Add kubectl rollout history

.generated_docs

@@ -43,6 +43,7 @@ docs/man/man1/kubectl-port-forward.1
 docs/man/man1/kubectl-proxy.1
 docs/man/man1/kubectl-replace.1
 docs/man/man1/kubectl-rolling-update.1
+docs/man/man1/kubectl-rollout-history.1
 docs/man/man1/kubectl-rollout.1
 docs/man/man1/kubectl-run.1
 docs/man/man1/kubectl-scale.1
@@ -90,6 +91,7 @@ docs/user-guide/kubectl/kubectl_proxy.md
 docs/user-guide/kubectl/kubectl_replace.md
 docs/user-guide/kubectl/kubectl_rolling-update.md
 docs/user-guide/kubectl/kubectl_rollout.md
+docs/user-guide/kubectl/kubectl_rollout_history.md
 docs/user-guide/kubectl/kubectl_run.md
 docs/user-guide/kubectl/kubectl_scale.md
 docs/user-guide/kubectl/kubectl_uncordon.md

contrib/completions/bash/kubectl

@@ -1656,10 +1656,57 @@ _kubectl_autoscale()
     must_have_one_noun=()
 }
 
+_kubectl_rollout_history()
+{
+    last_command="kubectl_rollout_history"
+    commands=()
+
+    flags=()
+    two_word_flags=()
+    flags_with_completion=()
+    flags_completion=()
+
+    flags+=("--filename=")
+    flags_with_completion+=("--filename")
+    flags_completion+=("__handle_filename_extension_flag json|yaml|yml")
+    two_word_flags+=("-f")
+    flags_with_completion+=("-f")
+    flags_completion+=("__handle_filename_extension_flag json|yaml|yml")
+    flags+=("--revision=")
+    flags+=("--alsologtostderr")
+    flags+=("--api-version=")
+    flags+=("--certificate-authority=")
+    flags+=("--client-certificate=")
+    flags+=("--client-key=")
+    flags+=("--cluster=")
+    flags+=("--context=")
+    flags+=("--insecure-skip-tls-verify")
+    flags+=("--kubeconfig=")
+    flags+=("--log-backtrace-at=")
+    flags+=("--log-dir=")
+    flags+=("--log-flush-frequency=")
+    flags+=("--logtostderr")
+    flags+=("--match-server-version")
+    flags+=("--namespace=")
+    flags+=("--password=")
+    flags+=("--server=")
+    two_word_flags+=("-s")
+    flags+=("--stderrthreshold=")
+    flags+=("--token=")
+    flags+=("--user=")
+    flags+=("--username=")
+    flags+=("--v=")
+    flags+=("--vmodule=")
+
+    must_have_one_flag=()
+    must_have_one_noun=()
+}
+
 _kubectl_rollout()
 {
     last_command="kubectl_rollout"
     commands=()
+    commands+=("history")
 
     flags=()
     two_word_flags=()

docs/man/man1/kubectl-rollout-history.1

@@ -0,0 +1,142 @@
+.TH "KUBERNETES" "1" " kubernetes User Manuals" "Eric Paris" "Jan 2015"  ""
+
+
+.SH NAME
+.PP
+kubectl rollout history \- view rollout history
+
+
+.SH SYNOPSIS
+.PP
+\fBkubectl rollout history\fP [OPTIONS]
+
+
+.SH DESCRIPTION
+.PP
+view previous rollout revisions and configurations.
+
+
+.SH OPTIONS
+.PP
+\fB\-f\fP, \fB\-\-filename\fP=[]
+    Filename, directory, or URL to a file identifying the resource to get from a server.
+
+.PP
+\fB\-\-revision\fP=0
+    See the details, including podTemplate of the revision specified
+
+
+.SH OPTIONS INHERITED FROM PARENT COMMANDS
+.PP
+\fB\-\-alsologtostderr\fP=false
+    log to standard error as well as files
+
+.PP
+\fB\-\-api\-version\fP=""
+    The API version to use when talking to the server
+
+.PP
+\fB\-\-certificate\-authority\fP=""
+    Path to a cert. file for the certificate authority.
+
+.PP
+\fB\-\-client\-certificate\fP=""
+    Path to a client certificate file for TLS.
+
+.PP
+\fB\-\-client\-key\fP=""
+    Path to a client key file for TLS.
+
+.PP
+\fB\-\-cluster\fP=""
+    The name of the kubeconfig cluster to use
+
+.PP
+\fB\-\-context\fP=""
+    The name of the kubeconfig context to use
+
+.PP
+\fB\-\-insecure\-skip\-tls\-verify\fP=false
+    If true, the server's certificate will not be checked for validity. This will make your HTTPS connections insecure.
+
+.PP
+\fB\-\-kubeconfig\fP=""
+    Path to the kubeconfig file to use for CLI requests.
+
+.PP
+\fB\-\-log\-backtrace\-at\fP=:0
+    when logging hits line file:N, emit a stack trace
+
+.PP
+\fB\-\-log\-dir\fP=""
+    If non\-empty, write log files in this directory
+
+.PP
+\fB\-\-log\-flush\-frequency\fP=5s
+    Maximum number of seconds between log flushes
+
+.PP
+\fB\-\-logtostderr\fP=true
+    log to standard error instead of files
+
+.PP
+\fB\-\-match\-server\-version\fP=false
+    Require server version to match client version
+
+.PP
+\fB\-\-namespace\fP=""
+    If present, the namespace scope for this CLI request.
+
+.PP
+\fB\-\-password\fP=""
+    Password for basic authentication to the API server.
+
+.PP
+\fB\-s\fP, \fB\-\-server\fP=""
+    The address and port of the Kubernetes API server
+
+.PP
+\fB\-\-stderrthreshold\fP=2
+    logs at or above this threshold go to stderr
+
+.PP
+\fB\-\-token\fP=""
+    Bearer token for authentication to the API server.
+
+.PP
+\fB\-\-user\fP=""
+    The name of the kubeconfig user to use
+
+.PP
+\fB\-\-username\fP=""
+    Username for basic authentication to the API server.
+
+.PP
+\fB\-\-v\fP=0
+    log level for V logs
+
+.PP
+\fB\-\-vmodule\fP=
+    comma\-separated list of pattern=N settings for file\-filtered logging
+
+
+.SH EXAMPLE
+.PP
+.RS
+
+.nf
+# View the rollout history of a deployment
+$ kubectl rollout history deployment/abc
+
+.fi
+.RE
+
+
+.SH SEE ALSO
+.PP
+\fBkubectl\-rollout(1)\fP,
+
+
+.SH HISTORY
+.PP
+January 2015, Originally compiled by Eric Paris (eparis at redhat dot com) based on the kubernetes source material, but hopefully they have been automatically generated since!

docs/man/man1/kubectl-rollout.1

@@ -112,7 +112,7 @@ rollout manages a deployment using subcommands
 
 .SH SEE ALSO
 .PP
-\fBkubectl(1)\fP,
+\fBkubectl(1)\fP, \fBkubectl\-rollout\-history(1)\fP,
 
 
 .SH HISTORY

docs/user-guide/kubectl/kubectl_rollout.md

@@ -71,6 +71,7 @@ kubectl rollout SUBCOMMAND
 ### SEE ALSO
 
 * [kubectl](kubectl.md)	 - kubectl controls the Kubernetes cluster manager
+* [kubectl rollout history](kubectl_rollout_history.md)	 - view rollout history
 
 ###### Auto generated by spf13/cobra on 20-Jan-2016
 

docs/user-guide/kubectl/kubectl_rollout_history.md

@@ -0,0 +1,93 @@
+<!-- BEGIN MUNGE: UNVERSIONED_WARNING -->
+
+<!-- BEGIN STRIP_FOR_RELEASE -->
+
+<img src="http://kubernetes.io/img/warning.png" alt="WARNING"
+     width="25" height="25">
+<img src="http://kubernetes.io/img/warning.png" alt="WARNING"
+     width="25" height="25">
+<img src="http://kubernetes.io/img/warning.png" alt="WARNING"
+     width="25" height="25">
+<img src="http://kubernetes.io/img/warning.png" alt="WARNING"
+     width="25" height="25">
+<img src="http://kubernetes.io/img/warning.png" alt="WARNING"
+     width="25" height="25">
+
+<h2>PLEASE NOTE: This document applies to the HEAD of the source tree</h2>
+
+If you are using a released version of Kubernetes, you should
+refer to the docs that go with that version.
+
+Documentation for other releases can be found at
+[releases.k8s.io](http://releases.k8s.io).
+</strong>
+--
+
+<!-- END STRIP_FOR_RELEASE -->
+
+<!-- END MUNGE: UNVERSIONED_WARNING -->
+
+## kubectl rollout history
+
+view rollout history
+
+### Synopsis
+
+
+view previous rollout revisions and configurations.
+
+```
+kubectl rollout history (TYPE NAME | TYPE/NAME) [flags]
+```
+
+### Examples
+
+```
+# View the rollout history of a deployment
+$ kubectl rollout history deployment/abc
+```
+
+### Options
+
+```
+  -f, --filename=[]: Filename, directory, or URL to a file identifying the resource to get from a server.
+      --revision=0: See the details, including podTemplate of the revision specified
+```
+
+### Options inherited from parent commands
+
+```
+      --alsologtostderr[=false]: log to standard error as well as files
+      --api-version="": The API version to use when talking to the server
+      --certificate-authority="": Path to a cert. file for the certificate authority.
+      --client-certificate="": Path to a client certificate file for TLS.
+      --client-key="": Path to a client key file for TLS.
+      --cluster="": The name of the kubeconfig cluster to use
+      --context="": The name of the kubeconfig context to use
+      --insecure-skip-tls-verify[=false]: If true, the server's certificate will not be checked for validity. This will make your HTTPS connections insecure.
+      --kubeconfig="": Path to the kubeconfig file to use for CLI requests.
+      --log-backtrace-at=:0: when logging hits line file:N, emit a stack trace
+      --log-dir="": If non-empty, write log files in this directory
+      --log-flush-frequency=5s: Maximum number of seconds between log flushes
+      --logtostderr[=true]: log to standard error instead of files
+      --match-server-version[=false]: Require server version to match client version
+      --namespace="": If present, the namespace scope for this CLI request.
+      --password="": Password for basic authentication to the API server.
+  -s, --server="": The address and port of the Kubernetes API server
+      --stderrthreshold=2: logs at or above this threshold go to stderr
+      --token="": Bearer token for authentication to the API server.
+      --user="": The name of the kubeconfig user to use
+      --username="": Username for basic authentication to the API server.
+      --v=0: log level for V logs
+      --vmodule=: comma-separated list of pattern=N settings for file-filtered logging
+```
+
+### SEE ALSO
+
+* [kubectl rollout](kubectl_rollout.md)	 - rollout manages a deployment
+
+###### Auto generated by spf13/cobra on 29-Jan-2016
+
+<!-- BEGIN MUNGE: GENERATED_ANALYTICS -->
+[![Analytics](https://kubernetes-site.appspot.com/UA-36037335-10/GitHub/docs/user-guide/kubectl/kubectl_rollout_history.md?pixel)]()
+<!-- END MUNGE: GENERATED_ANALYTICS -->

pkg/controller/deployment/deployment_controller.go

@@ -451,7 +451,7 @@ func (dc *DeploymentController) rollback(deployment *extensions.Deployment, toRe
 		}
 	}
 	for _, rc := range allRCs {
-		v, err := revision(rc)
+		v, err := deploymentutil.Revision(rc)
 		if err != nil {
 			glog.V(4).Infof("Unable to extract revision from deployment's rc %q: %v", rc.Name, err)
 			continue
@@ -617,18 +617,10 @@ func (dc *DeploymentController) getNewRCAndAllOldRCs(deployment extensions.Deplo
 	return dc.getNewRCAndMaybeFilteredOldRCs(deployment, false)
 }
 
-func revision(rc *api.ReplicationController) (int64, error) {
-	v, ok := rc.Annotations[deploymentutil.RevisionAnnotation]
-	if !ok {
-		return 0, nil
-	}
-	return strconv.ParseInt(v, 10, 64)
-}
-
 func maxRevision(allRCs []*api.ReplicationController) int64 {
 	max := int64(0)
 	for _, rc := range allRCs {
-		if v, err := revision(rc); err != nil {
+		if v, err := deploymentutil.Revision(rc); err != nil {
 			// Skip the RCs when it failed to parse their revision information
 			glog.V(4).Infof("Error: %v. Couldn't parse revision for rc %#v, deployment controller will skip it when reconciling revisions.", err, rc)
 		} else if v > max {
@@ -642,7 +634,7 @@ func maxRevision(allRCs []*api.ReplicationController) int64 {
 func lastRevision(allRCs []*api.ReplicationController) int64 {
 	max, secMax := int64(0), int64(0)
 	for _, rc := range allRCs {
-		if v, err := revision(rc); err != nil {
+		if v, err := deploymentutil.Revision(rc); err != nil {
 			// Skip the RCs when it failed to parse their revision information
 			glog.V(4).Infof("Error: %v. Couldn't parse revision for rc %#v, deployment controller will skip it when reconciling revisions.", err, rc)
 		} else if v >= max {

pkg/kubectl/cmd/rollout/rollout.go

@@ -43,5 +43,7 @@ func NewCmdRollout(f *cmdutil.Factory, out io.Writer) *cobra.Command {
 		},
 	}
 
+	cmd.AddCommand(NewCmdRolloutHistory(f, out))
+
 	return cmd
 }

pkg/kubectl/cmd/rollout/rollout_history.go

@@ -0,0 +1,122 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package rollout
+
+import (
+	"fmt"
+	"io"
+
+	"k8s.io/kubernetes/pkg/kubectl"
+	cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
+	"k8s.io/kubernetes/pkg/kubectl/resource"
+	"k8s.io/kubernetes/pkg/util/errors"
+
+	"github.com/spf13/cobra"
+)
+
+// HistoryOptions is the start of the data required to perform the operation.  As new fields are added, add them here instead of
+// referencing the cmd.Flags()
+type HistoryOptions struct {
+	Filenames []string
+}
+
+const (
+	history_long    = `view previous rollout revisions and configurations.`
+	history_example = `# View the rollout history of a deployment
+$ kubectl rollout history deployment/abc`
+)
+
+func NewCmdRolloutHistory(f *cmdutil.Factory, out io.Writer) *cobra.Command {
+	options := &HistoryOptions{}
+
+	cmd := &cobra.Command{
+		Use:     "history (TYPE NAME | TYPE/NAME) [flags]",
+		Short:   "view rollout history",
+		Long:    history_long,
+		Example: history_example,
+		Run: func(cmd *cobra.Command, args []string) {
+			cmdutil.CheckErr(RunHistory(f, cmd, out, args, options))
+		},
+	}
+
+	cmd.Flags().Int64("revision", 0, "See the details, including podTemplate of the revision specified")
+	usage := "Filename, directory, or URL to a file identifying the resource to get from a server."
+	kubectl.AddJsonFilenameFlag(cmd, &options.Filenames, usage)
+	return cmd
+}
+
+func RunHistory(f *cmdutil.Factory, cmd *cobra.Command, out io.Writer, args []string, options *HistoryOptions) error {
+	if len(args) == 0 && len(options.Filenames) == 0 {
+		return cmdutil.UsageError(cmd, "Required resource not specified.")
+	}
+	revisionDetail := cmdutil.GetFlagInt64(cmd, "revision")
+
+	mapper, typer := f.Object()
+
+	cmdNamespace, enforceNamespace, err := f.DefaultNamespace()
+	if err != nil {
+		return err
+	}
+
+	infos, err := resource.NewBuilder(mapper, typer, resource.ClientMapperFunc(f.ClientForMapping), f.Decoder(true)).
+		NamespaceParam(cmdNamespace).DefaultNamespace().
+		FilenameParam(enforceNamespace, options.Filenames...).
+		ResourceTypeOrNameArgs(true, args...).
+		Latest().
+		Flatten().
+		Do().
+		Infos()
+	if err != nil {
+		return err
+	}
+
+	errs := []error{}
+	for _, info := range infos {
+		mapping := info.ResourceMapping()
+		historyViewer, err := f.HistoryViewer(mapping)
+		if err != nil {
+			errs = append(errs, err)
+			continue
+		}
+		historyInfo, err := historyViewer.History(info.Namespace, info.Name)
+		if err != nil {
+			errs = append(errs, err)
+			continue
+		}
+
+		formattedOutput := ""
+		if revisionDetail > 0 {
+			// Print details of a specific revision
+			template, ok := historyInfo.RevisionToTemplate[revisionDetail]
+			if !ok {
+				return fmt.Errorf("unable to find revision %d of %s %q", revisionDetail, mapping.Resource, info.Name)
+			}
+			fmt.Fprintf(out, "%s %q revision %d\n", mapping.Resource, info.Name, revisionDetail)
+			formattedOutput, err = kubectl.DescribePodTemplate(template)
+		} else {
+			// Print all revisions
+			formattedOutput, err = kubectl.PrintRolloutHistory(historyInfo, mapping.Resource, info.Name)
+		}
+		if err != nil {
+			errs = append(errs, err)
+			continue
+		}
+		fmt.Fprintf(out, "%s\n", formattedOutput)
+	}
+
+	return errors.NewAggregate(errs)
+}

pkg/kubectl/cmd/util/factory.go

@@ -39,6 +39,7 @@ import (
 	"k8s.io/kubernetes/pkg/api/validation"
 	"k8s.io/kubernetes/pkg/apimachinery/registered"
 	"k8s.io/kubernetes/pkg/apis/extensions"
+	clientset "k8s.io/kubernetes/pkg/client/clientset_generated/release_1_1"
 	client "k8s.io/kubernetes/pkg/client/unversioned"
 	"k8s.io/kubernetes/pkg/client/unversioned/clientcmd"
 	"k8s.io/kubernetes/pkg/kubectl"
@@ -85,6 +86,8 @@ type Factory struct {
 	Scaler func(mapping *meta.RESTMapping) (kubectl.Scaler, error)
 	// Returns a Reaper for gracefully shutting down resources.
 	Reaper func(mapping *meta.RESTMapping) (kubectl.Reaper, error)
+	// Returns a HistoryViewer for viewing change history
+	HistoryViewer func(mapping *meta.RESTMapping) (kubectl.HistoryViewer, error)
 	// PodSelectorForObject returns the pod selector associated with the provided object
 	PodSelectorForObject func(object runtime.Object) (string, error)
 	// PortsForObject returns the ports associated with the provided object
@@ -313,6 +316,15 @@ func NewFactory(optionalClientConfig clientcmd.ClientConfig) *Factory {
 			}
 			return kubectl.ReaperFor(mapping.GroupVersionKind.GroupKind(), client)
 		},
+		HistoryViewer: func(mapping *meta.RESTMapping) (kubectl.HistoryViewer, error) {
+			mappingVersion := mapping.GroupVersionKind.GroupVersion()
+			client, err := clients.ClientForVersion(&mappingVersion)
+			clientset := clientset.FromUnversionedClient(client)
+			if err != nil {
+				return nil, err
+			}
+			return kubectl.HistoryViewerFor(mapping.GroupVersionKind.GroupKind(), clientset)
+		},
 		Validator: func(validate bool, cacheDir string) (validation.Schema, error) {
 			if validate {
 				client, err := clients.ClientForVersion(nil)

pkg/kubectl/describe.go

@@ -885,6 +885,20 @@ func describeReplicationController(controller *api.ReplicationController, events
 	})
 }
 
+func DescribePodTemplate(template *api.PodTemplateSpec) (string, error) {
+	return tabbedString(func(out io.Writer) error {
+		if template == nil {
+			fmt.Fprintf(out, "<no template>")
+			return nil
+		}
+		fmt.Fprintf(out, "Labels:\t%s\n", labels.FormatLabels(template.Labels))
+		fmt.Fprintf(out, "Annotations:\t%s\n", labels.FormatLabels(template.Annotations))
+		fmt.Fprintf(out, "Image(s):\t%s\n", makeImageList(&template.Spec))
+		describeVolumes(template.Spec.Volumes, out)
+		return nil
+	})
+}
+
 // JobDescriber generates information about a job and the pods it has created.
 type JobDescriber struct {
 	client *client.Client

pkg/kubectl/history.go

@@ -0,0 +1,139 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package kubectl
+
+import (
+	"fmt"
+	"io"
+	"sort"
+	"strconv"
+
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/api/unversioned"
+	"k8s.io/kubernetes/pkg/apis/extensions"
+	clientset "k8s.io/kubernetes/pkg/client/clientset_generated/release_1_1"
+	"k8s.io/kubernetes/pkg/runtime"
+	deploymentutil "k8s.io/kubernetes/pkg/util/deployment"
+	"k8s.io/kubernetes/pkg/util/errors"
+)
+
+const (
+	ChangeCauseAnnotation = "kubernetes.io/change-cause"
+)
+
+// HistoryViewer provides an interface for resources that can be rolled back.
+type HistoryViewer interface {
+	History(namespace, name string) (HistoryInfo, error)
+}
+
+func HistoryViewerFor(kind unversioned.GroupKind, c clientset.Interface) (HistoryViewer, error) {
+	switch kind {
+	case extensions.Kind("Deployment"):
+		return &DeploymentHistoryViewer{c}, nil
+	}
+	return nil, fmt.Errorf("no history viewer has been implemented for %q", kind)
+}
+
+// HistoryInfo stores the mapping from revision to podTemplate;
+// note that change-cause annotation should be copied to podTemplate
+type HistoryInfo struct {
+	RevisionToTemplate map[int64]*api.PodTemplateSpec
+}
+
+type DeploymentHistoryViewer struct {
+	c clientset.Interface
+}
+
+// History returns a revision-to-RC map as the revision history of a deployment
+func (h *DeploymentHistoryViewer) History(namespace, name string) (HistoryInfo, error) {
+	historyInfo := HistoryInfo{
+		RevisionToTemplate: make(map[int64]*api.PodTemplateSpec),
+	}
+	deployment, err := h.c.Extensions().Deployments(namespace).Get(name)
+	if err != nil {
+		return historyInfo, fmt.Errorf("failed to retrieve deployment %s: %v", name, err)
+	}
+	_, allOldRCs, err := deploymentutil.GetOldRCs(*deployment, h.c)
+	if err != nil {
+		return historyInfo, fmt.Errorf("failed to retrieve old RCs from deployment %s: %v", name, err)
+	}
+	newRC, err := deploymentutil.GetNewRC(*deployment, h.c)
+	if err != nil {
+		return historyInfo, fmt.Errorf("failed to retrieve new RC from deployment %s: %v", name, err)
+	}
+	allRCs := append(allOldRCs, newRC)
+	for _, rc := range allRCs {
+		v, err := deploymentutil.Revision(rc)
+		if err != nil {
+			return historyInfo, fmt.Errorf("failed to retrieve revision out of RC %s from deployment %s: %v", rc.Name, name, err)
+		}
+		historyInfo.RevisionToTemplate[v] = rc.Spec.Template
+		changeCause, err := getChangeCause(rc)
+		if err != nil {
+			return historyInfo, fmt.Errorf("failed to retrieve change-cause out of RC %s from deployment %s: %v", rc.Name, name, err)
+		}
+		if len(changeCause) > 0 {
+			if historyInfo.RevisionToTemplate[v].Annotations == nil {
+				historyInfo.RevisionToTemplate[v].Annotations = make(map[string]string)
+			}
+			historyInfo.RevisionToTemplate[v].Annotations[ChangeCauseAnnotation] = changeCause
+		}
+	}
+	return historyInfo, nil
+}
+
+// PrintRolloutHistory prints a formatted table of the input revision history of the deployment
+func PrintRolloutHistory(historyInfo HistoryInfo, resource, name string) (string, error) {
+	if len(historyInfo.RevisionToTemplate) == 0 {
+		return fmt.Sprintf("No rollout history found in %s %q", resource, name), nil
+	}
+	// Sort the revisionToChangeCause map by revision
+	var revisions []string
+	for k := range historyInfo.RevisionToTemplate {
+		revisions = append(revisions, strconv.FormatInt(k, 10))
+	}
+	sort.Strings(revisions)
+
+	return tabbedString(func(out io.Writer) error {
+		fmt.Fprintf(out, "%s %q:\n", resource, name)
+		fmt.Fprintf(out, "REVISION\tCHANGE-CAUSE\n")
+		errs := []error{}
+		for _, r := range revisions {
+			// Find the change-cause of revision r
+			r64, err := strconv.ParseInt(r, 10, 64)
+			if err != nil {
+				errs = append(errs, err)
+				continue
+			}
+			changeCause := historyInfo.RevisionToTemplate[r64].Annotations[ChangeCauseAnnotation]
+			if len(changeCause) == 0 {
+				changeCause = "<none>"
+			}
+			fmt.Fprintf(out, "%s\t%s\n", r, changeCause)
+		}
+		return errors.NewAggregate(errs)
+	})
+}
+
+// getChangeCause returns the change-cause annotation of the input object
+func getChangeCause(obj runtime.Object) (string, error) {
+	meta, err := api.ObjectMetaFor(obj)
+	if err != nil {
+		return "", err
+	}
+	return meta.Annotations[ChangeCauseAnnotation], nil
+}

pkg/util/deployment/deployment.go

@@ -18,6 +18,7 @@ package deployment
 
 import (
 	"fmt"
+	"strconv"
 	"time"
 
 	"k8s.io/kubernetes/pkg/api"
@@ -202,3 +203,12 @@ func getPodsForRCs(c clientset.Interface, replicationControllers []*api.Replicat
 	}
 	return allPods, nil
 }
+
+// Revision returns the revision number of the input RC
+func Revision(rc *api.ReplicationController) (int64, error) {
+	v, ok := rc.Annotations[RevisionAnnotation]
+	if !ok {
+		return 0, nil
+	}
+	return strconv.ParseInt(v, 10, 64)
+}