package hooks import ( "context" current "github.com/containers/libpod/pkg/hooks/1.0.0" "github.com/fsnotify/fsnotify" "github.com/sirupsen/logrus" ) // Monitor dynamically monitors hook directories for additions, // updates, and removals. // // This function writes two empty structs to the sync channel: the // first is written after the watchers are established and the second // when this function exits. The expected usage is: // // ctx, cancel := context.WithCancel(context.Background()) // sync := make(chan error, 2) // go m.Monitor(ctx, sync) // err := <-sync // block until writers are established // if err != nil { // return err // failed to establish watchers // } // // do stuff // cancel() // err = <-sync // block until monitor finishes func (m *Manager) Monitor(ctx context.Context, sync chan<- error) { watcher, err := fsnotify.NewWatcher() if err != nil { sync <- err return } defer watcher.Close() for _, dir := range m.directories { err = watcher.Add(dir) if err != nil { logrus.Errorf("failed to watch %q for hooks", dir) sync <- err return } logrus.Debugf("monitoring %q for hooks", dir) } sync <- nil for { select { case event := <-watcher.Events: m.hooks = make(map[string]*current.Hook) for _, dir := range m.directories { err = ReadDir(dir, m.extensionStages, m.hooks) if err != nil { logrus.Errorf("failed loading hooks for %s: %v", event.Name, err) } } case <-ctx.Done(): err = ctx.Err() logrus.Debugf("hook monitoring canceled: %v", err) sync <- err close(sync) return } } }