kubectl: simplify Rollbacker interface

pkg/kubectl/cmd/rollout/rollout_undo.go

@@ -129,7 +129,7 @@ func (o *UndoOptions) CompleteUndo(f *cmdutil.Factory, cmd *cobra.Command, out i
 func (o *UndoOptions) RunUndo() error {
 	allErrs := []error{}
 	for ix, info := range o.Infos {
-		result, err := o.Rollbackers[ix].Rollback(info.Namespace, info.Name, nil, o.ToRevision, info.Object)
+		result, err := o.Rollbackers[ix].Rollback(info.Object, nil, o.ToRevision)
 		if err != nil {
 			allErrs = append(allErrs, cmdutil.AddSourceToErr("undoing", info.Source, err))
 			continue

pkg/kubectl/rollback.go

@@ -33,7 +33,7 @@ import (
 
 // Rollbacker provides an interface for resources that can be rolled back.
 type Rollbacker interface {
-	Rollback(namespace, name string, updatedAnnotations map[string]string, toRevision int64, obj runtime.Object) (string, error)
+	Rollback(obj runtime.Object, updatedAnnotations map[string]string, toRevision int64) (string, error)
 }
 
 func RollbackerFor(kind unversioned.GroupKind, c client.Interface) (Rollbacker, error) {
@@ -48,13 +48,16 @@ type DeploymentRollbacker struct {
 	c client.Interface
 }
 
-func (r *DeploymentRollbacker) Rollback(namespace, name string, updatedAnnotations map[string]string, toRevision int64, obj runtime.Object) (string, error) {
-	d := obj.(*extensions.Deployment)
+func (r *DeploymentRollbacker) Rollback(obj runtime.Object, updatedAnnotations map[string]string, toRevision int64) (string, error) {
+	d, ok := obj.(*extensions.Deployment)
+	if !ok {
+		return "", fmt.Errorf("passed object is not a Deployment: %#v", obj)
+	}
 	if d.Spec.Paused {
-		return "", fmt.Errorf("you cannot rollback a paused deployment; resume it first with 'kubectl rollout resume' and try again")
+		return "", fmt.Errorf("you cannot rollback a paused deployment; resume it first with 'kubectl rollout resume deployment/%s' and try again", d.Name)
 	}
 	deploymentRollback := &extensions.DeploymentRollback{
-		Name:               name,
+		Name:               d.Name,
 		UpdatedAnnotations: updatedAnnotations,
 		RollbackTo: extensions.RollbackConfig{
 			Revision: toRevision,
@@ -63,16 +66,16 @@ func (r *DeploymentRollbacker) Rollback(namespace, name string, updatedAnnotatio
 	result := ""
 
 	// Get current events
-	events, err := r.c.Events(namespace).List(api.ListOptions{})
+	events, err := r.c.Events(d.Namespace).List(api.ListOptions{})
 	if err != nil {
 		return result, err
 	}
 	// Do the rollback
-	if err := r.c.Extensions().Deployments(namespace).Rollback(deploymentRollback); err != nil {
+	if err := r.c.Extensions().Deployments(d.Namespace).Rollback(deploymentRollback); err != nil {
 		return result, err
 	}
 	// Watch for the changes of events
-	watch, err := r.c.Events(namespace).Watch(api.ListOptions{Watch: true, ResourceVersion: events.ResourceVersion})
+	watch, err := r.c.Events(d.Namespace).Watch(api.ListOptions{Watch: true, ResourceVersion: events.ResourceVersion})
 	if err != nil {
 		return result, err
 	}