Fix critical bug: can't restart a restarting container

When user try to restart a restarting container, docker client report
error: "container is already active", and container will be stopped
instead be restarted which is seriously wrong.

What's more critical is that when user try to start this container
again, it will always fail.

This error can also be reproduced with a `docker stop`+`docker start`.

And this commit will fix the bug.

Signed-off-by: Zhang Wei <zhangwei555@huawei.com>

daemon/kill.go

@@ -3,6 +3,7 @@ package daemon
 import (
 	"fmt"
 	"runtime"
+	"strings"
 	"syscall"
 	"time"
 
@@ -81,7 +82,14 @@ func (daemon *Daemon) killWithSignal(container *container.Container, sig int) er
 	}
 
 	if err := daemon.kill(container, sig); err != nil {
-		return fmt.Errorf("Cannot kill container %s: %s", container.ID, err)
+		err = fmt.Errorf("Cannot kill container %s: %s", container.ID, err)
+		// if container or process not exists, ignore the error
+		if strings.Contains(err.Error(), "container not found") ||
+			strings.Contains(err.Error(), "no such process") {
+			logrus.Warnf("%s", err.Error())
+		} else {
+			return err
+		}
 	}
 
 	attributes := map[string]string{

integration-cli/docker_cli_restart_test.go

@@ -218,3 +218,32 @@ func (s *DockerSuite) TestRestartPolicyAfterRestart(c *check.C) {
 	err = waitInspect(id, "{{.State.Status}}", "running", 30*time.Second)
 	c.Assert(err, check.IsNil)
 }
+
+func (s *DockerSuite) TestRestartContainerwithRestartPolicy(c *check.C) {
+	out1, _ := dockerCmd(c, "run", "-d", "--restart=on-failure:3", "busybox", "false")
+	out2, _ := dockerCmd(c, "run", "-d", "--restart=always", "busybox", "false")
+
+	id1 := strings.TrimSpace(string(out1))
+	id2 := strings.TrimSpace(string(out2))
+	err := waitInspect(id1, "{{ .State.Restarting }} {{ .State.Running }}", "false false", 30*time.Second)
+	c.Assert(err, checker.IsNil)
+
+	// TODO: fix racey problem during restart:
+	// https://jenkins.dockerproject.org/job/Docker-PRs-Win2Lin/24665/console
+	// Error response from daemon: Cannot restart container 6655f620d90b390527db23c0a15b3e46d86a58ecec20a5697ab228d860174251: remove /var/run/docker/libcontainerd/6655f620d90b390527db23c0a15b3e46d86a58ecec20a5697ab228d860174251/rootfs: device or resource busy
+	if _, _, err := dockerCmdWithError("restart", id1); err != nil {
+		// if restart met racey problem, try again
+		time.Sleep(500 * time.Millisecond)
+		dockerCmd(c, "restart", id1)
+	}
+	if _, _, err := dockerCmdWithError("restart", id2); err != nil {
+		// if restart met racey problem, try again
+		time.Sleep(500 * time.Millisecond)
+		dockerCmd(c, "restart", id2)
+	}
+
+	dockerCmd(c, "stop", id1)
+	dockerCmd(c, "stop", id2)
+	dockerCmd(c, "start", id1)
+	dockerCmd(c, "start", id2)
+}

libcontainerd/client_linux.go

@@ -134,7 +134,7 @@ func (clnt *client) Create(containerID string, spec Spec, options ...CreateOptio
 	defer clnt.unlock(containerID)
 
 	if ctr, err := clnt.getContainer(containerID); err == nil {
-		if ctr.restarting { // docker doesn't actually call start if restart is on atm, but probably should in the future
+		if ctr.restarting {
 			ctr.restartManager.Cancel()
 			ctr.clean()
 		} else {

libcontainerd/container_linux.go

@@ -124,6 +124,7 @@ func (ctr *container) handleEvent(e *containerd.Event) error {
 			} else if restart {
 				st.State = StateRestart
 				ctr.restarting = true
+				ctr.client.deleteContainer(e.Id)
 				go func() {
 					err := <-wait
 					ctr.restarting = false

restartmanager/restartmanager.go

@@ -51,7 +51,7 @@ func (rm *restartManager) ShouldRestart(exitCode uint32) (bool, chan error, erro
 	}()
 
 	if rm.canceled {
-		return false, nil, nil
+		return false, nil, fmt.Errorf("restartmanager canceled")
 	}
 
 	if rm.active {