When daemon is in startup process, could not start container

Description:
 When docker is in startup process and containerd sends an "process exit" event to docker.
 If the container config '--restart=always', restartmanager will start this container very soon.

 But some initialization is not done, e.g. `daemon.netController`,when visit, docker would panic.

Signed-off-by: Wentao Zhang <zhangwentao234@huawei.com>

Author: moypray

daemon/daemon.go

@@ -110,7 +110,8 @@ type Daemon struct {
 	seccompProfile     []byte
 	seccompProfilePath string
 
-	hosts map[string]bool // hosts stores the addresses the daemon is listening on
+	hosts       map[string]bool // hosts stores the addresses the daemon is listening on
+	startupDone chan struct{}
 }
 
 // StoreHosts stores the addresses the daemon is listening on
@@ -542,7 +543,10 @@ func NewDaemon(config *Config, registryService registry.Service, containerdRemot
 	}
 	os.Setenv("TMPDIR", realTmp)
 
-	d := &Daemon{configStore: config}
+	d := &Daemon{
+		configStore: config,
+		startupDone: make(chan struct{}),
+	}
 	// Ensure the daemon is properly shutdown if there is a failure during
 	// initialization
 	defer func() {
@@ -726,6 +730,7 @@ func NewDaemon(config *Config, registryService registry.Service, containerdRemot
 	if err := d.restore(); err != nil {
 		return nil, err
 	}
+	close(d.startupDone)
 
 	// FIXME: this method never returns an error
 	info, _ := d.SystemInfo()
@@ -752,6 +757,10 @@ func NewDaemon(config *Config, registryService registry.Service, containerdRemot
 	return d, nil
 }
 
+func (daemon *Daemon) waitForStartupDone() {
+	<-daemon.startupDone
+}
+
 func (daemon *Daemon) shutdownContainer(c *container.Container) error {
 	stopTimeout := c.StopTimeout()
 	// TODO(windows): Handle docker restart with paused containers

daemon/monitor.go

@@ -56,6 +56,10 @@ func (daemon *Daemon) StateChanged(id string, e libcontainerd.StateInfo) error {
 			go func() {
 				err := <-wait
 				if err == nil {
+					// daemon.netController is initialized when daemon is restoring containers.
+					// But containerStart will use daemon.netController segment.
+					// So to avoid panic at startup process, here must wait util daemon restore done.
+					daemon.waitForStartupDone()
 					if err = daemon.containerStart(c, "", "", false); err != nil {
 						logrus.Debugf("failed to restart container: %+v", err)
 					}