rename a existing container

Closes #3036

Signed-off-by: Srini Brahmaroutu <srbrahma@us.ibm.com>
Upstream-commit: 21a809d9ae0ef8392f37c9262dca93ff31966e22
Component: engine

components/engine/daemon/daemon.go

@@ -113,6 +113,7 @@ func (daemon *Daemon) Install(eng *engine.Engine) error {
 		"commit":            daemon.ContainerCommit,
 		"container_changes": daemon.ContainerChanges,
 		"container_copy":    daemon.ContainerCopy,
+		"container_rename":  daemon.ContainerRename,
 		"container_inspect": daemon.ContainerInspect,
 		"containers":        daemon.Containers,
 		"create":            daemon.ContainerCreate,

components/engine/daemon/rename.go

@@ -0,0 +1,30 @@
+package daemon
+
+import (
+	"github.com/docker/docker/engine"
+)
+
+func (daemon *Daemon) ContainerRename(job *engine.Job) engine.Status {
+	if len(job.Args) != 2 {
+		return job.Errorf("usage: %s OLD_NAME NEW_NAME", job.Name)
+	}
+	old_name := job.Args[0]
+	new_name := job.Args[1]
+
+	container := daemon.Get(old_name)
+	if container == nil {
+		return job.Errorf("No such container: %s", old_name)
+	}
+
+	container.Lock()
+	defer container.Unlock()
+	if err := daemon.containerGraph.Delete(container.Name); err != nil {
+		return job.Errorf("Failed to delete container %q: %v", old_name, err)
+	}
+	if _, err := daemon.reserveName(container.ID, new_name); err != nil {
+		return job.Errorf("Error when allocating new name: %s", err)
+	}
+	container.Name = new_name
+
+	return engine.StatusOK
+}