Merge pull request #733 from vmarmol/validate

Add debug info to /validate

container/docker/factory.go

@@ -149,6 +149,10 @@ func (self *dockerFactory) CanHandleAndAccept(name string) (bool, bool, error) {
 	return true, canAccept, nil
 }
 
+func (self *dockerFactory) DebugInfo() map[string][]string {
+	return map[string][]string{}
+}
+
 func parseDockerVersion(full_version_string string) ([]int, error) {
 	version_regexp_string := "(\\d+)\\.(\\d+)\\.(\\d+)"
 	version_re := regexp.MustCompile(version_regexp_string)

container/factory.go

@@ -30,6 +30,9 @@ type ContainerHandlerFactory interface {
 
 	// Name of the factory.
 	String() string
+
+	// Returns debugging information. Map of lines per category.
+	DebugInfo() map[string][]string
 }
 
 // TODO(vmarmol): Consider not making this global.
@@ -90,3 +93,17 @@ func ClearContainerHandlerFactories() {
 
 	factories = make([]ContainerHandlerFactory, 0, 4)
 }
+
+func DebugInfo() map[string][]string {
+	factoriesLock.RLock()
+	defer factoriesLock.RUnlock()
+
+	// Get debug information for all factories.
+	out := make(map[string][]string)
+	for _, factory := range factories {
+		for k, v := range factory.DebugInfo() {
+			out[k] = v
+		}
+	}
+	return out
+}

container/factory_test.go

@@ -31,6 +31,10 @@ func (self *mockContainerHandlerFactory) String() string {
 	return self.Name
 }
 
+func (self *mockContainerHandlerFactory) DebugInfo() map[string][]string {
+	return map[string][]string{}
+}
+
 func (self *mockContainerHandlerFactory) CanHandleAndAccept(name string) (bool, bool, error) {
 	return self.CanHandleValue, self.CanAcceptValue, nil
 }

container/raw/factory.go

@@ -36,6 +36,9 @@ type rawFactory struct {
 
 	// Information about mounted filesystems.
 	fsInfo fs.FsInfo
+
+	// Watcher for inotify events.
+	watcher *InotifyWatcher
 }
 
 func (self *rawFactory) String() string {
@@ -43,7 +46,7 @@ func (self *rawFactory) String() string {
 }
 
 func (self *rawFactory) NewContainerHandler(name string) (container.ContainerHandler, error) {
-	return newRawContainerHandler(name, self.cgroupSubsystems, self.machineInfoFactory, self.fsInfo)
+	return newRawContainerHandler(name, self.cgroupSubsystems, self.machineInfoFactory, self.fsInfo, self.watcher)
 }
 
 // The raw factory can handle any container. If --docker_only is set to false, non-docker containers are ignored.
@@ -52,6 +55,23 @@ func (self *rawFactory) CanHandleAndAccept(name string) (bool, bool, error) {
 	return true, accept, nil
 }
 
+func (self *rawFactory) DebugInfo() map[string][]string {
+	out := make(map[string][]string)
+
+	// Get information about inotify watches.
+	watches := self.watcher.GetWatches()
+	lines := make([]string, 0, len(watches))
+	for containerName, cgroupWatches := range watches {
+		lines = append(lines, fmt.Sprintf("%s:", containerName))
+		for _, cg := range cgroupWatches {
+			lines = append(lines, fmt.Sprintf("\t%s", cg))
+		}
+	}
+	out["Inotify watches"] = lines
+
+	return out
+}
+
 func Register(machineInfoFactory info.MachineInfoFactory, fsInfo fs.FsInfo) error {
 	cgroupSubsystems, err := libcontainer.GetCgroupSubsystems()
 	if err != nil {
@@ -61,11 +81,17 @@ func Register(machineInfoFactory info.MachineInfoFactory, fsInfo fs.FsInfo) erro
 		return fmt.Errorf("failed to find supported cgroup mounts for the raw factory")
 	}
 
+	watcher, err := NewInotifyWatcher()
+	if err != nil {
+		return err
+	}
+
 	glog.Infof("Registering Raw factory")
 	factory := &rawFactory{
 		machineInfoFactory: machineInfoFactory,
 		fsInfo:             fsInfo,
 		cgroupSubsystems:   &cgroupSubsystems,
+		watcher:            watcher,
 	}
 	container.RegisterContainerHandlerFactory(factory)
 	return nil

container/raw/handler.go

@@ -62,7 +62,7 @@ type rawContainerHandler struct {
 	externalMounts []mount
 }
 
-func newRawContainerHandler(name string, cgroupSubsystems *libcontainer.CgroupSubsystems, machineInfoFactory info.MachineInfoFactory, fsInfo fs.FsInfo) (container.ContainerHandler, error) {
+func newRawContainerHandler(name string, cgroupSubsystems *libcontainer.CgroupSubsystems, machineInfoFactory info.MachineInfoFactory, fsInfo fs.FsInfo, watcher *InotifyWatcher) (container.ContainerHandler, error) {
 	// Create the cgroup paths.
 	cgroupPaths := make(map[string]string, len(cgroupSubsystems.MountPoints))
 	for key, val := range cgroupSubsystems.MountPoints {
@@ -106,6 +106,7 @@ func newRawContainerHandler(name string, cgroupSubsystems *libcontainer.CgroupSu
 		fsInfo:             fsInfo,
 		hasNetwork:         hasNetwork,
 		externalMounts:     externalMounts,
+		watcher:            watcher,
 	}, nil
 }
 
@@ -501,15 +502,6 @@ func (self *rawContainerHandler) processEvent(event *inotify.Event, events chan
 }
 
 func (self *rawContainerHandler) WatchSubcontainers(events chan container.SubcontainerEvent) error {
-	// Lazily initialize the watcher so we don't use it when not asked to.
-	if self.watcher == nil {
-		w, err := NewInotifyWatcher()
-		if err != nil {
-			return err
-		}
-		self.watcher = w
-	}
-
 	// Watch this container (all its cgroups) and all subdirectories.
 	for _, cgroupPath := range self.cgroupPaths {
 		_, err := self.watchDirectory(cgroupPath, self.name)
@@ -533,7 +525,6 @@ func (self *rawContainerHandler) WatchSubcontainers(events chan container.Subcon
 				err := self.watcher.Close()
 				if err == nil {
 					self.stopWatcher <- err
-					self.watcher = nil
 					return
 				}
 			}
@@ -544,10 +535,6 @@ func (self *rawContainerHandler) WatchSubcontainers(events chan container.Subcon
 }
 
 func (self *rawContainerHandler) StopWatchingSubcontainers() error {
-	if self.watcher == nil {
-		return fmt.Errorf("can't stop watch that has not started for container %q", self.name)
-	}
-
 	// Rendezvous with the watcher thread.
 	self.stopWatcher <- nil
 	return <-self.stopWatcher

manager/manager.go

@@ -107,6 +107,9 @@ type Manager interface {
 
 	// Get details about interesting docker images.
 	DockerImages() ([]DockerImage, error)
+
+	// Returns debugging information. Map of lines per category.
+	DebugInfo() map[string][]string
 }
 
 // New takes a memory storage and returns a new manager.
@@ -1131,3 +1134,7 @@ func (m *manager) DockerInfo() (DockerStatus, error) {
 	}
 	return out, nil
 }
+
+func (m *manager) DebugInfo() map[string][]string {
+	return container.DebugInfo()
+}

validate/validate.go

@@ -313,6 +313,13 @@ func HandleRequest(w http.ResponseWriter, containerManager manager.Manager) erro
 
 	ioSchedulerValidation, desc := validateIoScheduler(containerManager)
 	out += fmt.Sprintf(OutputFormat, "Block device setup", ioSchedulerValidation, desc)
+
+	// Output debug info.
+	debugInfo := containerManager.DebugInfo()
+	for category, lines := range debugInfo {
+		out += fmt.Sprintf(OutputFormat, category, "", strings.Join(lines, "\n\t"))
+	}
+
 	_, err = w.Write([]byte(out))
 	return err
 }