Show error for JS plugin watcher

Signed-off-by: Vikram Yadav <yvikram@vmware.com>

#1273

changelogs/unreleased/2776-xtreme-vikram-yadav

@@ -0,0 +1 @@
+logged better errors for JS plugin watcher

pkg/plugin/manager.go

@@ -364,13 +364,18 @@ func (m *Manager) watchJS(ctx context.Context) {
  }
  }()
 
+ watchedDirs := []string{}
  for _, dir := range dirs {
  if err := watcher.Add(dir); err != nil {
- logger.Warnf("unable to add %s to JavaScript plugin watcher", dir)
+ logger.Warnf("Unable to add %s to JavaScript plugin watcher. Error: %s\n", dir, err)
+ } else {
+ watchedDirs = append(watchedDirs, dir)
  }
  }
 
- logger.Infof("watching for new JavaScript plugins in %q", dirs)
+ if len(watchedDirs) > 0 {
+ logger.Infof("Watching for new JavaScript plugins in %q\n", dirs)
+ }
 
  writeEvents := make(map[string]bool)
  updatePlugin := func(name string) {
@@ -392,26 +397,26 @@ func (m *Manager) watchJS(ctx context.Context) {
  case <-ctx.Done():
  logger.Infof("context cancelled shutting down JavaScript plugin watcher.")
  return
- case event, ok := <-watcher.Events:
+ case ev, ok := <-watcher.Events:
  if !ok {
  logger.Errorf("bad event returned from JavaScript plugin watcher")
  return
  }
- if event.Op&(fsnotify.Chmod|fsnotify.Write|fsnotify.Create) == fsnotify.Chmod {
+ if ev.Op&(fsnotify.Chmod|fsnotify.Write|fsnotify.Create) == fsnotify.Chmod {
  continue
  }
- if IsJavaScriptPlugin(event.Name) {
- if event.Op&fsnotify.Remove == fsnotify.Remove {
- jsPlugin, ok := m.store.GetJS(event.Name)
+ if IsJavaScriptPlugin(ev.Name) {
+ if ev.Op&fsnotify.Remove == fsnotify.Remove {
+ jsPlugin, ok := m.store.GetJS(ev.Name)
  if ok {
  if err := m.unregisterJSPlugin(ctx, jsPlugin); err != nil {
  logger.Errorf("unregistering: %w", err)
  }
- m.store.RemoveJS(event.Name)
- logger.Infof("removing: JavaScript plugin: %s", event.Name)
+ m.store.RemoveJS(ev.Name)
+ logger.Infof("removing: JavaScript plugin: %s", ev.Name)
  }
- } else if event.Op&fsnotify.Write == fsnotify.Write {
- writeEvents[event.Name] = true
+ } else if ev.Op&fsnotify.Write == fsnotify.Write {
+ writeEvents[ev.Name] = true
  }
  }
  case err, ok := <-watcher.Errors: