func()

in container/raw/watcher.go [176:242]
52 lines of code
14 McCabe index (conditional complexity)

func (w *rawContainerWatcher) processEvent(event *inotify.Event, events chan watcher.ContainerEvent) error {
	// Convert the inotify event type to a container create or delete.
	var eventType watcher.ContainerEventType
	switch {
	case (event.Mask & inotify.InCreate) > 0:
		eventType = watcher.ContainerAdd
	case (event.Mask & inotify.InDelete) > 0:
		eventType = watcher.ContainerDelete
	case (event.Mask & inotify.InMovedFrom) > 0:
		eventType = watcher.ContainerDelete
	case (event.Mask & inotify.InMovedTo) > 0:
		eventType = watcher.ContainerAdd
	default:
		// Ignore other events.
		return nil
	}

	// Derive the container name from the path name.
	var containerName string
	for _, mount := range w.cgroupPaths {
		mountLocation := path.Clean(mount) + "/"
		if strings.HasPrefix(event.Name, mountLocation) {
			containerName = event.Name[len(mountLocation)-1:]
			break
		}
	}
	if containerName == "" {
		return fmt.Errorf("unable to detect container from watch event on directory %q", event.Name)
	}

	// Maintain the watch for the new or deleted container.
	switch eventType {
	case watcher.ContainerAdd:
		// New container was created, watch it.
		alreadyWatched, err := w.watchDirectory(events, event.Name, containerName)
		if err != nil {
			return err
		}

		// Only report container creation once.
		if alreadyWatched {
			return nil
		}
	case watcher.ContainerDelete:
		// Container was deleted, stop watching for it.
		lastWatched, err := w.watcher.RemoveWatch(containerName, event.Name)
		if err != nil {
			return err
		}

		// Only report container deletion once.
		if !lastWatched {
			return nil
		}
	default:
		return fmt.Errorf("unknown event type %v", eventType)
	}

	// Deliver the event.
	events <- watcher.ContainerEvent{
		EventType:   eventType,
		Name:        containerName,
		WatchSource: watcher.Raw,
	}

	return nil
}