Fix goroutine leak in docker fs handler logic.

Signed-off-by: Vishnu kannan <vishnuk@google.com>

container/container.go

@@ -78,4 +78,7 @@ type ContainerHandler interface {
 
 	// Returns whether the container still exists.
 	Exists() bool
+
+	// Cleanup frees up any resources being held like fds or go routines, etc.
+	Cleanup()
 }

container/docker/handler.go

@@ -160,6 +160,10 @@ func newDockerContainerHandler(
 	return handler, nil
 }
 
+func (self *dockerContainerHandler) Cleanup() {
+	self.fsHandler.stop()
+}
+
 func (self *dockerContainerHandler) ContainerReference() (info.ContainerReference, error) {
 	return info.ContainerReference{
 		Name:      self.name,

container/mock.go

@@ -51,6 +51,8 @@ func (self *MockContainerHandler) ContainerReference() (info.ContainerReference,
 	return args.Get(0).(info.ContainerReference), args.Error(1)
 }
 
+func (self *MockContainerHandler) Cleanup() {}
+
 func (self *MockContainerHandler) GetSpec() (info.ContainerSpec, error) {
 	args := self.Called()
 	return args.Get(0).(info.ContainerSpec), args.Error(1)

container/raw/handler.go

@@ -166,6 +166,9 @@ func (self *rawContainerHandler) GetRootNetworkDevices() ([]info.NetInfo, error)
 	return nd, nil
 }
 
+// Nothing to clean up.
+func (self *rawContainerHandler) Cleanup() {}
+
 func (self *rawContainerHandler) GetSpec() (info.ContainerSpec, error) {
 	var spec info.ContainerSpec
 

manager/container.go

@@ -373,6 +373,8 @@ func (c *containerData) housekeeping() {
 	for {
 		select {
 		case <-c.stop:
+			// Cleanup container resources before stopping housekeeping.
+			c.handler.Cleanup()
 			// Stop housekeeping when signaled.
 			return
 		default: