Fix gcplogs memory/connection leak

phaas · phaas · commit ef553e14a4e2 · 2020-09-30T17:45:19.000-07:00
The cloud logging client should be closed when the log driver is closed. Otherwise dockerd will keep a gRPC connection to the logging endpoint open indefinitely.

This results in a slow leak of tcp sockets (1) and memory (~200Kb) any time that a container using `--log-driver=gcplogs` is terminates.

Signed-off-by: Patrick Haas &lt;patrickhaas@google.com&gt;
diff --git a/daemon/logger/gcplogs/gcplogging.go b/daemon/logger/gcplogs/gcplogging.go
@@ -54,6 +54,7 @@ func init() {
 }
 
 type gcplogs struct {
+	client    *logging.Client
 	logger    *logging.Logger
 	instance  *instanceInfo
 	container *containerInfo
@@ -170,6 +171,7 @@ func New(info logger.Info) (logger.Logger, error) {
 	}
 
 	l := &gcplogs{
+		client: c,
 		logger: lg,
 		container: &containerInfo{
 			Name:      info.ContainerName,
@@ -237,7 +239,7 @@ func (l *gcplogs) Log(m *logger.Message) error {
 
 func (l *gcplogs) Close() error {
 	l.logger.Flush()
-	return nil
+	return l.client.Close()
 }
 
 func (l *gcplogs) Name() string {

Original file line number	Diff line number	Diff line change
`@@ -54,6 +54,7 @@ func init() {`
`54`	`54`	`}`
`55`	`55`
`56`	`56`	`type gcplogs struct {`
	`57`	`+ client *logging.Client`
`57`	`58`	`logger *logging.Logger`
`58`	`59`	`instance *instanceInfo`
`59`	`60`	`container *containerInfo`
`@@ -170,6 +171,7 @@ func New(info logger.Info) (logger.Logger, error) {`
`170`	`171`	`}`
`171`	`172`
`172`	`173`	`l := &gcplogs{`
	`174`	`+ client: c,`
`173`	`175`	`logger: lg,`
`174`	`176`	`container: &containerInfo{`
`175`	`177`	`Name: info.ContainerName,`
`@@ -237,7 +239,7 @@ func (l gcplogs) Log(m logger.Message) error {`
`237`	`239`
`238`	`240`	`func (l *gcplogs) Close() error {`
`239`	`241`	`l.logger.Flush()`
`240`		`- return nil`
	`242`	`+ return l.client.Close()`
`241`	`243`	`}`
`242`	`244`
`243`	`245`	`func (l *gcplogs) Name() string {`