Implemet docker update command

It's used for updating properties of one or more containers, we only
support resource configs for now. It can be extended in the future.

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>

api/server/router/container/backend.go

@@ -42,6 +42,7 @@ type stateBackend interface {
 	ContainerStart(name string, hostConfig *container.HostConfig) error
 	ContainerStop(name string, seconds int) error
 	ContainerUnpause(name string) error
+	ContainerUpdate(name string, hostConfig *container.HostConfig) ([]string, error)
 	ContainerWait(name string, timeout time.Duration) (int, error)
 	Exists(id string) bool
 	IsPaused(id string) bool

api/server/router/container/container.go

@@ -57,6 +57,7 @@ func (r *containerRouter) initRoutes() {
 		local.NewPostRoute("/exec/{name:.*}/start", r.postContainerExecStart),
 		local.NewPostRoute("/exec/{name:.*}/resize", r.postContainerExecResize),
 		local.NewPostRoute("/containers/{name:.*}/rename", r.postContainerRename),
+		local.NewPostRoute("/containers/{name:.*}/update", r.postContainerUpdate),
 		// PUT
 		local.NewPutRoute("/containers/{name:.*}/archive", r.putContainersArchive),
 		// DELETE

api/server/router/container/container_routes.go

@@ -323,6 +323,30 @@ func (s *containerRouter) postContainerRename(ctx context.Context, w http.Respon
 	return nil
 }
 
+func (s *containerRouter) postContainerUpdate(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
+	if err := httputils.ParseForm(r); err != nil {
+		return err
+	}
+	if err := httputils.CheckForJSON(r); err != nil {
+		return err
+	}
+
+	_, hostConfig, err := runconfig.DecodeContainerConfig(r.Body)
+	if err != nil {
+		return err
+	}
+
+	name := vars["name"]
+	warnings, err := s.backend.ContainerUpdate(name, hostConfig)
+	if err != nil {
+		return err
+	}
+
+	return httputils.WriteJSON(w, http.StatusOK, &types.ContainerUpdateResponse{
+		Warnings: warnings,
+	})
+}
+
 func (s *containerRouter) postContainersCreate(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
 	if err := httputils.ParseForm(r); err != nil {
 		return err