kubectl rolling-update support for same image

contrib/completions/bash/kubectl

@@ -1668,6 +1668,7 @@ _kubectl_rolling-update()
     flags_with_completion+=("-f")
     flags_completion+=("__handle_filename_extension_flag json|yaml|yml")
     flags+=("--image=")
+    flags+=("--image-pull-policy=")
     flags+=("--include-extended-apis")
     flags+=("--no-headers")
     flags+=("--output=")

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

@@ -43,6 +43,10 @@ existing replication controller and overwrite at least one (common) label in its
     Image to use for upgrading the replication controller. Must be distinct from the existing image (either new image or new image tag).  Can not be used with \-\-filename/\-f
 
 .PP
+\fB\-\-image\-pull\-policy\fP=""
+    Explicit policy for when to pull container images. Required when \-\-image is same as existing image, ignored otherwise.
+
+.PP
 \fB\-\-include\-extended\-apis\fP=true
     If true, include definitions of new APIs via calls to the API server. [default true]
 

docs/user-guide/kubectl/kubectl_rolling-update.md

@@ -78,6 +78,7 @@ kubectl rolling-update frontend-v1 frontend-v2 --rollback
       --dry-run[=false]: If true, print out the changes that would be made, but don't actually make them.
   -f, --filename=[]: Filename or URL to file to use to create the new replication controller.
       --image="": Image to use for upgrading the replication controller. Must be distinct from the existing image (either new image or new image tag).  Can not be used with --filename/-f
+      --image-pull-policy="": Explicit policy for when to pull container images. Required when --image is same as existing image, ignored otherwise.
       --include-extended-apis[=true]: If true, include definitions of new APIs via calls to the API server. [default true]
       --no-headers[=false]: When using the default output, don't print headers.
   -o, --output="": Output format. One of: json|yaml|wide|name|go-template=...|go-template-file=...|jsonpath=...|jsonpath-file=... See golang template [http://golang.org/pkg/text/template/#pkg-overview] and jsonpath template [http://releases.k8s.io/HEAD/docs/user-guide/jsonpath.md].
@@ -126,7 +127,7 @@ kubectl rolling-update frontend-v1 frontend-v2 --rollback
 
 * [kubectl](kubectl.md)	 - kubectl controls the Kubernetes cluster manager
 
-###### Auto generated by spf13/cobra on 5-Apr-2016
+###### Auto generated by spf13/cobra on 21-Apr-2016
 
 <!-- BEGIN MUNGE: GENERATED_ANALYTICS -->
 [![Analytics](https://kubernetes-site.appspot.com/UA-36037335-10/GitHub/docs/user-guide/kubectl/kubectl_rolling-update.md?pixel)]()

docs/yaml/kubectl/kubectl_rolling-update.yaml

@@ -26,6 +26,9 @@ options:
 - name: image
   usage: |
     Image to use for upgrading the replication controller. Must be distinct from the existing image (either new image or new image tag).  Can not be used with --filename/-f
+- name: image-pull-policy
+  usage: |
+    Explicit policy for when to pull container images. Required when --image is same as existing image, ignored otherwise.
 - name: include-extended-apis
   default_value: "true"
   usage: |

hack/verify-flags/known-flags.txt

@@ -164,6 +164,7 @@ ignore-daemonsets
 ignore-not-found
 image-gc-high-threshold
 image-gc-low-threshold
+image-pull-policy
 include-extended-apis
 input-dirs
 insecure-bind-address

pkg/kubectl/cmd/rollingupdate.go

@@ -97,6 +97,7 @@ func NewCmdRollingUpdate(f *cmdutil.Factory, out io.Writer) *cobra.Command {
 	cmd.MarkFlagRequired("image")
 	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().String("container", "", "Container name which will have its image upgraded. Only relevant when --image is specified, ignored otherwise. Required when using --image on a multi-container pod")
+	cmd.Flags().String("image-pull-policy", "", "Explicit policy for when to pull container images. Required when --image is same as existing image, 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.AddValidateFlags(cmd)
@@ -150,6 +151,7 @@ func RunRollingUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, arg
 	deploymentKey := cmdutil.GetFlagString(cmd, "deployment-label-key")
 	filename := ""
 	image := cmdutil.GetFlagString(cmd, "image")
+	pullPolicy := cmdutil.GetFlagString(cmd, "image-pull-policy")
 	oldName := args[0]
 	rollback := cmdutil.GetFlagBool(cmd, "rollback")
 	period := cmdutil.GetFlagDuration(cmd, "update-period")
@@ -233,8 +235,8 @@ func RunRollingUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, arg
 		}
 	}
 	// If the --image option is specified, we need to create a new rc with at least one different selector
-	// than the old rc. This selector is the hash of the rc, which will differ because the new rc has a
-	// different image.
+	// than the old rc. This selector is the hash of the rc, with a suffix to provide uniqueness for
+	// same-image updates.
 	if len(image) != 0 {
 		codec := api.Codecs.LegacyCodec(client.APIVersion())
 		keepOldName = len(args) == 1
@@ -248,10 +250,21 @@ func RunRollingUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, arg
 			}
 			fmt.Fprintf(out, "Found existing update in progress (%s), resuming.\n", newRc.Name)
 		} else {
+			config := &kubectl.NewControllerConfig{
+				Namespace:     cmdNamespace,
+				OldName:       oldName,
+				NewName:       newName,
+				Image:         image,
+				Container:     container,
+				DeploymentKey: deploymentKey,
+			}
 			if oldRc.Spec.Template.Spec.Containers[0].Image == image {
-				return cmdutil.UsageError(cmd, "Specified --image must be distinct from existing container image")
+				if len(pullPolicy) == 0 {
+					return cmdutil.UsageError(cmd, "--image-pull-policy (Always|Never|IfNotPresent) must be provided when --image is the same as existing container image")
+				}
+				config.PullPolicy = api.PullPolicy(pullPolicy)
 			}
-			newRc, err = kubectl.CreateNewControllerFromCurrentController(client, codec, cmdNamespace, oldName, newName, image, container, deploymentKey)
+			newRc, err = kubectl.CreateNewControllerFromCurrentController(client, codec, config)
 			if err != nil {
 				return err
 			}
@@ -262,6 +275,8 @@ func RunRollingUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, arg
 		if err != nil {
 			return err
 		}
+		// If new image is same as old, the hash may not be distinct, so add a suffix.
+		oldHash += "-orig"
 		oldRc, err = kubectl.UpdateExistingReplicationController(client, oldRc, cmdNamespace, newRc.Name, deploymentKey, oldHash, out)
 		if err != nil {
 			return err

pkg/kubectl/rolling_updater.go

@@ -504,19 +504,28 @@ func LoadExistingNextReplicationController(c client.ReplicationControllersNamesp
 	return newRc, err
 }
 
-func CreateNewControllerFromCurrentController(c client.Interface, codec runtime.Codec, namespace, oldName, newName, image, container, deploymentKey string) (*api.ReplicationController, error) {
+type NewControllerConfig struct {
+	Namespace        string
+	OldName, NewName string
+	Image            string
+	Container        string
+	DeploymentKey    string
+	PullPolicy       api.PullPolicy
+}
+
+func CreateNewControllerFromCurrentController(c client.Interface, codec runtime.Codec, cfg *NewControllerConfig) (*api.ReplicationController, error) {
 	containerIndex := 0
 	// load the old RC into the "new" RC
-	newRc, err := c.ReplicationControllers(namespace).Get(oldName)
+	newRc, err := c.ReplicationControllers(cfg.Namespace).Get(cfg.OldName)
 	if err != nil {
 		return nil, err
 	}
 
-	if len(container) != 0 {
+	if len(cfg.Container) != 0 {
 		containerFound := false
 
 		for i, c := range newRc.Spec.Template.Spec.Containers {
-			if c.Name == container {
+			if c.Name == cfg.Container {
 				containerIndex = i
 				containerFound = true
 				break
@@ -524,31 +533,34 @@ func CreateNewControllerFromCurrentController(c client.Interface, codec runtime.
 		}
 
 		if !containerFound {
-			return nil, fmt.Errorf("container %s not found in pod", container)
+			return nil, fmt.Errorf("container %s not found in pod", cfg.Container)
 		}
 	}
 
-	if len(newRc.Spec.Template.Spec.Containers) > 1 && len(container) == 0 {
+	if len(newRc.Spec.Template.Spec.Containers) > 1 && len(cfg.Container) == 0 {
 		return nil, goerrors.New("Must specify container to update when updating a multi-container pod")
 	}
 
 	if len(newRc.Spec.Template.Spec.Containers) == 0 {
 		return nil, goerrors.New(fmt.Sprintf("Pod has no containers! (%v)", newRc))
 	}
-	newRc.Spec.Template.Spec.Containers[containerIndex].Image = image
+	newRc.Spec.Template.Spec.Containers[containerIndex].Image = cfg.Image
+	if len(cfg.PullPolicy) != 0 {
+		newRc.Spec.Template.Spec.Containers[containerIndex].ImagePullPolicy = cfg.PullPolicy
+	}
 
 	newHash, err := api.HashObject(newRc, codec)
 	if err != nil {
 		return nil, err
 	}
 
-	if len(newName) == 0 {
-		newName = fmt.Sprintf("%s-%s", newRc.Name, newHash)
+	if len(cfg.NewName) == 0 {
+		cfg.NewName = fmt.Sprintf("%s-%s", newRc.Name, newHash)
 	}
-	newRc.Name = newName
+	newRc.Name = cfg.NewName
 
-	newRc.Spec.Selector[deploymentKey] = newHash
-	newRc.Spec.Template.Labels[deploymentKey] = newHash
+	newRc.Spec.Selector[cfg.DeploymentKey] = newHash
+	newRc.Spec.Template.Labels[cfg.DeploymentKey] = newHash
 	// Clear resource version after hashing so that identical updates get different hashes.
 	newRc.ResourceVersion = ""
 	return newRc, nil

pkg/kubectl/rolling_updater_test.go

@@ -1090,12 +1090,19 @@ func TestRollingUpdater_multipleContainersInPod(t *testing.T) {
 		test.newRc.Spec.Template.Labels[test.deploymentKey] = deploymentHash
 		test.newRc.Name = fmt.Sprintf("%s-%s", test.newRc.Name, deploymentHash)
 
-		updatedRc, err := CreateNewControllerFromCurrentController(fake, codec, "", test.oldRc.ObjectMeta.Name, test.newRc.ObjectMeta.Name, test.image, test.container, test.deploymentKey)
+		config := &NewControllerConfig{
+			OldName:       test.oldRc.ObjectMeta.Name,
+			NewName:       test.newRc.ObjectMeta.Name,
+			Image:         test.image,
+			Container:     test.container,
+			DeploymentKey: test.deploymentKey,
+		}
+		updatedRc, err := CreateNewControllerFromCurrentController(fake, codec, config)
 		if err != nil {
 			t.Errorf("unexpected error: %v", err)
 		}
 		if !reflect.DeepEqual(updatedRc, test.newRc) {
-			t.Errorf("expected:\n%v\ngot:\n%v\n", test.newRc, updatedRc)
+			t.Errorf("expected:\n%#v\ngot:\n%#v\n", test.newRc, updatedRc)
 		}
 	}
 }