Add replication controller renaming as a cleanup option.

docs/kubectl_rolling-update.md

@@ -12,7 +12,7 @@ new PodTemplate. The new-controller.json must specify the same namespace as the
 existing controller and overwrite at least one (common) label in its replicaSelector.
 
 ```
-kubectl rolling-update OLD_CONTROLLER_NAME -f NEW_CONTROLLER_SPEC
+kubectl rolling-update OLD_CONTROLLER_NAME ([NEW_CONTROLLER_NAME] --image=NEW_CONTAINER_IMAGE | -f NEW_CONTROLLER_SPEC)
 ```
 
 ### Examples
@@ -24,9 +24,13 @@ $ kubectl rolling-update frontend-v1 -f frontend-v2.json
 // Update pods of frontend-v1 using JSON data passed into stdin.
 $ cat frontend-v2.json | kubectl rolling-update frontend-v1 -f -
 
-// Update the pods of frontend-v1 to frontend-v2 by just changing the image
+// Update the pods of frontend-v1 to frontend-v2 by just changing the image, and switching the
+// name of the replication controller.
 $ kubectl rolling-update frontend-v1 frontend-v2 --image=image:v2
 
+// Update the pods of frontend by just changing the image, and keeping the old name
+$ kubectl rolling-update frontend --image=image:v2
+
 ```
 
 ### Options
@@ -79,4 +83,4 @@ $ kubectl rolling-update frontend-v1 frontend-v2 --image=image:v2
 ### SEE ALSO
 * [kubectl](kubectl.md)	 - kubectl controls the Kubernetes cluster manager
 
-###### Auto generated by spf13/cobra at 2015-04-27 22:01:46.525154396 +0000 UTC
+###### Auto generated by spf13/cobra at 2015-04-27 22:44:36.84341428 +0000 UTC

docs/man/man1/kubectl-rolling-update.1

@@ -185,9 +185,13 @@ $ kubectl rolling\-update frontend\-v1 \-f frontend\-v2.json
 // Update pods of frontend\-v1 using JSON data passed into stdin.
 $ cat frontend\-v2.json | kubectl rolling\-update frontend\-v1 \-f \-
 
-// Update the pods of frontend\-v1 to frontend\-v2 by just changing the image
+// Update the pods of frontend\-v1 to frontend\-v2 by just changing the image, and switching the
+// name of the replication controller.
 $ kubectl rolling\-update frontend\-v1 frontend\-v2 \-\-image=image:v2
 
+// Update the pods of frontend by just changing the image, and keeping the old name
+$ kubectl rolling\-update frontend \-\-image=image:v2
+
 
 .fi
 .RE

pkg/kubectl/cmd/rollingupdate.go

@@ -51,14 +51,18 @@ $ kubectl rolling-update frontend-v1 -f frontend-v2.json
 // Update pods of frontend-v1 using JSON data passed into stdin.
 $ cat frontend-v2.json | kubectl rolling-update frontend-v1 -f -
 
-// Update the pods of frontend-v1 to frontend-v2 by just changing the image
+// Update the pods of frontend-v1 to frontend-v2 by just changing the image, and switching the
+// name of the replication controller.
 $ kubectl rolling-update frontend-v1 frontend-v2 --image=image:v2
+
+// Update the pods of frontend by just changing the image, and keeping the old name
+$ kubectl rolling-update frontend --image=image:v2
 `
 )
 
 func NewCmdRollingUpdate(f *cmdutil.Factory, out io.Writer) *cobra.Command {
 	cmd := &cobra.Command{
-		Use: "rolling-update OLD_CONTROLLER_NAME -f NEW_CONTROLLER_SPEC",
+		Use: "rolling-update OLD_CONTROLLER_NAME ([NEW_CONTROLLER_NAME] --image=NEW_CONTAINER_IMAGE | -f NEW_CONTROLLER_SPEC)",
 		// rollingupdate is deprecated.
 		Aliases: []string{"rollingupdate"},
 		Short:   "Perform a rolling update of the given ReplicationController.",
@@ -94,9 +98,6 @@ func validateArguments(cmd *cobra.Command, args []string) (deploymentKey, filena
 	if len(filename) != 0 && len(image) != 0 {
 		return "", "", "", "", cmdutil.UsageError(cmd, "--filename and --image can not both be specified")
 	}
-	if len(image) > 0 && len(args) < 2 {
-		return "", "", "", "", cmdutil.UsageError(cmd, "You must specify a name for your new controller")
-	}
 	if len(args) < 1 {
 		return "", "", "", "", cmdutil.UsageError(cmd, "Must specify the controller to update")
 	}
@@ -133,6 +134,8 @@ func RunRollingUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, arg
 		return err
 	}
 
+	keepOldName := false
+
 	mapper, typer := f.Object()
 	var newRc *api.ReplicationController
 
@@ -152,7 +155,6 @@ func RunRollingUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, arg
 		}
 	}
 	if len(image) != 0 {
-		newName := args[1]
 		var err error
 		// load the old RC into the "new" RC
 		if newRc, err = client.ReplicationControllers(cmdNamespace).Get(oldName); err != nil {
@@ -172,10 +174,19 @@ func RunRollingUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, arg
 		if err != nil {
 			return err
 		}
+
+		var newName string
+		if len(args) >= 2 {
+			newName = args[1]
+		} else {
+			keepOldName = true
+			newName = fmt.Sprintf("%s-%s", newRc.Name, newHash)
+		}
 		newRc.Name = newName
 
 		newRc.Spec.Selector[deploymentKey] = newHash
 		newRc.Spec.Template.Labels[deploymentKey] = newHash
+		// Clear resource version after hashing so that identical updates get different hashes.
 		newRc.ResourceVersion = ""
 
 		if _, found := oldRc.Spec.Selector[deploymentKey]; !found {
@@ -219,6 +230,10 @@ func RunRollingUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, arg
 		fmt.Fprintf(out, "Rolling from:\n%s\nTo:\n%s\n", string(oldRcData.Bytes()), string(newRcData.Bytes()))
 		return nil
 	}
+	updateCleanupPolicy := kubectl.DeleteRollingUpdateCleanupPolicy
+	if keepOldName {
+		updateCleanupPolicy = kubectl.RenameRollingUpdateCleanupPolicy
+	}
 	err = updater.Update(&kubectl.RollingUpdaterConfig{
 		Out:           out,
 		OldRc:         oldRc,
@@ -226,13 +241,17 @@ func RunRollingUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, arg
 		UpdatePeriod:  period,
 		Interval:      interval,
 		Timeout:       timeout,
-		CleanupPolicy: kubectl.DeleteRollingUpdateCleanupPolicy,
+		CleanupPolicy: updateCleanupPolicy,
 	})
 	if err != nil {
 		return err
 	}
 
-	fmt.Fprintf(out, "%s\n", newName)
+	if keepOldName {
+		fmt.Fprintf(out, "%s\n", oldName)
+	} else {
+		fmt.Fprintf(out, "%s\n", newName)
+	}
 	return nil
 }
 

pkg/kubectl/cmd/rollingupdate_test.go

@@ -59,9 +59,8 @@ func TestValidateArgs(t *testing.T) {
 			flags: map[string]string{
 				"image": "foo:v2",
 			},
-			args:      []string{"foo"},
-			expectErr: true,
-			testName:  "missing second image name",
+			args:     []string{"foo"},
+			testName: "missing second image name",
 		},
 		{
 			flags: map[string]string{

pkg/kubectl/rolling_updater.go

@@ -66,6 +66,9 @@ const (
 	DeleteRollingUpdateCleanupPolicy RollingUpdaterCleanupPolicy = "Delete"
 	// PreserveRollingUpdateCleanupPolicy means keep the old controller.
 	PreserveRollingUpdateCleanupPolicy RollingUpdaterCleanupPolicy = "Preserve"
+	// RenameRollingUpdateCleanupPolicy means delete the old controller, and rename
+	// the new controller to the name of the old controller.
+	RenameRollingUpdateCleanupPolicy RollingUpdaterCleanupPolicy = "Rename"
 )
 
 // NewRollingUpdater creates a RollingUpdater from a client
@@ -199,6 +202,14 @@ func (r *RollingUpdater) Update(config *RollingUpdaterConfig) error {
 		// delete old rc
 		fmt.Fprintf(out, "Update succeeded. Deleting %s\n", oldName)
 		return r.c.DeleteReplicationController(r.ns, oldName)
+	case RenameRollingUpdateCleanupPolicy:
+		// delete old rc
+		fmt.Fprintf(out, "Update succeeded. Deleting old controller: %s\n", oldName)
+		if err := r.c.DeleteReplicationController(r.ns, oldName); err != nil {
+			return err
+		}
+		fmt.Fprintf(out, "Renaming %s to %s\n", newRc.Name, oldName)
+		return r.rename(newRc, oldName)
 	case PreserveRollingUpdateCleanupPolicy:
 		return nil
 	default:
@@ -243,6 +254,18 @@ func (r *RollingUpdater) updateAndWait(rc *api.ReplicationController, interval,
 	return r.c.GetReplicationController(r.ns, rc.ObjectMeta.Name)
 }
 
+func (r *RollingUpdater) rename(rc *api.ReplicationController, newName string) error {
+	oldName := rc.Name
+	rc.Name = newName
+	rc.ResourceVersion = ""
+
+	_, err := r.c.CreateReplicationController(rc.Namespace, rc)
+	if err != nil {
+		return err
+	}
+	return r.c.DeleteReplicationController(rc.Namespace, oldName)
+}
+
 // RollingUpdaterClient abstracts access to ReplicationControllers.
 type RollingUpdaterClient interface {
 	GetReplicationController(namespace, name string) (*api.ReplicationController, error)