Added basic Flexvolume dynamic plugin discovery e2e test; added Flexvolume prober unit tests.

pkg/util/filesystem/watcher.go

@@ -0,0 +1,89 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package filesystem
+
+import (
+	"github.com/fsnotify/fsnotify"
+)
+
+// FSWatcher is a callback-based filesystem watcher abstraction for fsnotify.
+type FSWatcher interface {
+	// Initializes the watcher with the given watch handlers.
+	// Called before all other methods.
+	Init(FSEventHandler, FSErrorHandler) error
+
+	// Starts listening for events and errors.
+	// When an event or error occurs, the corresponding handler is called.
+	Run()
+
+	// Add a filesystem path to watch
+	AddWatch(path string) error
+}
+
+// FSEventHandler is called when a fsnotify event occurs.
+type FSEventHandler func(event fsnotify.Event)
+
+// FSErrorHandler is called when a fsnotify error occurs.
+type FSErrorHandler func(err error)
+
+type fsnotifyWatcher struct {
+	watcher      *fsnotify.Watcher
+	eventHandler FSEventHandler
+	errorHandler FSErrorHandler
+}
+
+var _ FSWatcher = &fsnotifyWatcher{}
+
+// NewFsnotifyWatcher returns an implementation of FSWatcher that continuously listens for
+// fsnotify events and calls the event handler as soon as an event is received.
+func NewFsnotifyWatcher() FSWatcher {
+	return &fsnotifyWatcher{}
+}
+
+func (w *fsnotifyWatcher) AddWatch(path string) error {
+	return w.watcher.Add(path)
+}
+
+func (w *fsnotifyWatcher) Init(eventHandler FSEventHandler, errorHandler FSErrorHandler) error {
+	var err error
+	w.watcher, err = fsnotify.NewWatcher()
+	if err != nil {
+		return err
+	}
+
+	w.eventHandler = eventHandler
+	w.errorHandler = errorHandler
+	return nil
+}
+
+func (w *fsnotifyWatcher) Run() {
+	go func() {
+		defer w.watcher.Close()
+		for {
+			select {
+			case event := <-w.watcher.Events:
+				if w.eventHandler != nil {
+					w.eventHandler(event)
+				}
+			case err := <-w.watcher.Errors:
+				if w.errorHandler != nil {
+					w.errorHandler(err)
+				}
+			}
+		}
+	}()
+}