// WatchContainers returns a StringsWatcher that notifies of changes
// to the lifecycles of containers of the specified type on the machine.
func (m *Machine) WatchContainers(ctype instance.ContainerType) (watcher.StringsWatcher, error) {
if string(ctype) == "" {
return nil, errors.New("container type must be specified")
}
supported := false
for _, c := range instance.ContainerTypes {
if ctype == c {
supported = true
break
}
}
if !supported {
return nil, fmt.Errorf("unsupported container type %q", ctype)
}
var results params.StringsWatchResults
args := params.WatchContainers{
Params: []params.WatchContainer{
{MachineTag: m.tag, ContainerType: string(ctype)},
},
}
err := m.st.call("WatchContainers", 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(m.st.caller, result)
return w, nil
}
// WatchEnvironMachines returns a StringsWatcher that notifies of
// changes to the life cycles of the top level machines in the current
// environment.
func (st *State) WatchEnvironMachines() (watcher.StringsWatcher, error) {
var result params.StringsWatchResult
err := st.call("WatchEnvironMachines", nil, &result)
if err != nil {
return nil, err
}
if err := result.Error; err != nil {
return nil, result.Error
}
w := watcher.NewStringsWatcher(st.caller, result)
return w, nil
}
// WatchRelations returns a StringsWatcher that notifies of changes to
// the lifecycles of relations involving s.
func (s *Service) WatchRelations() (watcher.StringsWatcher, error) {
var results params.StringsWatchResults
args := params.Entities{
Entities: []params.Entity{{Tag: s.tag}},
}
err := s.st.call("WatchServiceRelations", 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(s.st.caller, result)
return w, nil
}
// WatchAllContainers returns a StringsWatcher that notifies of changes
// to the lifecycles of all containers on the machine.
func (m *Machine) WatchAllContainers() (watcher.StringsWatcher, error) {
var results params.StringsWatchResults
args := params.WatchContainers{
Params: []params.WatchContainer{
{MachineTag: m.tag},
},
}
err := m.st.call("WatchContainers", 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(m.st.caller, result)
return w, nil
}