Add support for --rollback.

contrib/completions/bash/kubectl

@@ -424,6 +424,7 @@ _kubectl_rolling-update()
     two_word_flags+=("-o")
     flags+=("--output-version=")
     flags+=("--poll-interval=")
+    flags+=("--rollback")
     flags+=("--template=")
     two_word_flags+=("-t")
     flags+=("--timeout=")

docs/design/simple-rolling-update.md

@@ -38,7 +38,7 @@ it is assumed that the rollout is nearly completed, and ```foo-next``` is rename
 ### Aborting a rollout
 Abort is assumed to want to reverse a rollout in progress.
 
-```kubectl rolling-update rc foo [foo-v2] --abort```
+```kubectl rolling-update rc foo [foo-v2] --rollback```
 
 This is really just semantic sugar for:
 

docs/kubectl_rolling-update.md

@@ -45,6 +45,7 @@ $ kubectl rolling-update frontend --image=image:v2
   -o, --output="": Output format. One of: json|yaml|template|templatefile.
       --output-version="": Output the formatted object with the given version (default api-version).
       --poll-interval="3s": Time delay between polling controller status after update. Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h".
+      --rollback=false: If true, this is a request to abort an existing rollout that is partially rolled out. It effectively reverses current and next and runs a rollout
   -t, --template="": Template string or path to template file to use when -o=template or -o=templatefile.  The template format is golang templates [http://golang.org/pkg/text/template/#pkg-overview]
       --timeout="5m0s": Max time to wait for a controller to update before giving up. Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h".
       --update-period="1m0s": Time to wait between updating pods. Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h".
@@ -83,4 +84,4 @@ $ kubectl rolling-update frontend --image=image:v2
 ### SEE ALSO
 * [kubectl](kubectl.md)	 - kubectl controls the Kubernetes cluster manager
 
-###### Auto generated by spf13/cobra at 2015-04-29 15:25:11.031878187 +0000 UTC
+###### Auto generated by spf13/cobra at 2015-05-02 00:22:29.503205238 +0000 UTC

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

@@ -59,6 +59,10 @@ existing controller and overwrite at least one (common) label in its replicaSele
     Time delay between polling controller status after update. Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h".
 
 .PP
+\fB\-\-rollback\fP=false
+    If true, this is a request to abort an existing rollout that is partially rolled out. It effectively reverses current and next and runs a rollout
+
+.PP
 \fB\-t\fP, \fB\-\-template\fP=""
     Template string or path to template file to use when \-o=template or \-o=templatefile.  The template format is golang templates [
 \[la]http://golang.org/pkg/text/template/#pkg-overview\[ra]]

pkg/kubectl/cmd/rollingupdate.go

@@ -82,6 +82,7 @@ func NewCmdRollingUpdate(f *cmdutil.Factory, out io.Writer) *cobra.Command {
 	cmd.Flags().String("image", "", "Image to upgrade the controller to.  Can not be used with --filename/-f")
 	cmd.Flags().String("deployment-label-key", "deployment", "The key to use to differentiate between two different controllers, default 'deployment'.  Only relevant when --image is specified, ignored otherwise")
 	cmd.Flags().Bool("dry-run", false, "If true, print out the changes that would be made, but don't actually make them.")
+	cmd.Flags().Bool("rollback", false, "If true, this is a request to abort an existing rollout that is partially rolled out. It effectively reverses current and next and runs a rollout")
 	cmdutil.AddPrinterFlags(cmd)
 	return cmd
 }
@@ -171,11 +172,16 @@ func RunRollingUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, arg
 
 		if len(newName) > 0 {
 			newRc, err = client.ReplicationControllers(cmdNamespace).Get(newName)
-			if err != nil && !apierrors.IsNotFound(err) {
+			if err != nil {
+				if !apierrors.IsNotFound(err) {
 					return err
+				} else {
+					newRc = nil
 				}
+			} else {
 				fmt.Fprint(out, "Found existing update in progress (%s), resuming.\n", newName)
 			}
+		}
 		if newRc == nil {
 			// load the old RC into the "new" RC
 			if newRc, err = client.ReplicationControllers(cmdNamespace).Get(oldName); err != nil {
@@ -257,7 +263,7 @@ func RunRollingUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, arg
 	if keepOldName {
 		updateCleanupPolicy = kubectl.RenameRollingUpdateCleanupPolicy
 	}
-	err = updater.Update(&kubectl.RollingUpdaterConfig{
+	config := &kubectl.RollingUpdaterConfig{
 		Out:           out,
 		OldRc:         oldRc,
 		NewRc:         newRc,
@@ -265,7 +271,12 @@ func RunRollingUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, arg
 		Interval:      interval,
 		Timeout:       timeout,
 		CleanupPolicy: updateCleanupPolicy,
-	})
+	}
+	if cmdutil.GetFlagBool(cmd, "rollback") {
+		kubectl.AbortRollingUpdate(config)
+		client.ReplicationControllers(config.NewRc.Namespace).Update(config.NewRc)
+	}
+	err = updater.Update(config)
 	if err != nil {
 		return err
 	}

pkg/kubectl/rolling_updater.go

@@ -85,6 +85,24 @@ const (
 	nextControllerAnnotation  = kubectlAnnotationPrefix + "next-controller-id"
 )
 
+func AbortRollingUpdate(c *RollingUpdaterConfig) {
+	// Swap the controllers
+	tmp := c.OldRc
+	c.OldRc = c.NewRc
+	c.NewRc = tmp
+
+	if c.NewRc.Annotations == nil {
+		c.NewRc.Annotations = map[string]string{}
+	}
+	c.NewRc.Annotations[sourceIdAnnotation] = fmt.Sprintf("%s:%s", c.OldRc.Name, c.OldRc.UID)
+	desiredSize, found := c.OldRc.Annotations[desiredReplicasAnnotation]
+	if found {
+		fmt.Printf("Found desired replicas.")
+		c.NewRc.Annotations[desiredReplicasAnnotation] = desiredSize
+	}
+	c.CleanupPolicy = DeleteRollingUpdateCleanupPolicy
+}
+
 func GetNextControllerAnnotation(rc *api.ReplicationController) (string, bool) {
 	res, found := rc.Annotations[nextControllerAnnotation]
 	return res, found
@@ -237,7 +255,7 @@ func (r *RollingUpdater) getExistingNewRc(sourceId, name string) (rc *api.Replic
 		source := annotations[sourceIdAnnotation]
 		_, ok := annotations[desiredReplicasAnnotation]
 		if source != sourceId || !ok {
-			err = fmt.Errorf("Missing/unexpected annotations for controller %s: %s", name, annotations)
+			err = fmt.Errorf("Missing/unexpected annotations for controller %s, expected %s : %s", name, sourceId, annotations)
 		}
 		return
 	}