Merge pull request #141 from binary132/actions-uniter-api-watcher

Uniter API now has WatchActions

This commit adds state/api and state/apiserver endpoints for
WatchActions.

state/api/uniter/action.go

@@ -3,19 +3,23 @@
 
 package uniter
 
+// Action represents a single instance of an Action call, by name and params.
 type Action struct {
 	name   string
 	params map[string]interface{}
 }
 
+// NewAction makes a new Action with specified name and params map.
 func NewAction(name string, params map[string]interface{}) (*Action, error) {
 	return &Action{name: name, params: params}, nil
 }
 
+// Name retrieves the name of the Action.
 func (a *Action) Name() string {
 	return a.name
 }
 
+// Params retrieves the params map of the Action.
 func (a *Action) Params() map[string]interface{} {
 	return a.params
 }

state/api/uniter/export_test.go

@@ -3,3 +3,5 @@
 package uniter
 
 var NewSettings = newSettings
+
+var Call = &call

state/api/uniter/unit.go

@@ -437,6 +437,29 @@ func (u *Unit) WatchAddresses() (watcher.NotifyWatcher, error) {
 	return w, nil
 }
 
+// WatchActions returns a StringsWatcher for observing the ids of Actions
+// added to the Unit.  The initial event will contain the ids of any Actions
+// pending at the time the Watcher is made.
+func (u *Unit) WatchActions() (watcher.StringsWatcher, error) {
+	var results params.StringsWatchResults
+	args := params.Entities{
+		Entities: []params.Entity{{Tag: u.tag.String()}},
+	}
+	err := u.st.call("WatchActions", args, &results)
+	if err != nil {
+		return nil, err
+	}
+	if len(results.Results) != 1 {
+		return nil, fmt.Errorf("expected 1 result, got %d", len(results.Results))
+	}
+	result := results.Results[0]
+	if result.Error != nil {
+		return nil, result.Error
+	}
+	w := watcher.NewStringsWatcher(u.st.caller, result)
+	return w, nil
+}
+
 // JoinedRelations returns the tags of the relations the unit has joined.
 func (u *Unit) JoinedRelations() ([]string, error) {
 	var results params.StringsResults

state/api/uniter/unit_test.go

@@ -4,11 +4,13 @@
 package uniter_test
 
 import (
+	"fmt"
 	"sort"
 
 	"github.com/juju/charm"
 	"github.com/juju/errors"
 	"github.com/juju/names"
+	"github.com/juju/testing"
 	jc "github.com/juju/testing/checkers"
 	gc "launchpad.net/gocheck"
 
@@ -354,6 +356,93 @@ func (s *unitSuite) TestWatchConfigSettings(c *gc.C) {
 	wc.AssertClosed()
 }
 
+func (s *unitSuite) TestWatchActions(c *gc.C) {
+	w, err := s.apiUnit.WatchActions()
+	c.Assert(err, gc.IsNil)
+
+	defer statetesting.AssertStop(c, w)
+	wc := statetesting.NewStringsWatcherC(c, s.BackingState, w)
+
+	// Initial event.
+	wc.AssertChange()
+
+	// Add a couple of actions and make sure the changes are detected.
+	action, err := s.wordpressUnit.AddAction("snapshot", map[string]interface{}{
+		"outfile": "foo.txt",
+	})
+	c.Assert(err, gc.IsNil)
+	wc.AssertChange(action.Id())
+
+	action, err = s.wordpressUnit.AddAction("backup", map[string]interface{}{
+		"outfile": "foo.bz2",
+		"compression": map[string]interface{}{
+			"kind":    "bzip",
+			"quality": float64(5.0),
+		},
+	})
+	c.Assert(err, gc.IsNil)
+	wc.AssertChange(action.Id())
+
+	statetesting.AssertStop(c, w)
+	wc.AssertClosed()
+}
+
+func (s *unitSuite) TestWatchActionsError(c *gc.C) {
+	restore := testing.PatchValue(uniter.Call, func(st *uniter.State, method string, params, results interface{}) error {
+		return fmt.Errorf("Test error")
+	})
+
+	defer restore()
+
+	_, err := s.apiUnit.WatchActions()
+	c.Assert(err.Error(), gc.Equals, "Test error")
+}
+
+func (s *unitSuite) TestWatchActionsErrorResults(c *gc.C) {
+	restore := testing.PatchValue(uniter.Call, func(st *uniter.State, method string, args, results interface{}) error {
+		if results, ok := results.(*params.StringsWatchResults); ok {
+			results.Results = make([]params.StringsWatchResult, 1)
+			results.Results[0] = params.StringsWatchResult{
+				Error: &params.Error{
+					Message: "An error in the watch result.",
+					Code:    params.CodeNotAssigned,
+				},
+			}
+		}
+		return nil
+	})
+
+	defer restore()
+
+	_, err := s.apiUnit.WatchActions()
+	c.Assert(err.Error(), gc.Equals, "An error in the watch result.")
+}
+
+func (s *unitSuite) TestWatchActionsNoResults(c *gc.C) {
+	restore := testing.PatchValue(uniter.Call, func(st *uniter.State, method string, params, results interface{}) error {
+		return nil
+	})
+
+	defer restore()
+
+	_, err := s.apiUnit.WatchActions()
+	c.Assert(err.Error(), gc.Equals, "expected 1 result, got 0")
+}
+
+func (s *unitSuite) TestWatchActionsMoreResults(c *gc.C) {
+	restore := testing.PatchValue(uniter.Call, func(st *uniter.State, method string, args, results interface{}) error {
+		if results, ok := results.(*params.StringsWatchResults); ok {
+			results.Results = make([]params.StringsWatchResult, 2)
+		}
+		return nil
+	})
+
+	defer restore()
+
+	_, err := s.apiUnit.WatchActions()
+	c.Assert(err.Error(), gc.Equals, "expected 1 result, got 2")
+}
+
 func (s *unitSuite) TestServiceNameAndTag(c *gc.C) {
 	c.Assert(s.apiUnit.ServiceName(), gc.Equals, "wordpress")
 	c.Assert(s.apiUnit.ServiceTag(), gc.Equals, "service-wordpress")

state/api/uniter/uniter.go

@@ -36,8 +36,12 @@ func NewState(caller base.Caller, authTag names.UnitTag) *State {
 	}
 }
 
-func (st *State) call(method string, params, results interface{}) error {
-	return st.caller.Call(uniterFacade, "", method, params, results)
+var call = func(st *State, method string, args, results interface{}) error {
+	return st.caller.Call(uniterFacade, "", method, args, results)
+}
+
+func (st *State) call(method string, args, results interface{}) error {
+	return call(st, method, args, results)
 }
 
 // life requests the lifecycle of the given entity from the server.

state/apiserver/uniter/uniter.go

@@ -432,6 +432,22 @@ func (u *UniterAPI) watchOneUnitConfigSettings(tag string) (string, error) {
 	}
 	return "", watcher.MustErr(watch)
 }
+func (u *UniterAPI) watchOneUnitActions(tag string) (params.StringsWatchResult, error) {
+	nothing := params.StringsWatchResult{}
+	unit, err := u.getUnit(tag)
+	if err != nil {
+		return nothing, err
+	}
+	watch := unit.WatchActions()
+
+	if changes, ok := <-watch.Changes(); ok {
+		return params.StringsWatchResult{
+			StringsWatcherId: u.resources.Register(watch),
+			Changes:          changes,
+		}, nil
+	}
+	return nothing, watcher.MustErr(watch)
+}
 
 // WatchConfigSettings returns a NotifyWatcher for observing changes
 // to each unit's service configuration settings. See also
@@ -456,6 +472,34 @@ func (u *UniterAPI) WatchConfigSettings(args params.Entities) (params.NotifyWatc
 	return result, nil
 }
 
+// WatchActions returns an ActionWatcher for observing incoming action calls
+// to a unit.  See also state/watcher.go Unit.WatchActions().  This method
+// is called from state/api/uniter/uniter.go WatchActions().
+func (u *UniterAPI) WatchActions(args params.Entities) (params.StringsWatchResults, error) {
+	nothing := params.StringsWatchResults{}
+
+	result := params.StringsWatchResults{
+		Results: make([]params.StringsWatchResult, len(args.Entities)),
+	}
+	canAccess, err := u.accessUnit()
+	if err != nil {
+		return nothing, err
+	}
+	for i, entity := range args.Entities {
+		_, err := names.ParseUnitTag(entity.Tag)
+		if err != nil {
+			return nothing, err
+		}
+
+		err = common.ErrPerm
+		if canAccess(entity.Tag) {
+			result.Results[i], err = u.watchOneUnitActions(entity.Tag)
+		}
+		result.Results[i].Error = common.ServerError(err)
+	}
+	return result, nil
+}
+
 // ConfigSettings returns the complete set of service charm config
 // settings available to each given unit.
 func (u *UniterAPI) ConfigSettings(args params.Entities) (params.ConfigSettingsResults, error) {
@@ -696,6 +740,8 @@ func (u *UniterAPI) getOneActionByTag(tag names.ActionTag) (params.ActionsQueryR
 	return result, nil
 }
 
+// Actions returns the Actions by Tags passed and ensures that the Unit asking
+// for them is the same Unit that has the Actions.
 func (u *UniterAPI) Actions(args params.Entities) (params.ActionsQueryResults, error) {
 	nothing := params.ActionsQueryResults{}
 

state/apiserver/uniter/uniter_test.go

@@ -749,6 +749,127 @@ func (s *uniterSuite) TestWatchConfigSettings(c *gc.C) {
 	wc.AssertNoChange()
 }
 
+func (s *uniterSuite) TestWatchActions(c *gc.C) {
+	err := s.wordpressUnit.SetCharmURL(s.wpCharm.URL())
+	c.Assert(err, gc.IsNil)
+
+	c.Assert(s.resources.Count(), gc.Equals, 0)
+
+	args := params.Entities{Entities: []params.Entity{
+		{Tag: "unit-mysql-0"},
+		{Tag: "unit-wordpress-0"},
+		{Tag: "unit-foo-42"},
+	}}
+	result, err := s.uniter.WatchActions(args)
+	c.Assert(err, gc.IsNil)
+	c.Assert(result, gc.DeepEquals, params.StringsWatchResults{
+		Results: []params.StringsWatchResult{
+			{Error: apiservertesting.ErrUnauthorized},
+			{StringsWatcherId: "1", Changes: []string{}},
+			{Error: apiservertesting.ErrUnauthorized},
+		},
+	})
+
+	// Verify the resource was registered and stop when done
+	c.Assert(s.resources.Count(), gc.Equals, 1)
+	resource := s.resources.Get("1")
+	defer statetesting.AssertStop(c, resource)
+
+	// Check that the Watch has consumed the initial event ("returned" in
+	// the Watch call)
+	wc := statetesting.NewStringsWatcherC(c, s.State, resource.(state.StringsWatcher))
+	wc.AssertNoChange()
+
+	addedAction, err := s.wordpressUnit.AddAction("snapshot", nil)
+
+	wc.AssertChange(addedAction.Id())
+	wc.AssertNoChange()
+}
+
+func (s *uniterSuite) TestWatchPreexistingActions(c *gc.C) {
+	err := s.wordpressUnit.SetCharmURL(s.wpCharm.URL())
+	c.Assert(err, gc.IsNil)
+
+	c.Assert(s.resources.Count(), gc.Equals, 0)
+
+	firstAction, err := s.wordpressUnit.AddAction("backup", nil)
+	c.Assert(err, gc.IsNil)
+	secondAction, err := s.wordpressUnit.AddAction("snapshot", nil)
+	c.Assert(err, gc.IsNil)
+
+	args := params.Entities{Entities: []params.Entity{
+		{Tag: "unit-wordpress-0"},
+	}}
+
+	result, err := s.uniter.WatchActions(args)
+	c.Assert(err, gc.IsNil)
+	c.Assert(result, gc.DeepEquals, params.StringsWatchResults{
+		Results: []params.StringsWatchResult{
+			{StringsWatcherId: "1", Changes: []string{
+				firstAction.Id(),
+				secondAction.Id(),
+			}},
+		},
+	})
+
+	// Verify the resource was registered and stop when done
+	c.Assert(s.resources.Count(), gc.Equals, 1)
+	resource := s.resources.Get("1")
+	defer statetesting.AssertStop(c, resource)
+
+	// Check that the Watch has consumed the initial event ("returned" in
+	// the Watch call)
+	wc := statetesting.NewStringsWatcherC(c, s.State, resource.(state.StringsWatcher))
+	// TODO: @jcw4 -- this should be:
+	// wc.AssertNoChange()
+	wc.AssertChange(firstAction.Id(), secondAction.Id())
+
+	addedAction, err := s.wordpressUnit.AddAction("backup", nil)
+	c.Assert(err, gc.IsNil)
+	wc.AssertChange(addedAction.Id())
+	wc.AssertNoChange()
+}
+
+func (s *uniterSuite) TestWatchActionsMalformedTag(c *gc.C) {
+	args := params.Entities{Entities: []params.Entity{
+		{Tag: "ewenit-mysql-0"},
+	}}
+	_, err := s.uniter.WatchActions(args)
+	c.Assert(err, gc.NotNil)
+	c.Assert(err.Error(), gc.Equals, `"ewenit-mysql-0" is not a valid tag`)
+}
+
+func (s *uniterSuite) TestWatchActionsMalformedUnitName(c *gc.C) {
+	args := params.Entities{Entities: []params.Entity{
+		{Tag: "unit-mysql-01"},
+	}}
+	_, err := s.uniter.WatchActions(args)
+	c.Assert(err, gc.NotNil)
+	c.Assert(err.Error(), gc.Equals, `"unit-mysql-01" is not a valid unit tag`)
+}
+
+func (s *uniterSuite) TestWatchActionsNotUnit(c *gc.C) {
+	args := params.Entities{Entities: []params.Entity{
+		{Tag: "action-mysql/0_a_0"},
+	}}
+	_, err := s.uniter.WatchActions(args)
+	c.Assert(err, gc.NotNil)
+	c.Assert(err.Error(), gc.Equals, `"action-mysql/0_a_0" is not a valid unit tag`)
+}
+
+func (s *uniterSuite) TestWatchActionsPermissionDenied(c *gc.C) {
+	args := params.Entities{Entities: []params.Entity{
+		{Tag: "unit-nonexistentgarbage-0"},
+	}}
+	results, err := s.uniter.WatchActions(args)
+	c.Assert(err, gc.IsNil)
+	c.Assert(results, gc.NotNil)
+	c.Assert(len(results.Results), gc.Equals, 1)
+	result := results.Results[0]
+	c.Assert(result.Error, gc.NotNil)
+	c.Assert(result.Error.Message, gc.Equals, "permission denied")
+}
+
 func (s *uniterSuite) TestConfigSettings(c *gc.C) {
 	err := s.wordpressUnit.SetCharmURL(s.wpCharm.URL())
 	c.Assert(err, gc.IsNil)