// NewPinger returns an object that can be pinged by calling its Ping method.
// If this method is not called frequently enough, the connection will be
// dropped.
func NewPinger(st *state.State, resources facade.Resources, authorizer facade.Authorizer) (Pinger, error) {
pingTimeout, ok := resources.Get("pingTimeout").(*pingTimeout)
if !ok {
return nullPinger{}, nil
}
return pingTimeout, nil
}
func extractResourceValue(resources facade.Resources, key string) (string, error) {
res := resources.Get(key)
strRes, ok := res.(common.StringResource)
if !ok {
if res == nil {
strRes = ""
} else {
return "", errors.Errorf("invalid %s resource: %v", key, res)
}
}
return strRes.String(), nil
}
func newMachineStorageIdsWatcher(
st *state.State,
resources facade.Resources,
auth facade.Authorizer,
id string,
parser func([]string) ([]params.MachineStorageId, error),
) (facade.Facade, error) {
if !isAgent(auth) {
return nil, common.ErrPerm
}
watcher, ok := resources.Get(id).(state.StringsWatcher)
if !ok {
return nil, common.ErrUnknownWatcher
}
return &srvMachineStorageIdsWatcher{watcher, id, resources, parser}, nil
}
func leadershipSettingsAccessorFactory(
st *state.State,
resources facade.Resources,
auth facade.Authorizer,
) *leadershipapiserver.LeadershipSettingsAccessor {
registerWatcher := func(serviceId string) (string, error) {
service, err := st.Application(serviceId)
if err != nil {
return "", err
}
w := service.WatchLeaderSettings()
if _, ok := <-w.Changes(); ok {
return resources.Register(w), nil
}
return "", watcher.EnsureErr(w)
}
getSettings := func(serviceId string) (map[string]string, error) {
service, err := st.Application(serviceId)
if err != nil {
return nil, err
}
return service.LeaderSettings()
}
writeSettings := func(token leadership.Token, serviceId string, settings map[string]string) error {
service, err := st.Application(serviceId)
if err != nil {
return err
}
return service.UpdateLeaderSettings(token, settings)
}
return leadershipapiserver.NewLeadershipSettingsAccessor(
auth,
registerWatcher,
getSettings,
st.LeadershipChecker().LeadershipCheck,
writeSettings,
)
}