func (s *InstancePollerSuite) TestWatchModelMachinesSuccess(c *gc.C) {
// Add a couple of machines.
s.st.SetMachineInfo(c, machineInfo{id: "2"})
s.st.SetMachineInfo(c, machineInfo{id: "1"})
expectedResult := params.StringsWatchResult{
Error: nil,
StringsWatcherId: "1",
Changes: []string{"1", "2"}, // initial event (sorted ids)
}
result, err := s.api.WatchModelMachines()
c.Assert(err, jc.ErrorIsNil)
c.Assert(result, jc.DeepEquals, expectedResult)
// Verify the watcher resource was registered.
c.Assert(s.resources.Count(), gc.Equals, 1)
resource1 := s.resources.Get("1")
defer func() {
if resource1 != nil {
statetesting.AssertStop(c, resource1)
}
}()
// Check that the watcher has consumed the initial event
wc1 := statetesting.NewStringsWatcherC(c, s.st, resource1.(state.StringsWatcher))
wc1.AssertNoChange()
s.st.CheckCallNames(c, "WatchModelMachines")
// Add another watcher to verify events coalescence.
result, err = s.api.WatchModelMachines()
c.Assert(err, jc.ErrorIsNil)
expectedResult.StringsWatcherId = "2"
c.Assert(result, jc.DeepEquals, expectedResult)
s.st.CheckCallNames(c, "WatchModelMachines", "WatchModelMachines")
c.Assert(s.resources.Count(), gc.Equals, 2)
resource2 := s.resources.Get("2")
defer statetesting.AssertStop(c, resource2)
wc2 := statetesting.NewStringsWatcherC(c, s.st, resource2.(state.StringsWatcher))
wc2.AssertNoChange()
// Remove machine 1, check it's reported.
s.st.RemoveMachine(c, "1")
wc1.AssertChangeInSingleEvent("1")
// Make separate changes, check they're combined.
s.st.SetMachineInfo(c, machineInfo{id: "2", life: state.Dying})
s.st.SetMachineInfo(c, machineInfo{id: "3"})
s.st.RemoveMachine(c, "42") // ignored
wc1.AssertChangeInSingleEvent("2", "3")
wc2.AssertChangeInSingleEvent("1", "2", "3")
// Stop the first watcher and assert its changes chan is closed.
c.Assert(resource1.Stop(), jc.ErrorIsNil)
wc1.AssertClosed()
resource1 = nil
}
// WatchEnvironMachines returns a StringsWatcher that notifies of
// changes to the life cycles of the top level machines in the current
// environment.
func (e *EnvironMachinesWatcher) WatchEnvironMachines() (params.StringsWatchResult, error) {
result := params.StringsWatchResult{}
if !e.authorizer.AuthEnvironManager() {
return result, ErrPerm
}
watch := e.st.WatchEnvironMachines()
// Consume the initial event and forward it to the result.
if changes, ok := <-watch.Changes(); ok {
result.StringsWatcherId = e.resources.Register(watch)
result.Changes = changes
} else {
err := watcher.EnsureErr(watch)
return result, fmt.Errorf("cannot obtain initial environment machines: %v", err)
}
return result, nil
}
func (s *StorageProvisionerAPI) watchStorageEntities(
args params.Entities,
watchEnvironStorage func() state.StringsWatcher,
watchMachineStorage func(names.MachineTag) state.StringsWatcher,
) (params.StringsWatchResults, error) {
canAccess, err := s.getScopeAuthFunc()
if err != nil {
return params.StringsWatchResults{}, common.ServerError(common.ErrPerm)
}
results := params.StringsWatchResults{
Results: make([]params.StringsWatchResult, len(args.Entities)),
}
one := func(arg params.Entity) (string, []string, error) {
tag, err := names.ParseTag(arg.Tag)
if err != nil || !canAccess(tag) {
return "", nil, common.ErrPerm
}
var w state.StringsWatcher
if tag, ok := tag.(names.MachineTag); ok {
w = watchMachineStorage(tag)
} else {
w = watchEnvironStorage()
}
if changes, ok := <-w.Changes(); ok {
return s.resources.Register(w), changes, nil
}
return "", nil, watcher.EnsureErr(w)
}
for i, arg := range args.Entities {
var result params.StringsWatchResult
id, changes, err := one(arg)
if err != nil {
result.Error = common.ServerError(err)
} else {
result.StringsWatcherId = id
result.Changes = changes
}
results.Results[i] = result
}
return results, nil
}