Added Actions to charm.

charm/actions.go

+// Copyright 2011, 2012, 2013 Canonical Ltd.
+// Licensed under the AGPLv3, see LICENCE file for details.
+
+package charm
+
+import (
+        "fmt"
+        "io"
+        "io/ioutil"
+        "regexp"
+
+        "github.com/binary132/gojsonschema"
+        "launchpad.net/goyaml"
+)
+
+var nameRule = regexp.MustCompile("^[a-z](?:[a-z-]*[a-z])?$")
+
+// Actions defines the available actions for the charm.
+type Actions struct {
+        ActionSpecs map[string]ActionSpec `yaml:"actions"`
+}
+
+// ActionSpec is a definition of the parameters and traits of an Action.
+type ActionSpec struct {
+        Description string
+        Params      map[string]interface{}
+}
+
+// ReadActions builds an Actions spec from a charm's actions.yaml.
+func ReadActionsYaml(r io.Reader) (*Actions, error) {
+        data, err := ioutil.ReadAll(r)
+        if err != nil {
+                return nil, err
+        }
+        var unmarshaledActions Actions
+        if err := goyaml.Unmarshal(data, &unmarshaledActions); err != nil {
+                return nil, err
+        }
+
+        for name, actionSpec := range unmarshaledActions.ActionSpecs {
+                if valid := nameRule.MatchString(name); !valid {
+                        return nil, fmt.Errorf("bad action name %s", name)
+                }
+                _, err := gojsonschema.NewJsonSchemaDocument(actionSpec.Params)
+                if err != nil {
+                        return nil, fmt.Errorf("invalid params schema for action %q: %v", err)

[gz, 2014/05/29 15:17:04]

This error branch doesn't seem to be tested. The fmt.Errorf is invalid?

+                }
+                for paramName, _ := range unmarshaledActions.ActionSpecs[name].Params {
+                        if valid := nameRule.MatchString(paramName); !valid {
+                                return nil, fmt.Errorf("bad param name %s", paramName)
+                        }
+                }
+        }
+        return &unmarshaledActions, nil
+}