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.

gapi/deploy.go

@@ -0,0 +1,68 @@
+// 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 gapi
+
+import (
+	"bytes"
+	"encoding/base64"
+	"encoding/gob"
+
+	errwrap "github.com/pkg/errors"
+)
+
+func init() {
+	gob.Register(&Deploy{})
+}
+
+// Deploy represents a deploy action, include the type of GAPI to deploy, the
+// payload of that GAPI, and any deploy specific parameters that were chosen.
+// TODO: add staged rollout functionality to this struct
+// TODO: add proper authentication with gpg key signing
+type Deploy struct {
+	Name string // lang, hcl, puppet, yaml, yaml2, etc...
+	//Sync bool // wait for everyone to close previous GAPI before switching
+	Noop bool
+	Sema int // sema override
+	GAPI GAPI
+}
+
+// ToB64 encodes a deploy struct as a base64 encoded string.
+func (obj *Deploy) ToB64() (string, error) {
+	b := bytes.Buffer{}
+	e := gob.NewEncoder(&b)
+	err := e.Encode(&obj) // pass with &
+	if err != nil {
+		return "", errwrap.Wrapf(err, "gob failed to encode")
+	}
+	return base64.StdEncoding.EncodeToString(b.Bytes()), nil
+}
+
+// NewDeployFromB64 decodes a deploy struct from a base64 encoded string.
+func NewDeployFromB64(str string) (*Deploy, error) {
+	var deploy *Deploy
+	bb, err := base64.StdEncoding.DecodeString(str)
+	if err != nil {
+		return nil, errwrap.Wrapf(err, "base64 failed to decode")
+	}
+	b := bytes.NewBuffer(bb)
+	d := gob.NewDecoder(b)
+	if err := d.Decode(&deploy); err != nil { // pass with &
+		return nil, errwrap.Wrapf(err, "gob failed to decode")
+	}
+	return deploy, nil
+}