Bump cAdvisor (and dependencies) godeps version

vendor/github.com/google/cadvisor/manager/watcher/raw/raw.go

@@ -0,0 +1,214 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// 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 container defines types for sub-container events and also
+// defines an interface for container operation handlers.
+package raw
+
+import (
+	"fmt"
+	"io/ioutil"
+	"path"
+	"strings"
+
+	"github.com/google/cadvisor/container/common"
+	"github.com/google/cadvisor/container/libcontainer"
+	"github.com/google/cadvisor/manager/watcher"
+
+	"github.com/golang/glog"
+	"golang.org/x/exp/inotify"
+)
+
+type rawContainerWatcher struct {
+	// Absolute path to the root of the cgroup hierarchies
+	cgroupPaths map[string]string
+
+	cgroupSubsystems *libcontainer.CgroupSubsystems
+
+	// Inotify event watcher.
+	watcher *common.InotifyWatcher
+
+	// Signal for watcher thread to stop.
+	stopWatcher chan error
+}
+
+func NewRawContainerWatcher() (watcher.ContainerWatcher, error) {
+	cgroupSubsystems, err := libcontainer.GetCgroupSubsystems()
+	if err != nil {
+		return nil, fmt.Errorf("failed to get cgroup subsystems: %v", err)
+	}
+	if len(cgroupSubsystems.Mounts) == 0 {
+		return nil, fmt.Errorf("failed to find supported cgroup mounts for the raw factory")
+	}
+
+	watcher, err := common.NewInotifyWatcher()
+	if err != nil {
+		return nil, err
+	}
+
+	rawWatcher := &rawContainerWatcher{
+		cgroupPaths:      common.MakeCgroupPaths(cgroupSubsystems.MountPoints, "/"),
+		cgroupSubsystems: &cgroupSubsystems,
+		watcher:          watcher,
+		stopWatcher:      make(chan error),
+	}
+
+	return rawWatcher, nil
+}
+
+func (self *rawContainerWatcher) Start(events chan watcher.ContainerEvent) error {
+	// Watch this container (all its cgroups) and all subdirectories.
+	for _, cgroupPath := range self.cgroupPaths {
+		_, err := self.watchDirectory(cgroupPath, "/")
+		if err != nil {
+			return err
+		}
+	}
+
+	// Process the events received from the kernel.
+	go func() {
+		for {
+			select {
+			case event := <-self.watcher.Event():
+				err := self.processEvent(event, events)
+				if err != nil {
+					glog.Warningf("Error while processing event (%+v): %v", event, err)
+				}
+			case err := <-self.watcher.Error():
+				glog.Warningf("Error while watching %q:", "/", err)
+			case <-self.stopWatcher:
+				err := self.watcher.Close()
+				if err == nil {
+					self.stopWatcher <- err
+					return
+				}
+			}
+		}
+	}()
+
+	return nil
+}
+
+func (self *rawContainerWatcher) Stop() error {
+	// Rendezvous with the watcher thread.
+	self.stopWatcher <- nil
+	return <-self.stopWatcher
+}
+
+// Watches the specified directory and all subdirectories. Returns whether the path was
+// already being watched and an error (if any).
+func (self *rawContainerWatcher) watchDirectory(dir string, containerName string) (bool, error) {
+	alreadyWatching, err := self.watcher.AddWatch(containerName, dir)
+	if err != nil {
+		return alreadyWatching, err
+	}
+
+	// Remove the watch if further operations failed.
+	cleanup := true
+	defer func() {
+		if cleanup {
+			_, err := self.watcher.RemoveWatch(containerName, dir)
+			if err != nil {
+				glog.Warningf("Failed to remove inotify watch for %q: %v", dir, err)
+			}
+		}
+	}()
+
+	// TODO(vmarmol): We should re-do this once we're done to ensure directories were not added in the meantime.
+	// Watch subdirectories as well.
+	entries, err := ioutil.ReadDir(dir)
+	if err != nil {
+		return alreadyWatching, err
+	}
+	for _, entry := range entries {
+		if entry.IsDir() {
+			// TODO(vmarmol): We don't have to fail here, maybe we can recover and try to get as many registrations as we can.
+			_, err = self.watchDirectory(path.Join(dir, entry.Name()), path.Join(containerName, entry.Name()))
+			if err != nil {
+				return alreadyWatching, err
+			}
+		}
+	}
+
+	cleanup = false
+	return alreadyWatching, nil
+}
+
+func (self *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.IN_CREATE) > 0:
+		eventType = watcher.ContainerAdd
+	case (event.Mask & inotify.IN_DELETE) > 0:
+		eventType = watcher.ContainerDelete
+	case (event.Mask & inotify.IN_MOVED_FROM) > 0:
+		eventType = watcher.ContainerDelete
+	case (event.Mask & inotify.IN_MOVED_TO) > 0:
+		eventType = watcher.ContainerAdd
+	default:
+		// Ignore other events.
+		return nil
+	}
+
+	// Derive the container name from the path name.
+	var containerName string
+	for _, mount := range self.cgroupSubsystems.Mounts {
+		mountLocation := path.Clean(mount.Mountpoint) + "/"
+		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 := self.watchDirectory(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 := self.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
+}