait here if parent exits first
|
||||
|
||||
select {
|
||||
case <-closeChan:
|
||||
// we want the above wg.Wait() to work if this
|
||||
// close happens. lock with the campaign start
|
||||
defer mutex.Unlock()
|
||||
mutex.Lock()
|
||||
return
|
||||
}
|
||||
}()
|
||||
hostnames := make(map[string]string)
|
||||
for {
|
||||
select {
|
||||
case val, ok := <-electionChan:
|
||||
if options.debug {
|
||||
options.logf("electionChan(%t): %+v", ok, val)
|
||||
}
|
||||
if !ok {
|
||||
if options.debug {
|
||||
options.logf("elections stream shutdown...")
|
||||
}
|
||||
electionChan = nil
|
||||
// done
|
||||
// TODO: do we need to send on error channel?
|
||||
// XXX: maybe if context was not called to exit us?
|
||||
|
||||
// ensure everyone waiting on closeChan
|
||||
// gets cleaned up so we free mem, etc!
|
||||
if watchChan == nil && scheduledChan == nil { // all now closed
|
||||
closeFunc()
|
||||
return
|
||||
}
|
||||
continue
|
||||
|
||||
}
|
||||
|
||||
elected = string(val.Kvs[0].Value)
|
||||
//if options.debug {
|
||||
options.logf("elected: %s", elected)
|
||||
//}
|
||||
if elected != hostname { // not me!
|
||||
// start up the campaign function
|
||||
if !campaignRunning {
|
||||
campaignClose = make(chan struct{})
|
||||
campaignFunc() // run
|
||||
campaignRunning = true
|
||||
}
|
||||
continue // someone else does the scheduling...
|
||||
} else { // campaigning while i am it loops fast
|
||||
// shutdown the campaign function
|
||||
if campaignRunning {
|
||||
close(campaignClose)
|
||||
wg.Wait()
|
||||
campaignRunning = false
|
||||
}
|
||||
}
|
||||
|
||||
// i was voted in to make the scheduling choice!
|
||||
|
||||
case watchResp, ok := <-watchChan:
|
||||
if options.debug {
|
||||
options.logf("watchChan(%t): %+v", ok, watchResp)
|
||||
}
|
||||
if !ok {
|
||||
if options.debug {
|
||||
options.logf("watch stream shutdown...")
|
||||
}
|
||||
watchChan = nil
|
||||
// done
|
||||
// TODO: do we need to send on error channel?
|
||||
// XXX: maybe if context was not called to exit us?
|
||||
|
||||
// ensure everyone waiting on closeChan
|
||||
// gets cleaned up so we free mem, etc!
|
||||
if electionChan == nil && scheduledChan == nil { // all now closed
|
||||
closeFunc()
|
||||
return
|
||||
}
|
||||
continue
|
||||
}
|
||||
|
||||
err := watchResp.Err()
|
||||
if watchResp.Canceled || err == context.Canceled {
|
||||
// channel get closed shortly...
|
||||
continue
|
||||
}
|
||||
if watchResp.Header.Revision == 0 { // by inspection
|
||||
// received empty message ?
|
||||
// switched client connection ?
|
||||
// FIXME: what should we do here ?
|
||||
continue
|
||||
}
|
||||
if err != nil {
|
||||
send(nil, errwrap.Wrapf(err, "scheduler: exchange watcher failed"))
|
||||
continue
|
||||
}
|
||||
if len(watchResp.Events) == 0 { // nothing interesting
|
||||
continue
|
||||
}
|
||||
|
||||
options.logf("running exchange values get...")
|
||||
resp, err := client.Get(ctx, exchangePathPrefix, etcd.WithPrefix(), etcd.WithSort(etcd.SortByKey, etcd.SortAscend))
|
||||
if err != nil || resp == nil {
|
||||
if err != nil {
|
||||
send(nil, errwrap.Wrapf(err, "scheduler: could not get exchange values in `%s`", path))
|
||||
} else { // if resp == nil
|
||||
send(nil, fmt.Errorf("scheduler: could not get exchange values in `%s`, resp is nil", path))
|
||||
}
|
||||
continue
|
||||
}
|
||||
|
||||
// FIXME: the value key could instead be host
|
||||
// specific information which is used for some
|
||||
// purpose, eg: seconds active, and other data?
|
||||
hostnames = make(map[string]string) // reset
|
||||
for _, x := range resp.Kvs {
|
||||
k := string(x.Key)
|
||||
if !strings.HasPrefix(k, exchangePathPrefix) {
|
||||
continue
|
||||
}
|
||||
k = k[len(exchangePathPrefix):] // strip
|
||||
hostnames[k] = string(x.Value)
|
||||
}
|
||||
if options.debug {
|
||||
options.logf("available hostnames: %+v", hostnames)
|
||||
}
|
||||
|
||||
case scheduledResp, ok := <-scheduledChan:
|
||||
if options.debug {
|
||||
options.logf("scheduledChan(%t): %+v", ok, scheduledResp)
|
||||
}
|
||||
if !ok {
|
||||
if options.debug {
|
||||
options.logf("scheduled stream shutdown...")
|
||||
}
|
||||
scheduledChan = nil
|
||||
// done
|
||||
// TODO: do we need to send on error channel?
|
||||
// XXX: maybe if context was not called to exit us?
|
||||
|
||||
// ensure everyone waiting on closeChan
|
||||
// gets cleaned up so we free mem, etc!
|
||||
if electionChan == nil && watchChan == nil { // all now closed
|
||||
closeFunc()
|
||||
return
|
||||
}
|
||||
continue
|
||||
}
|
||||
// event! continue below and get new result...
|
||||
|
||||
// NOTE: not needed, exit this via Observe ctx cancel,
|
||||
// which will ultimately cause the chan to shutdown...
|
||||
//case <-closeChan:
|
||||
// return
|
||||
} // end select
|
||||
|
||||
if len(hostnames) == 0 {
|
||||
if options.debug {
|
||||
options.logf("zero hosts available")
|
||||
}
|
||||
continue // not enough hosts available
|
||||
}
|
||||
|
||||
// if we're currently elected, make a scheduling decision
|
||||
// if not, lookup the existing leader scheduling decision
|
||||
if elected != hostname {
|
||||
options.logf("i am not the leader, running scheduling result get...")
|
||||
resp, err := client.Get(ctx, scheduledPath)
|
||||
if err != nil || resp == nil || len(resp.Kvs) != 1 {
|
||||
if err != nil {
|
||||
send(nil, errwrap.Wrapf(err, "scheduler: could not get scheduling result in `%s`", path))
|
||||
} else if resp == nil {
|
||||
send(nil, fmt.Errorf("scheduler: could not get scheduling result in `%s`, resp is nil", path))
|
||||
} else if len(resp.Kvs) > 1 {
|
||||
send(nil, fmt.Errorf("scheduler: could not get scheduling result in `%s`, resp kvs: %+v", path, resp.Kvs))
|
||||
}
|
||||
// if len(resp.Kvs) == 0, we shouldn't error
|
||||
// in that situation it's just too early...
|
||||
continue
|
||||
}
|
||||
|
||||
result := string(resp.Kvs[0].Value)
|
||||
hosts := strings.Split(result, hostnameJoinChar)
|
||||
|
||||
if options.debug {
|
||||
options.logf("sending hosts: %+v", hosts)
|
||||
}
|
||||
// send that on channel!
|
||||
if !send(hosts, nil) {
|
||||
//return // pass instead, let channels clean up
|
||||
}
|
||||
continue
|
||||
}
|
||||
|
||||
// i am the leader, run scheduler and store result
|
||||
options.logf("i am elected, running scheduler...")
|
||||
|
||||
// run actual scheduler and decide who should be chosen
|
||||
// TODO: is there any additional data that we can pass
|
||||
// to the scheduler so it can make a better decision ?
|
||||
hosts, err := options.strategy.Schedule(hostnames, options)
|
||||
if err != nil {
|
||||
send(nil, errwrap.Wrapf(err, "scheduler: strategy failed"))
|
||||
continue
|
||||
}
|
||||
sort.Strings(hosts) // for consistency
|
||||
|
||||
options.logf("storing scheduling result...")
|
||||
data := strings.Join(hosts, hostnameJoinChar)
|
||||
ifops := []etcd.Cmp{
|
||||
etcd.Compare(etcd.Value(scheduledPath), "=", data),
|
||||
}
|
||||
elsop := etcd.OpPut(scheduledPath, data)
|
||||
|
||||
// it's important to do this in one transaction, and atomically, because
|
||||
// this way, we only generate one watch event, and only when it's needed
|
||||
// updating leaseID, or key expiry (deletion) both generate watch events
|
||||
// XXX: context!!!
|
||||
if _, err := client.KV.Txn(context.TODO()).If(ifops...).Then([]etcd.Op{}...).Else(elsop).Commit(); err != nil {
|
||||
send(nil, errwrap.Wrapf(err, "scheduler: could not set scheduling result in `%s`", path))
|
||||
continue
|
||||
}
|
||||
|
||||
if options.debug {
|
||||
options.logf("sending hosts: %+v", hosts)
|
||||
}
|
||||
// send that on channel!
|
||||
if !send(hosts, nil) {
|
||||
//return // pass instead, let channels clean up
|
||||
}
|
||||
}
|
||||
}()
|
||||
|
||||
// kick off an initial campaign if none exist already...
|
||||
options.logf("checking for existing leader...")
|
||||
leaderResult, err := election.Leader(ctx)
|
||||
if err == concurrency.ErrElectionNoLeader {
|
||||
// start up the campaign function
|
||||
if !campaignRunning {
|
||||
campaignClose = make(chan struct{})
|
||||
campaignFunc() // run
|
||||
campaignRunning = true
|
||||
}
|
||||
}
|
||||
if options.debug {
|
||||
if err != nil {
|
||||
options.logf("leader information error: %+v", err)
|
||||
} else {
|
||||
options.logf("leader information: %+v", leaderResult)
|
||||
}
|
||||
}
|
||||
|
||||
return result, nil
|
||||
}
|
||||
51
etcd/scheduler/strategy.go
Normal file
51
etcd/scheduler/strategy.go
Normal file
@@ -0,0 +1,51 @@
|
||||
// Mgmt
|
||||
// Copyright (C) 2013-2018+ 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 <http://www.gnu.org/licenses/>.
|
||||
|
||||
package scheduler
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
)
|
||||
|
||||
// registeredStrategies is a global map of all possible strategy implementations
|
||||
// which can be used. You should never touch this map directly. Use methods like
|
||||
// Register instead.
|
||||
var registeredStrategies = make(map[string]func() Strategy) // must initialize
|
||||
|
||||
// Strategy represents the methods a scheduler strategy must implement.
|
||||
type Strategy interface {
|
||||
Schedule(hostnames map[string]string, opts *schedulerOptions) ([]string, error)
|
||||
}
|
||||
|
||||
// Register takes a func and its name and makes it available for use. It is
|
||||
// commonly called in the init() method of the func at program startup. There is
|
||||
// no matching Unregister function.
|
||||
func Register(name string, fn func() Strategy) {
|
||||
if _, ok := registeredStrategies[name]; ok {
|
||||
panic(fmt.Sprintf("a strategy named %s is already registered", name))
|
||||
}
|
||||
//gob.Register(fn())
|
||||
registeredStrategies[name] = fn
|
||||
}
|
||||
|
||||
type nilStrategy struct {
|
||||
}
|
||||
|
||||
// Schedule returns an error for any scheduling request for this nil strategy.
|
||||
func (obj *nilStrategy) Schedule(hostnames map[string]string, opts *schedulerOptions) ([]string, error) {
|
||||
return nil, fmt.Errorf("scheduler: cannot schedule with nil scheduler")
|
||||
}
|
||||
16
etcd/str.go
16
etcd/str.go
@@ -32,9 +32,13 @@ var ErrNotExist = errors.New("errNotExist")
|
||||
// WatchStr returns a channel which spits out events on key activity.
|
||||
// FIXME: It should close the channel when it's done, and spit out errors when
|
||||
// something goes wrong.
|
||||
// XXX: since the caller of this (via the World API) has no way to tell it it's
|
||||
// done, does that mean we leak go-routines since it might still be running, but
|
||||
// perhaps even blocked??? Could this cause a dead-lock? Should we instead return
|
||||
// some sort of struct which has a close method with it to ask for a shutdown?
|
||||
func WatchStr(obj *EmbdEtcd, key string) chan error {
|
||||
// new key structure is /$NS/strings/$key = $data
|
||||
path := fmt.Sprintf("/%s/strings/%s", NS, key)
|
||||
// new key structure is $NS/strings/$key = $data
|
||||
path := fmt.Sprintf("%s/strings/%s", NS, key)
|
||||
ch := make(chan error, 1)
|
||||
// FIXME: fix our API so that we get a close event on shutdown.
|
||||
callback := func(re *RE) error {
|
||||
@@ -54,8 +58,8 @@ func WatchStr(obj *EmbdEtcd, key string) chan error {
|
||||
|
||||
// GetStr collects the string which matches a global namespace in etcd.
|
||||
func GetStr(obj *EmbdEtcd, key string) (string, error) {
|
||||
// new key structure is /$NS/strings/$key = $data
|
||||
path := fmt.Sprintf("/%s/strings/%s", NS, key)
|
||||
// new key structure is $NS/strings/$key = $data
|
||||
path := fmt.Sprintf("%s/strings/%s", NS, key)
|
||||
keyMap, err := obj.Get(path, etcd.WithPrefix())
|
||||
if err != nil {
|
||||
return "", errwrap.Wrapf(err, "could not get strings in: %s", key)
|
||||
@@ -82,8 +86,8 @@ func GetStr(obj *EmbdEtcd, key string) (string, error) {
|
||||
// nil, then it deletes the key. Otherwise the value should point to a string.
|
||||
// TODO: TTL or delete disconnect?
|
||||
func SetStr(obj *EmbdEtcd, key string, data *string) error {
|
||||
// key structure is /$NS/strings/$key = $data
|
||||
path := fmt.Sprintf("/%s/strings/%s", NS, key)
|
||||
// key structure is $NS/strings/$key = $data
|
||||
path := fmt.Sprintf("%s/strings/%s", NS, key)
|
||||
ifs := []etcd.Cmp{} // list matching the desired state
|
||||
ops := []etcd.Op{} // list of ops in this transaction (then)
|
||||
els := []etcd.Op{} // list of ops in this transaction (else)
|
||||
|
||||
@@ -31,8 +31,8 @@ import (
|
||||
// FIXME: It should close the channel when it's done, and spit out errors when
|
||||
// something goes wrong.
|
||||
func WatchStrMap(obj *EmbdEtcd, key string) chan error {
|
||||
// new key structure is /$NS/strings/$key/$hostname = $data
|
||||
path := fmt.Sprintf("/%s/strings/%s", NS, key)
|
||||
// new key structure is $NS/strings/$key/$hostname = $data
|
||||
path := fmt.Sprintf("%s/strings/%s", NS, key)
|
||||
ch := make(chan error, 1)
|
||||
// FIXME: fix our API so that we get a close event on shutdown.
|
||||
callback := func(re *RE) error {
|
||||
@@ -52,12 +52,12 @@ func WatchStrMap(obj *EmbdEtcd, key string) chan error {
|
||||
|
||||
// GetStrMap collects all of the strings which match a namespace in etcd.
|
||||
func GetStrMap(obj *EmbdEtcd, hostnameFilter []string, key string) (map[string]string, error) {
|
||||
// old key structure is /$NS/strings/$hostname/$key = $data
|
||||
// new key structure is /$NS/strings/$key/$hostname = $data
|
||||
// old key structure is $NS/strings/$hostname/$key = $data
|
||||
// new key structure is $NS/strings/$key/$hostname = $data
|
||||
// FIXME: if we have the $key as the last token (old key structure), we
|
||||
// can allow the key to contain the slash char, otherwise we need to
|
||||
// verify that one isn't present in the input string.
|
||||
path := fmt.Sprintf("/%s/strings/%s", NS, key)
|
||||
path := fmt.Sprintf("%s/strings/%s", NS, key)
|
||||
keyMap, err := obj.Get(path, etcd.WithPrefix(), etcd.WithSort(etcd.SortByKey, etcd.SortAscend))
|
||||
if err != nil {
|
||||
return nil, errwrap.Wrapf(err, "could not get strings in: %s", key)
|
||||
@@ -92,8 +92,8 @@ func GetStrMap(obj *EmbdEtcd, hostnameFilter []string, key string) (map[string]s
|
||||
// nil, then it deletes the key. Otherwise the value should point to a string.
|
||||
// TODO: TTL or delete disconnect?
|
||||
func SetStrMap(obj *EmbdEtcd, hostname, key string, data *string) error {
|
||||
// key structure is /$NS/strings/$key/$hostname = $data
|
||||
path := fmt.Sprintf("/%s/strings/%s/%s", NS, key, hostname)
|
||||
// key structure is $NS/strings/$key/$hostname = $data
|
||||
path := fmt.Sprintf("%s/strings/%s/%s", NS, key, hostname)
|
||||
ifs := []etcd.Cmp{} // list matching the desired state
|
||||
ops := []etcd.Op{} // list of ops in this transaction (then)
|
||||
els := []etcd.Op{} // list of ops in this transaction (else)
|
||||
|
||||
@@ -18,13 +18,24 @@
|
||||
package etcd
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"net/url"
|
||||
"strings"
|
||||
|
||||
etcdfs "github.com/purpleidea/mgmt/etcd/fs"
|
||||
"github.com/purpleidea/mgmt/etcd/scheduler"
|
||||
"github.com/purpleidea/mgmt/resources"
|
||||
)
|
||||
|
||||
// World is an etcd backed implementation of the World interface.
|
||||
type World struct {
|
||||
Hostname string // uuid for the consumer of these
|
||||
EmbdEtcd *EmbdEtcd
|
||||
Hostname string // uuid for the consumer of these
|
||||
EmbdEtcd *EmbdEtcd
|
||||
MetadataPrefix string // expected metadata prefix
|
||||
StoragePrefix string // storage prefix for etcdfs storage
|
||||
StandaloneFs resources.Fs // store an fs here for local usage
|
||||
Debug bool
|
||||
Logf func(format string, v ...interface{})
|
||||
}
|
||||
|
||||
// ResWatch returns a channel which spits out events on possible exported
|
||||
@@ -93,3 +104,49 @@ func (obj *World) StrMapSet(namespace, value string) error {
|
||||
func (obj *World) StrMapDel(namespace string) error {
|
||||
return SetStrMap(obj.EmbdEtcd, obj.Hostname, namespace, nil)
|
||||
}
|
||||
|
||||
// Scheduler returns a scheduling result of hosts in a particular namespace.
|
||||
func (obj *World) Scheduler(namespace string, opts ...scheduler.Option) (*scheduler.Result, error) {
|
||||
modifiedOpts := []scheduler.Option{}
|
||||
for _, o := range opts {
|
||||
modifiedOpts = append(modifiedOpts, o) // copy in
|
||||
}
|
||||
|
||||
modifiedOpts = append(modifiedOpts, scheduler.Debug(obj.Debug))
|
||||
modifiedOpts = append(modifiedOpts, scheduler.Logf(obj.Logf))
|
||||
|
||||
return scheduler.Schedule(obj.EmbdEtcd.GetClient(), fmt.Sprintf("%s/scheduler/%s", NS, namespace), obj.Hostname, modifiedOpts...)
|
||||
}
|
||||
|
||||
// Fs returns a distributed file system from a unique URI. For single host
|
||||
// execution that doesn't span more than a single host, this file system might
|
||||
// actually be a local or memory backed file system, so actually only
|
||||
// distributed within the boredom that is a single host cluster.
|
||||
func (obj *World) Fs(uri string) (resources.Fs, error) {
|
||||
u, err := url.Parse(uri)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
// we're in standalone mode
|
||||
if u.Scheme == "memmapfs" && u.Path == "/" {
|
||||
return obj.StandaloneFs, nil
|
||||
}
|
||||
|
||||
if u.Scheme != "etcdfs" {
|
||||
return nil, fmt.Errorf("unknown scheme: `%s`", u.Scheme)
|
||||
}
|
||||
if u.Path == "" {
|
||||
return nil, fmt.Errorf("empty path: %s", u.Path)
|
||||
}
|
||||
if !strings.HasPrefix(u.Path, obj.MetadataPrefix) {
|
||||
return nil, fmt.Errorf("wrong path prefix: %s", u.Path)
|
||||
}
|
||||
|
||||
etcdFs := &etcdfs.Fs{
|
||||
Client: obj.EmbdEtcd.GetClient(),
|
||||
Metadata: u.Path,
|
||||
DataPrefix: obj.StoragePrefix,
|
||||
}
|
||||
return etcdFs, nil
|
||||
}
|
||||
|
||||
22
examples/lang/contains0.mcl
Normal file
22
examples/lang/contains0.mcl
Normal file
@@ -0,0 +1,22 @@
|
||||
$set = ["a", "b", "c", "d",]
|
||||
|
||||
$c1 = "x1" in ["x1", "x2", "x3",]
|
||||
$c2 = 42 in [4, 13, 42,]
|
||||
$c3 = "x" in $set
|
||||
$c4 = "b" in $set
|
||||
|
||||
$s = printf("1: %t, 2: %t, 3: %t, 4: %t\n", $c1, $c2, $c3, $c4)
|
||||
|
||||
file "/tmp/mgmt/contains" {
|
||||
content => $s,
|
||||
}
|
||||
|
||||
$x = if hostname() in ["h1", "h3",] {
|
||||
printf("i (%s) am one of the chosen few!\n", hostname())
|
||||
} else {
|
||||
printf("i (%s) was not chosen :(\n", hostname())
|
||||
}
|
||||
|
||||
file "/tmp/mgmt/hello-${hostname()}" {
|
||||
content => $x,
|
||||
}
|
||||
4
examples/lang/datetime1.mcl
Normal file
4
examples/lang/datetime1.mcl
Normal file
@@ -0,0 +1,4 @@
|
||||
$d = datetime()
|
||||
file "/tmp/mgmt/datetime" {
|
||||
content => template("Hello! It is now: {{ datetimeprint . }}\n", $d),
|
||||
}
|
||||
14
examples/lang/datetime2.mcl
Normal file
14
examples/lang/datetime2.mcl
Normal file
@@ -0,0 +1,14 @@
|
||||
$secplusone = datetime() + $ayear
|
||||
|
||||
# note the order of the assignment (year can come later in the code)
|
||||
$ayear = 60 * 60 * 24 * 365 # is a year in seconds (31536000)
|
||||
|
||||
$tmplvalues = struct{year => $secplusone, load => $theload,}
|
||||
|
||||
$theload = structlookup(load(), "x1")
|
||||
|
||||
if 5 > 3 {
|
||||
file "/tmp/mgmt/datetime" {
|
||||
content => template("Now + 1 year is: {{ .year }} seconds, aka: {{ datetimeprint .year }}\n\nload average: {{ .load }}\n", $tmplvalues),
|
||||
}
|
||||
}
|
||||
14
examples/lang/datetime3.mcl
Normal file
14
examples/lang/datetime3.mcl
Normal file
@@ -0,0 +1,14 @@
|
||||
$secplusone = datetime() + $ayear
|
||||
|
||||
# note the order of the assignment (year can come later in the code)
|
||||
$ayear = 60 * 60 * 24 * 365 # is a year in seconds (31536000)
|
||||
|
||||
$tmplvalues = struct{year => $secplusone, load => $theload, vumeter => $vumeter,}
|
||||
|
||||
$theload = structlookup(load(), "x1")
|
||||
|
||||
$vumeter = vumeter("====", 10, 0.9)
|
||||
|
||||
file "/tmp/mgmt/datetime" {
|
||||
content => template("Now + 1 year is: {{ .year }} seconds, aka: {{ datetimeprint .year }}\n\nload average: {{ .load }}\n\nvu: {{ .vumeter }}\n", $tmplvalues),
|
||||
}
|
||||
13
examples/lang/exchange0.mcl
Normal file
13
examples/lang/exchange0.mcl
Normal file
@@ -0,0 +1,13 @@
|
||||
# run this example with these commands
|
||||
# watch -n 0.1 'tail *' # run this in /tmp/mgmt/
|
||||
# time ./mgmt run --lang examples/lang/exchange0.mcl --hostname h1 --ideal-cluster-size 1 --tmp-prefix --no-pgp
|
||||
# time ./mgmt run --lang examples/lang/exchange0.mcl --hostname h2 --seeds http://127.0.0.1:2379 --client-urls http://127.0.0.1:2381 --server-urls http://127.0.0.1:2382 --tmp-prefix --no-pgp
|
||||
# time ./mgmt run --lang examples/lang/exchange0.mcl --hostname h3 --seeds http://127.0.0.1:2379 --client-urls http://127.0.0.1:2383 --server-urls http://127.0.0.1:2384 --tmp-prefix --no-pgp
|
||||
# time ./mgmt run --lang examples/lang/exchange0.mcl --hostname h4 --seeds http://127.0.0.1:2379 --client-urls http://127.0.0.1:2385 --server-urls http://127.0.0.1:2386 --tmp-prefix --no-pgp
|
||||
|
||||
$rand = random1(8)
|
||||
$exchanged = exchange("keyns", $rand)
|
||||
|
||||
file "/tmp/mgmt/exchange-${hostname()}" {
|
||||
content => template("Found: {{ . }}\n", $exchanged),
|
||||
}
|
||||
4
examples/lang/hello0.mcl
Normal file
4
examples/lang/hello0.mcl
Normal file
@@ -0,0 +1,4 @@
|
||||
file "/tmp/mgmt-hello-world" {
|
||||
content => "hello world from @purpleidea\n",
|
||||
state => "exists",
|
||||
}
|
||||
7
examples/lang/history1.mcl
Normal file
7
examples/lang/history1.mcl
Normal file
@@ -0,0 +1,7 @@
|
||||
$dt = datetime()
|
||||
|
||||
$hystvalues = {"ix0" => $dt, "ix1" => $dt{1}, "ix2" => $dt{2}, "ix3" => $dt{3},}
|
||||
|
||||
file "/tmp/mgmt/history" {
|
||||
content => template("Index(0) {{.ix0}}: {{ datetimeprint .ix0 }}\nIndex(1) {{.ix1}}: {{ datetimeprint .ix1 }}\nIndex(2) {{.ix2}}: {{ datetimeprint .ix2 }}\nIndex(3) {{.ix3}}: {{ datetimeprint .ix3 }}\n", $hystvalues),
|
||||
}
|
||||
4
examples/lang/hostname0.mcl
Normal file
4
examples/lang/hostname0.mcl
Normal file
@@ -0,0 +1,4 @@
|
||||
file "/tmp/mgmt/${hostname()}" {
|
||||
content => "hello from ${hostname()}!\n",
|
||||
state => "exists",
|
||||
}
|
||||
31
examples/lang/hysteresis1.mcl
Normal file
31
examples/lang/hysteresis1.mcl
Normal file
@@ -0,0 +1,31 @@
|
||||
file "/tmp/mgmt/systemload" {
|
||||
content => template("load average: {{ .load }} threshold: {{ .threshold }}\n", $tmplvalues),
|
||||
}
|
||||
|
||||
$tmplvalues = struct{load => $theload, threshold => $threshold,}
|
||||
|
||||
$theload = structlookup(load(), "x1")
|
||||
$threshold = 1.5 # change me if you like
|
||||
|
||||
# simple hysteresis implementation
|
||||
$h1 = $theload > $threshold
|
||||
$h2 = $theload{1} > $threshold
|
||||
$h3 = $theload{2} > $threshold
|
||||
$unload = $h1 || $h2 || $h3
|
||||
|
||||
virt "mgmt1" {
|
||||
uri => "qemu:///session",
|
||||
cpus => 1,
|
||||
memory => 524288,
|
||||
state => "running",
|
||||
transient => true,
|
||||
}
|
||||
|
||||
# this vm shuts down under load...
|
||||
virt "mgmt2" {
|
||||
uri => "qemu:///session",
|
||||
cpus => 1,
|
||||
memory => 524288,
|
||||
state => if $unload { "shutoff" } else { "running" },
|
||||
transient => true,
|
||||
}
|
||||
5
examples/lang/interpolate1.mcl
Normal file
5
examples/lang/interpolate1.mcl
Normal file
@@ -0,0 +1,5 @@
|
||||
$audience = "WORLD!"
|
||||
file "/tmp/mgmt/hello" {
|
||||
content => "hello ${audience}!\n",
|
||||
state => "exists",
|
||||
}
|
||||
9
examples/lang/load0.mcl
Normal file
9
examples/lang/load0.mcl
Normal file
@@ -0,0 +1,9 @@
|
||||
$theload = load()
|
||||
|
||||
$x1 = structlookup($theload, "x1")
|
||||
$x5 = structlookup($theload, "x5")
|
||||
$x15 = structlookup($theload, "x15")
|
||||
|
||||
print "print1" {
|
||||
msg => printf("load average: %f, %f, %f", $x1, $x5, $x15),
|
||||
}
|
||||
13
examples/lang/maplookup1.mcl
Normal file
13
examples/lang/maplookup1.mcl
Normal file
@@ -0,0 +1,13 @@
|
||||
$m = {"k1" => 42, "k2" => 13,}
|
||||
|
||||
$found = maplookup($m, "k1", 99)
|
||||
|
||||
print "print1" {
|
||||
msg => printf("found value of: %d", $found),
|
||||
}
|
||||
|
||||
$notfound = maplookup($m, "k3", 99)
|
||||
|
||||
print "print2" {
|
||||
msg => printf("notfound value of: %d", $notfound),
|
||||
}
|
||||
4
examples/lang/math1.mcl
Normal file
4
examples/lang/math1.mcl
Normal file
@@ -0,0 +1,4 @@
|
||||
test "t1" {
|
||||
int64 => (4 + 32) * 15 - 8,
|
||||
anotherstr => printf("the answer is: %d", 42),
|
||||
}
|
||||
8
examples/lang/printf1.mcl
Normal file
8
examples/lang/printf1.mcl
Normal file
@@ -0,0 +1,8 @@
|
||||
test "printf-a" {
|
||||
anotherstr => printf("the %s is: %d", "answer", 42),
|
||||
}
|
||||
|
||||
$format = "a %s is: %f"
|
||||
test "printf-b" {
|
||||
anotherstr => printf($format, "cool number", 3.14159),
|
||||
}
|
||||
18
examples/lang/schedule0.mcl
Normal file
18
examples/lang/schedule0.mcl
Normal file
@@ -0,0 +1,18 @@
|
||||
# here are all the possible options:
|
||||
#$opts = struct{strategy => "rr", max => 3, reuse => false, ttl => 10,}
|
||||
|
||||
# although an empty struct is valid too:
|
||||
#$opts = struct{}
|
||||
|
||||
# we'll just use a smaller subset today:
|
||||
$opts = struct{strategy => "rr", max => 2, ttl => 10,}
|
||||
|
||||
# schedule in a particular namespace with options:
|
||||
$set = schedule("xsched", $opts)
|
||||
|
||||
# and if you want, you can omit the options entirely:
|
||||
#$set = schedule("xsched")
|
||||
|
||||
file "/tmp/mgmt/scheduled-${hostname()}" {
|
||||
content => template("set: {{ . }}\n", $set),
|
||||
}
|
||||
10
examples/lang/shadowing1.mcl
Normal file
10
examples/lang/shadowing1.mcl
Normal file
@@ -0,0 +1,10 @@
|
||||
$x = "hello"
|
||||
if true {
|
||||
$x = "i am shadowed" # this is allowed, but not a good practice to intentionally shadow
|
||||
print "inner-scope" {
|
||||
msg => $x, # contents are: i am shadowed
|
||||
}
|
||||
}
|
||||
print "top-scope" {
|
||||
msg => $x, # contents are: hello
|
||||
}
|
||||
35
examples/lang/states0.mcl
Normal file
35
examples/lang/states0.mcl
Normal file
@@ -0,0 +1,35 @@
|
||||
$ns = "estate"
|
||||
$exchanged = kvlookup($ns)
|
||||
|
||||
$state = maplookup($exchanged, $hostname, "default")
|
||||
|
||||
if $state == "one" || $state == "default" {
|
||||
|
||||
file "/tmp/mgmt/state" {
|
||||
content => "state: one\n",
|
||||
}
|
||||
kv "${ns}" {
|
||||
key => $ns,
|
||||
value => "two",
|
||||
}
|
||||
}
|
||||
if $state == "two" {
|
||||
|
||||
file "/tmp/mgmt/state" {
|
||||
content => "state: two\n",
|
||||
}
|
||||
kv "${ns}" {
|
||||
key => $ns,
|
||||
value => "three",
|
||||
}
|
||||
}
|
||||
if $state == "three" {
|
||||
|
||||
file "/tmp/mgmt/state" {
|
||||
content => "state: three\n",
|
||||
}
|
||||
kv "${ns}" {
|
||||
key => $ns,
|
||||
value => "one",
|
||||
}
|
||||
}
|
||||
13
examples/lang/structlookup1.mcl
Normal file
13
examples/lang/structlookup1.mcl
Normal file
@@ -0,0 +1,13 @@
|
||||
$st = struct{f1 => 42, f2 => true, f3 => 3.14,}
|
||||
|
||||
$f1 = structlookup($st, "f1")
|
||||
|
||||
print "print1" {
|
||||
msg => printf("f1 field is: %d", $f1),
|
||||
}
|
||||
|
||||
$f2 = structlookup($st, "f2")
|
||||
|
||||
print "print2" {
|
||||
msg => printf("f2 field is: %t", $f2),
|
||||
}
|
||||
7
examples/lang/virt1.mcl
Normal file
7
examples/lang/virt1.mcl
Normal file
@@ -0,0 +1,7 @@
|
||||
virt "mgmt3" {
|
||||
uri => "qemu:///session",
|
||||
cpus => 1,
|
||||
memory => 524288,
|
||||
state => "running",
|
||||
transient => true,
|
||||
}
|
||||
@@ -14,6 +14,15 @@ import (
|
||||
mgmt "github.com/purpleidea/mgmt/lib"
|
||||
"github.com/purpleidea/mgmt/pgraph"
|
||||
"github.com/purpleidea/mgmt/resources"
|
||||
|
||||
"github.com/urfave/cli"
|
||||
)
|
||||
|
||||
// XXX: this has not been updated to latest GAPI/Deploy API. Patches welcome!
|
||||
|
||||
const (
|
||||
// Name is the name of this frontend.
|
||||
Name = "libmgmt"
|
||||
)
|
||||
|
||||
// MyGAPI implements the main GAPI interface.
|
||||
@@ -36,6 +45,39 @@ func NewMyGAPI(data gapi.Data, name string, interval uint) (*MyGAPI, error) {
|
||||
return obj, obj.Init(data)
|
||||
}
|
||||
|
||||
// Cli takes a cli.Context, and returns our GAPI if activated. All arguments
|
||||
// should take the prefix of the registered name. On activation, if there are
|
||||
// any validation problems, you should return an error. If this was not
|
||||
// activated, then you should return a nil GAPI and a nil error.
|
||||
func (obj *MyGAPI) Cli(c *cli.Context, fs resources.Fs) (*gapi.Deploy, error) {
|
||||
if s := c.String(obj.Name); c.IsSet(obj.Name) {
|
||||
if s != "" {
|
||||
return nil, fmt.Errorf("input is not empty")
|
||||
}
|
||||
|
||||
return &gapi.Deploy{
|
||||
Name: obj.Name,
|
||||
Noop: c.GlobalBool("noop"),
|
||||
Sema: c.GlobalInt("sema"),
|
||||
GAPI: &MyGAPI{
|
||||
// TODO: add properties here...
|
||||
},
|
||||
}, nil
|
||||
}
|
||||
return nil, nil // we weren't activated!
|
||||
}
|
||||
|
||||
// CliFlags returns a list of flags used by this deploy subcommand.
|
||||
func (obj *MyGAPI) CliFlags() []cli.Flag {
|
||||
return []cli.Flag{
|
||||
cli.StringFlag{
|
||||
Name: obj.Name,
|
||||
Value: "",
|
||||
Usage: "run",
|
||||
},
|
||||
}
|
||||
}
|
||||
|
||||
// Init initializes the MyGAPI struct.
|
||||
func (obj *MyGAPI) Init(data gapi.Data) error {
|
||||
if obj.initialized {
|
||||
@@ -53,7 +95,7 @@ func (obj *MyGAPI) Init(data gapi.Data) error {
|
||||
// Graph returns a current Graph.
|
||||
func (obj *MyGAPI) Graph() (*pgraph.Graph, error) {
|
||||
if !obj.initialized {
|
||||
return nil, fmt.Errorf("libmgmt: MyGAPI is not initialized")
|
||||
return nil, fmt.Errorf("%s: MyGAPI is not initialized", Name)
|
||||
}
|
||||
|
||||
g, err := pgraph.NewGraph(obj.Name)
|
||||
@@ -135,7 +177,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
defer close(ch) // this will run before the obj.wg.Done()
|
||||
if !obj.initialized {
|
||||
next := gapi.Next{
|
||||
Err: fmt.Errorf("libmgmt: MyGAPI is not initialized"),
|
||||
Err: fmt.Errorf("%s: MyGAPI is not initialized", Name),
|
||||
Exit: true, // exit, b/c programming error?
|
||||
}
|
||||
ch <- next
|
||||
@@ -164,7 +206,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
return
|
||||
}
|
||||
|
||||
log.Printf("libmgmt: Generating new graph...")
|
||||
log.Printf("%s: Generating new graph...", Name)
|
||||
select {
|
||||
case ch <- gapi.Next{}: // trigger a run
|
||||
case <-obj.closeChan:
|
||||
@@ -178,7 +220,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
// Close shuts down the MyGAPI.
|
||||
func (obj *MyGAPI) Close() error {
|
||||
if !obj.initialized {
|
||||
return fmt.Errorf("libmgmt: MyGAPI is not initialized")
|
||||
return fmt.Errorf("%s: MyGAPI is not initialized", Name)
|
||||
}
|
||||
close(obj.closeChan)
|
||||
obj.wg.Wait()
|
||||
@@ -199,10 +241,10 @@ func Run() error {
|
||||
obj.ConvergedTimeout = -1
|
||||
obj.Noop = false // FIXME: careful!
|
||||
|
||||
obj.GAPI = &MyGAPI{ // graph API
|
||||
Name: "libmgmt", // TODO: set on compilation
|
||||
Interval: 60 * 10, // arbitrarily change graph every 15 seconds
|
||||
}
|
||||
//obj.GAPI = &MyGAPI{ // graph API
|
||||
// Name: "libmgmt", // TODO: set on compilation
|
||||
// Interval: 60 * 10, // arbitrarily change graph every 15 seconds
|
||||
//}
|
||||
|
||||
if err := obj.Init(); err != nil {
|
||||
return err
|
||||
|
||||
@@ -16,8 +16,20 @@ import (
|
||||
"github.com/purpleidea/mgmt/resources"
|
||||
|
||||
errwrap "github.com/pkg/errors"
|
||||
"github.com/urfave/cli"
|
||||
)
|
||||
|
||||
// XXX: this has not been updated to latest GAPI/Deploy API. Patches welcome!
|
||||
|
||||
const (
|
||||
// Name is the name of this frontend.
|
||||
Name = "libmgmt"
|
||||
)
|
||||
|
||||
func init() {
|
||||
gapi.Register(Name, func() gapi.GAPI { return &MyGAPI{} }) // register
|
||||
}
|
||||
|
||||
// MyGAPI implements the main GAPI interface.
|
||||
type MyGAPI struct {
|
||||
Name string // graph name
|
||||
@@ -38,6 +50,39 @@ func NewMyGAPI(data gapi.Data, name string, interval uint) (*MyGAPI, error) {
|
||||
return obj, obj.Init(data)
|
||||
}
|
||||
|
||||
// Cli takes a cli.Context, and returns our GAPI if activated. All arguments
|
||||
// should take the prefix of the registered name. On activation, if there are
|
||||
// any validation problems, you should return an error. If this was not
|
||||
// activated, then you should return a nil GAPI and a nil error.
|
||||
func (obj *MyGAPI) Cli(c *cli.Context, fs resources.Fs) (*gapi.Deploy, error) {
|
||||
if s := c.String(obj.Name); c.IsSet(obj.Name) {
|
||||
if s != "" {
|
||||
return nil, fmt.Errorf("input is not empty")
|
||||
}
|
||||
|
||||
return &gapi.Deploy{
|
||||
Name: obj.Name,
|
||||
Noop: c.GlobalBool("noop"),
|
||||
Sema: c.GlobalInt("sema"),
|
||||
GAPI: &MyGAPI{
|
||||
// TODO: add properties here...
|
||||
},
|
||||
}, nil
|
||||
}
|
||||
return nil, nil // we weren't activated!
|
||||
}
|
||||
|
||||
// CliFlags returns a list of flags used by this deploy subcommand.
|
||||
func (obj *MyGAPI) CliFlags() []cli.Flag {
|
||||
return []cli.Flag{
|
||||
cli.StringFlag{
|
||||
Name: obj.Name,
|
||||
Value: "",
|
||||
Usage: "run",
|
||||
},
|
||||
}
|
||||
}
|
||||
|
||||
// Init initializes the MyGAPI struct.
|
||||
func (obj *MyGAPI) Init(data gapi.Data) error {
|
||||
if obj.initialized {
|
||||
@@ -87,7 +132,7 @@ func (obj *MyGAPI) subGraph() (*pgraph.Graph, error) {
|
||||
// Graph returns a current Graph.
|
||||
func (obj *MyGAPI) Graph() (*pgraph.Graph, error) {
|
||||
if !obj.initialized {
|
||||
return nil, fmt.Errorf("libmgmt: MyGAPI is not initialized")
|
||||
return nil, fmt.Errorf("%s: MyGAPI is not initialized", Name)
|
||||
}
|
||||
|
||||
g, err := pgraph.NewGraph(obj.Name)
|
||||
@@ -142,7 +187,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
defer close(ch) // this will run before the obj.wg.Done()
|
||||
if !obj.initialized {
|
||||
next := gapi.Next{
|
||||
Err: fmt.Errorf("libmgmt: MyGAPI is not initialized"),
|
||||
Err: fmt.Errorf("%s: MyGAPI is not initialized", Name),
|
||||
Exit: true, // exit, b/c programming error?
|
||||
}
|
||||
ch <- next
|
||||
@@ -171,7 +216,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
return
|
||||
}
|
||||
|
||||
log.Printf("libmgmt: Generating new graph...")
|
||||
log.Printf("%s: Generating new graph...", Name)
|
||||
select {
|
||||
case ch <- gapi.Next{}: // trigger a run
|
||||
case <-obj.closeChan:
|
||||
@@ -185,7 +230,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
// Close shuts down the MyGAPI.
|
||||
func (obj *MyGAPI) Close() error {
|
||||
if !obj.initialized {
|
||||
return fmt.Errorf("libmgmt: MyGAPI is not initialized")
|
||||
return fmt.Errorf("%s: MyGAPI is not initialized", Name)
|
||||
}
|
||||
close(obj.closeChan)
|
||||
obj.wg.Wait()
|
||||
@@ -197,19 +242,19 @@ func (obj *MyGAPI) Close() error {
|
||||
func Run() error {
|
||||
|
||||
obj := &mgmt.Main{}
|
||||
obj.Program = "libmgmt" // TODO: set on compilation
|
||||
obj.Version = "0.0.1" // TODO: set on compilation
|
||||
obj.TmpPrefix = true // disable for easy debugging
|
||||
obj.Program = Name // TODO: set on compilation
|
||||
obj.Version = "0.0.1" // TODO: set on compilation
|
||||
obj.TmpPrefix = true // disable for easy debugging
|
||||
//prefix := "/tmp/testprefix/"
|
||||
//obj.Prefix = &p // enable for easy debugging
|
||||
obj.IdealClusterSize = -1
|
||||
obj.ConvergedTimeout = -1
|
||||
obj.Noop = false // FIXME: careful!
|
||||
|
||||
obj.GAPI = &MyGAPI{ // graph API
|
||||
Name: "libmgmt", // TODO: set on compilation
|
||||
Interval: 60 * 10, // arbitrarily change graph every 15 seconds
|
||||
}
|
||||
//obj.GAPI = &MyGAPI{ // graph API
|
||||
// Name: Name, // TODO: set on compilation
|
||||
// Interval: 60 * 10, // arbitrarily change graph every 15 seconds
|
||||
//}
|
||||
|
||||
if err := obj.Init(); err != nil {
|
||||
return err
|
||||
|
||||
@@ -14,6 +14,15 @@ import (
|
||||
mgmt "github.com/purpleidea/mgmt/lib"
|
||||
"github.com/purpleidea/mgmt/pgraph"
|
||||
"github.com/purpleidea/mgmt/resources"
|
||||
|
||||
"github.com/urfave/cli"
|
||||
)
|
||||
|
||||
// XXX: this has not been updated to latest GAPI/Deploy API. Patches welcome!
|
||||
|
||||
const (
|
||||
// Name is the name of this frontend.
|
||||
Name = "libmgmt"
|
||||
)
|
||||
|
||||
// MyGAPI implements the main GAPI interface.
|
||||
@@ -36,6 +45,39 @@ func NewMyGAPI(data gapi.Data, name string, interval uint) (*MyGAPI, error) {
|
||||
return obj, obj.Init(data)
|
||||
}
|
||||
|
||||
// Cli takes a cli.Context, and returns our GAPI if activated. All arguments
|
||||
// should take the prefix of the registered name. On activation, if there are
|
||||
// any validation problems, you should return an error. If this was not
|
||||
// activated, then you should return a nil GAPI and a nil error.
|
||||
func (obj *MyGAPI) Cli(c *cli.Context, fs resources.Fs) (*gapi.Deploy, error) {
|
||||
if s := c.String(obj.Name); c.IsSet(obj.Name) {
|
||||
if s != "" {
|
||||
return nil, fmt.Errorf("input is not empty")
|
||||
}
|
||||
|
||||
return &gapi.Deploy{
|
||||
Name: obj.Name,
|
||||
Noop: c.GlobalBool("noop"),
|
||||
Sema: c.GlobalInt("sema"),
|
||||
GAPI: &MyGAPI{
|
||||
// TODO: add properties here...
|
||||
},
|
||||
}, nil
|
||||
}
|
||||
return nil, nil // we weren't activated!
|
||||
}
|
||||
|
||||
// CliFlags returns a list of flags used by this deploy subcommand.
|
||||
func (obj *MyGAPI) CliFlags() []cli.Flag {
|
||||
return []cli.Flag{
|
||||
cli.StringFlag{
|
||||
Name: obj.Name,
|
||||
Value: "",
|
||||
Usage: "run",
|
||||
},
|
||||
}
|
||||
}
|
||||
|
||||
// Init initializes the MyGAPI struct.
|
||||
func (obj *MyGAPI) Init(data gapi.Data) error {
|
||||
if obj.initialized {
|
||||
@@ -53,7 +95,7 @@ func (obj *MyGAPI) Init(data gapi.Data) error {
|
||||
// Graph returns a current Graph.
|
||||
func (obj *MyGAPI) Graph() (*pgraph.Graph, error) {
|
||||
if !obj.initialized {
|
||||
return nil, fmt.Errorf("libmgmt: MyGAPI is not initialized")
|
||||
return nil, fmt.Errorf("%s: MyGAPI is not initialized", Name)
|
||||
}
|
||||
|
||||
g, err := pgraph.NewGraph(obj.Name)
|
||||
@@ -132,7 +174,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
defer close(ch) // this will run before the obj.wg.Done()
|
||||
if !obj.initialized {
|
||||
next := gapi.Next{
|
||||
Err: fmt.Errorf("libmgmt: MyGAPI is not initialized"),
|
||||
Err: fmt.Errorf("%s: MyGAPI is not initialized", Name),
|
||||
Exit: true, // exit, b/c programming error?
|
||||
}
|
||||
ch <- next
|
||||
@@ -161,7 +203,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
return
|
||||
}
|
||||
|
||||
log.Printf("libmgmt: Generating new graph...")
|
||||
log.Printf("%s: Generating new graph...", Name)
|
||||
select {
|
||||
case ch <- gapi.Next{}: // trigger a run
|
||||
case <-obj.closeChan:
|
||||
@@ -175,7 +217,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
// Close shuts down the MyGAPI.
|
||||
func (obj *MyGAPI) Close() error {
|
||||
if !obj.initialized {
|
||||
return fmt.Errorf("libmgmt: MyGAPI is not initialized")
|
||||
return fmt.Errorf("%s: MyGAPI is not initialized", Name)
|
||||
}
|
||||
close(obj.closeChan)
|
||||
obj.wg.Wait()
|
||||
@@ -196,10 +238,10 @@ func Run() error {
|
||||
obj.ConvergedTimeout = -1
|
||||
obj.Noop = false // FIXME: careful!
|
||||
|
||||
obj.GAPI = &MyGAPI{ // graph API
|
||||
Name: "libmgmt", // TODO: set on compilation
|
||||
Interval: 60 * 10, // arbitrarily change graph every 15 seconds
|
||||
}
|
||||
//obj.GAPI = &MyGAPI{ // graph API
|
||||
// Name: "libmgmt", // TODO: set on compilation
|
||||
// Interval: 60 * 10, // arbitrarily change graph every 15 seconds
|
||||
//}
|
||||
|
||||
if err := obj.Init(); err != nil {
|
||||
return err
|
||||
|
||||
@@ -15,6 +15,15 @@ import (
|
||||
"github.com/purpleidea/mgmt/pgraph"
|
||||
"github.com/purpleidea/mgmt/resources"
|
||||
"github.com/purpleidea/mgmt/yamlgraph"
|
||||
|
||||
"github.com/urfave/cli"
|
||||
)
|
||||
|
||||
// XXX: this has not been updated to latest GAPI/Deploy API. Patches welcome!
|
||||
|
||||
const (
|
||||
// Name is the name of this frontend.
|
||||
Name = "libmgmt"
|
||||
)
|
||||
|
||||
// MyGAPI implements the main GAPI interface.
|
||||
@@ -37,6 +46,39 @@ func NewMyGAPI(data gapi.Data, name string, interval uint) (*MyGAPI, error) {
|
||||
return obj, obj.Init(data)
|
||||
}
|
||||
|
||||
// Cli takes a cli.Context, and returns our GAPI if activated. All arguments
|
||||
// should take the prefix of the registered name. On activation, if there are
|
||||
// any validation problems, you should return an error. If this was not
|
||||
// activated, then you should return a nil GAPI and a nil error.
|
||||
func (obj *MyGAPI) Cli(c *cli.Context, fs resources.Fs) (*gapi.Deploy, error) {
|
||||
if s := c.String(obj.Name); c.IsSet(obj.Name) {
|
||||
if s != "" {
|
||||
return nil, fmt.Errorf("input is not empty")
|
||||
}
|
||||
|
||||
return &gapi.Deploy{
|
||||
Name: obj.Name,
|
||||
Noop: c.GlobalBool("noop"),
|
||||
Sema: c.GlobalInt("sema"),
|
||||
GAPI: &MyGAPI{
|
||||
// TODO: add properties here...
|
||||
},
|
||||
}, nil
|
||||
}
|
||||
return nil, nil // we weren't activated!
|
||||
}
|
||||
|
||||
// CliFlags returns a list of flags used by this deploy subcommand.
|
||||
func (obj *MyGAPI) CliFlags() []cli.Flag {
|
||||
return []cli.Flag{
|
||||
cli.StringFlag{
|
||||
Name: obj.Name,
|
||||
Value: "",
|
||||
Usage: "run",
|
||||
},
|
||||
}
|
||||
}
|
||||
|
||||
// Init initializes the MyGAPI struct.
|
||||
func (obj *MyGAPI) Init(data gapi.Data) error {
|
||||
if obj.initialized {
|
||||
@@ -54,7 +96,7 @@ func (obj *MyGAPI) Init(data gapi.Data) error {
|
||||
// Graph returns a current Graph.
|
||||
func (obj *MyGAPI) Graph() (*pgraph.Graph, error) {
|
||||
if !obj.initialized {
|
||||
return nil, fmt.Errorf("libmgmt: MyGAPI is not initialized")
|
||||
return nil, fmt.Errorf("%s: MyGAPI is not initialized", Name)
|
||||
}
|
||||
|
||||
n1, err := resources.NewNamedResource("noop", "noop1")
|
||||
@@ -96,7 +138,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
defer close(ch) // this will run before the obj.wg.Done()
|
||||
if !obj.initialized {
|
||||
next := gapi.Next{
|
||||
Err: fmt.Errorf("libmgmt: MyGAPI is not initialized"),
|
||||
Err: fmt.Errorf("%s: MyGAPI is not initialized", Name),
|
||||
Exit: true, // exit, b/c programming error?
|
||||
}
|
||||
ch <- next
|
||||
@@ -124,7 +166,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
return
|
||||
}
|
||||
|
||||
log.Printf("libmgmt: Generating new graph...")
|
||||
log.Printf("%s: Generating new graph...", Name)
|
||||
select {
|
||||
case ch <- gapi.Next{}: // trigger a run
|
||||
case <-obj.closeChan:
|
||||
@@ -138,7 +180,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
// Close shuts down the MyGAPI.
|
||||
func (obj *MyGAPI) Close() error {
|
||||
if !obj.initialized {
|
||||
return fmt.Errorf("libmgmt: MyGAPI is not initialized")
|
||||
return fmt.Errorf("%s: MyGAPI is not initialized", Name)
|
||||
}
|
||||
close(obj.closeChan)
|
||||
obj.wg.Wait()
|
||||
@@ -157,10 +199,10 @@ func Run() error {
|
||||
obj.ConvergedTimeout = -1
|
||||
obj.Noop = true
|
||||
|
||||
obj.GAPI = &MyGAPI{ // graph API
|
||||
Name: "libmgmt", // TODO: set on compilation
|
||||
Interval: 15, // arbitrarily change graph every 15 seconds
|
||||
}
|
||||
//obj.GAPI = &MyGAPI{ // graph API
|
||||
// Name: "libmgmt", // TODO: set on compilation
|
||||
// Interval: 15, // arbitrarily change graph every 15 seconds
|
||||
//}
|
||||
|
||||
if err := obj.Init(); err != nil {
|
||||
return err
|
||||
|
||||
@@ -15,6 +15,15 @@ import (
|
||||
mgmt "github.com/purpleidea/mgmt/lib"
|
||||
"github.com/purpleidea/mgmt/pgraph"
|
||||
"github.com/purpleidea/mgmt/resources"
|
||||
|
||||
"github.com/urfave/cli"
|
||||
)
|
||||
|
||||
// XXX: this has not been updated to latest GAPI/Deploy API. Patches welcome!
|
||||
|
||||
const (
|
||||
// Name is the name of this frontend.
|
||||
Name = "libmgmt"
|
||||
)
|
||||
|
||||
// MyGAPI implements the main GAPI interface.
|
||||
@@ -39,6 +48,39 @@ func NewMyGAPI(data gapi.Data, name string, interval uint, count uint) (*MyGAPI,
|
||||
return obj, obj.Init(data)
|
||||
}
|
||||
|
||||
// Cli takes a cli.Context, and returns our GAPI if activated. All arguments
|
||||
// should take the prefix of the registered name. On activation, if there are
|
||||
// any validation problems, you should return an error. If this was not
|
||||
// activated, then you should return a nil GAPI and a nil error.
|
||||
func (obj *MyGAPI) Cli(c *cli.Context, fs resources.Fs) (*gapi.Deploy, error) {
|
||||
if s := c.String(obj.Name); c.IsSet(obj.Name) {
|
||||
if s != "" {
|
||||
return nil, fmt.Errorf("input is not empty")
|
||||
}
|
||||
|
||||
return &gapi.Deploy{
|
||||
Name: obj.Name,
|
||||
Noop: c.GlobalBool("noop"),
|
||||
Sema: c.GlobalInt("sema"),
|
||||
GAPI: &MyGAPI{
|
||||
// TODO: add properties here...
|
||||
},
|
||||
}, nil
|
||||
}
|
||||
return nil, nil // we weren't activated!
|
||||
}
|
||||
|
||||
// CliFlags returns a list of flags used by this deploy subcommand.
|
||||
func (obj *MyGAPI) CliFlags() []cli.Flag {
|
||||
return []cli.Flag{
|
||||
cli.StringFlag{
|
||||
Name: obj.Name,
|
||||
Value: "",
|
||||
Usage: "run",
|
||||
},
|
||||
}
|
||||
}
|
||||
|
||||
// Init initializes the MyGAPI struct.
|
||||
func (obj *MyGAPI) Init(data gapi.Data) error {
|
||||
if obj.initialized {
|
||||
@@ -56,7 +98,7 @@ func (obj *MyGAPI) Init(data gapi.Data) error {
|
||||
// Graph returns a current Graph.
|
||||
func (obj *MyGAPI) Graph() (*pgraph.Graph, error) {
|
||||
if !obj.initialized {
|
||||
return nil, fmt.Errorf("libmgmt: MyGAPI is not initialized")
|
||||
return nil, fmt.Errorf("%s: MyGAPI is not initialized", Name)
|
||||
}
|
||||
|
||||
g, err := pgraph.NewGraph(obj.Name)
|
||||
@@ -89,7 +131,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
defer close(ch) // this will run before the obj.wg.Done()
|
||||
if !obj.initialized {
|
||||
next := gapi.Next{
|
||||
Err: fmt.Errorf("libmgmt: MyGAPI is not initialized"),
|
||||
Err: fmt.Errorf("%s: MyGAPI is not initialized", Name),
|
||||
Exit: true, // exit, b/c programming error?
|
||||
}
|
||||
ch <- next
|
||||
@@ -117,7 +159,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
return
|
||||
}
|
||||
|
||||
log.Printf("libmgmt: Generating new graph...")
|
||||
log.Printf("%s: Generating new graph...", Name)
|
||||
select {
|
||||
case ch <- gapi.Next{}: // trigger a run
|
||||
case <-obj.closeChan:
|
||||
@@ -131,7 +173,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
// Close shuts down the MyGAPI.
|
||||
func (obj *MyGAPI) Close() error {
|
||||
if !obj.initialized {
|
||||
return fmt.Errorf("libmgmt: MyGAPI is not initialized")
|
||||
return fmt.Errorf("%s: MyGAPI is not initialized", Name)
|
||||
}
|
||||
close(obj.closeChan)
|
||||
obj.wg.Wait()
|
||||
@@ -150,11 +192,11 @@ func Run(count uint) error {
|
||||
obj.ConvergedTimeout = -1
|
||||
obj.Noop = true
|
||||
|
||||
obj.GAPI = &MyGAPI{ // graph API
|
||||
Name: "libmgmt", // TODO: set on compilation
|
||||
Count: count, // number of vertices to add
|
||||
Interval: 15, // arbitrarily change graph every 15 seconds
|
||||
}
|
||||
//obj.GAPI = &MyGAPI{ // graph API
|
||||
// Name: "libmgmt", // TODO: set on compilation
|
||||
// Count: count, // number of vertices to add
|
||||
// Interval: 15, // arbitrarily change graph every 15 seconds
|
||||
//}
|
||||
|
||||
if err := obj.Init(); err != nil {
|
||||
return err
|
||||
|
||||
@@ -14,6 +14,15 @@ import (
|
||||
mgmt "github.com/purpleidea/mgmt/lib"
|
||||
"github.com/purpleidea/mgmt/pgraph"
|
||||
"github.com/purpleidea/mgmt/resources"
|
||||
|
||||
"github.com/urfave/cli"
|
||||
)
|
||||
|
||||
// XXX: this has not been updated to latest GAPI/Deploy API. Patches welcome!
|
||||
|
||||
const (
|
||||
// Name is the name of this frontend.
|
||||
Name = "libmgmt"
|
||||
)
|
||||
|
||||
// MyGAPI implements the main GAPI interface.
|
||||
@@ -36,6 +45,39 @@ func NewMyGAPI(data gapi.Data, name string, interval uint) (*MyGAPI, error) {
|
||||
return obj, obj.Init(data)
|
||||
}
|
||||
|
||||
// Cli takes a cli.Context, and returns our GAPI if activated. All arguments
|
||||
// should take the prefix of the registered name. On activation, if there are
|
||||
// any validation problems, you should return an error. If this was not
|
||||
// activated, then you should return a nil GAPI and a nil error.
|
||||
func (obj *MyGAPI) Cli(c *cli.Context, fs resources.Fs) (*gapi.Deploy, error) {
|
||||
if s := c.String(obj.Name); c.IsSet(obj.Name) {
|
||||
if s != "" {
|
||||
return nil, fmt.Errorf("input is not empty")
|
||||
}
|
||||
|
||||
return &gapi.Deploy{
|
||||
Name: obj.Name,
|
||||
Noop: c.GlobalBool("noop"),
|
||||
Sema: c.GlobalInt("sema"),
|
||||
GAPI: &MyGAPI{
|
||||
// TODO: add properties here...
|
||||
},
|
||||
}, nil
|
||||
}
|
||||
return nil, nil // we weren't activated!
|
||||
}
|
||||
|
||||
// CliFlags returns a list of flags used by this deploy subcommand.
|
||||
func (obj *MyGAPI) CliFlags() []cli.Flag {
|
||||
return []cli.Flag{
|
||||
cli.StringFlag{
|
||||
Name: obj.Name,
|
||||
Value: "",
|
||||
Usage: "run",
|
||||
},
|
||||
}
|
||||
}
|
||||
|
||||
// Init initializes the MyGAPI struct.
|
||||
func (obj *MyGAPI) Init(data gapi.Data) error {
|
||||
if obj.initialized {
|
||||
@@ -53,7 +95,7 @@ func (obj *MyGAPI) Init(data gapi.Data) error {
|
||||
// Graph returns a current Graph.
|
||||
func (obj *MyGAPI) Graph() (*pgraph.Graph, error) {
|
||||
if !obj.initialized {
|
||||
return nil, fmt.Errorf("libmgmt: MyGAPI is not initialized")
|
||||
return nil, fmt.Errorf("%s: MyGAPI is not initialized", Name)
|
||||
}
|
||||
|
||||
g, err := pgraph.NewGraph(obj.Name)
|
||||
@@ -138,7 +180,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
defer close(ch) // this will run before the obj.wg.Done()
|
||||
if !obj.initialized {
|
||||
next := gapi.Next{
|
||||
Err: fmt.Errorf("libmgmt: MyGAPI is not initialized"),
|
||||
Err: fmt.Errorf("%s: MyGAPI is not initialized", Name),
|
||||
Exit: true, // exit, b/c programming error?
|
||||
}
|
||||
ch <- next
|
||||
@@ -166,7 +208,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
return
|
||||
}
|
||||
|
||||
log.Printf("libmgmt: Generating new graph...")
|
||||
log.Printf("%s: Generating new graph...", Name)
|
||||
select {
|
||||
case ch <- gapi.Next{}: // trigger a run
|
||||
case <-obj.closeChan:
|
||||
@@ -180,7 +222,7 @@ func (obj *MyGAPI) Next() chan gapi.Next {
|
||||
// Close shuts down the MyGAPI.
|
||||
func (obj *MyGAPI) Close() error {
|
||||
if !obj.initialized {
|
||||
return fmt.Errorf("libmgmt: MyGAPI is not initialized")
|
||||
return fmt.Errorf("%s: MyGAPI is not initialized", Name)
|
||||
}
|
||||
close(obj.closeChan)
|
||||
obj.wg.Wait()
|
||||
@@ -201,10 +243,10 @@ func Run() error {
|
||||
obj.ConvergedTimeout = -1
|
||||
obj.Noop = false // FIXME: careful!
|
||||
|
||||
obj.GAPI = &MyGAPI{ // graph API
|
||||
Name: "libmgmt", // TODO: set on compilation
|
||||
Interval: 60 * 10, // arbitrarily change graph every 15 seconds
|
||||
}
|
||||
//obj.GAPI = &MyGAPI{ // graph API
|
||||
// Name: "libmgmt", // TODO: set on compilation
|
||||
// Interval: 60 * 10, // arbitrarily change graph every 15 seconds
|
||||
//}
|
||||
|
||||
if err := obj.Init(); err != nil {
|
||||
return err
|
||||
|
||||
Some files were not shown because too many files have changed in this diff Show More
Reference in New Issue
Block a user