package command import ( "sync" "github.com/docker/docker/api/types/events" "github.com/sirupsen/logrus" ) // EventHandler is abstract interface for user to customize // own handle functions of each type of events type EventHandler interface { Handle(action events.Action, h func(events.Message)) Watch(c <-chan events.Message) } // InitEventHandler initializes and returns an EventHandler func InitEventHandler() EventHandler { return &eventHandler{handlers: make(map[events.Action]func(events.Message))} } type eventHandler struct { handlers map[events.Action]func(events.Message) mu sync.Mutex } func (w *eventHandler) Handle(action events.Action, h func(events.Message)) { w.mu.Lock() w.handlers[action] = h w.mu.Unlock() } // Watch ranges over the passed in event chan and processes the events based on the // handlers created for a given action. // To stop watching, close the event chan. func (w *eventHandler) Watch(c <-chan events.Message) { for e := range c { w.mu.Lock() h, exists := w.handlers[e.Action] w.mu.Unlock() if !exists { continue } logrus.Debugf("event handler: received event: %v", e) go h(e) } }