Fix missing pod name for kubectl attach and exec

The pod name is missing in suggested cmd usage when executing kubectl attach
and exec:
"Defaulting container name to master.
 Use 'kubectl describe pod/ -n default' to see all of the containers in this pod."

The PodName is empty in func Complete as the attached Pod isn't populated yet,
causing suggested cmd usage imcomplete. This patch renders PodName after it is
populated.

Author: tnqn

pkg/kubectl/cmd/attach/attach.go

@@ -68,8 +68,9 @@ type AttachOptions struct {
 	// whether to disable use of standard error when streaming output from tty
 	DisableStderr bool
 
-	CommandName       string
-	SuggestedCmdUsage string
+	CommandName             string
+	ParentCommandName       string
+	EnableSuggestedCmdUsage bool
 
 	Pod *corev1.Pod
 
@@ -183,13 +184,12 @@ func (o *AttachOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []s
 	o.Resources = args
 	o.restClientGetter = f
 
-	fullCmdName := ""
 	cmdParent := cmd.Parent()
 	if cmdParent != nil {
-		fullCmdName = cmdParent.CommandPath()
+		o.ParentCommandName = cmdParent.CommandPath()
 	}
-	if len(fullCmdName) > 0 && cmdutil.IsSiblingCommandExists(cmd, "describe") {
-		o.SuggestedCmdUsage = fmt.Sprintf("Use '%s describe pod/%s -n %s' to see all of the containers in this pod.", fullCmdName, o.PodName, o.Namespace)
+	if len(o.ParentCommandName) > 0 && cmdutil.IsSiblingCommandExists(cmd, "describe") {
+		o.EnableSuggestedCmdUsage = true
 	}
 
 	config, err := f.ToRESTConfig()
@@ -325,9 +325,9 @@ func (o *AttachOptions) containerToAttachTo(pod *corev1.Pod) (*corev1.Container,
 		return nil, fmt.Errorf("container not found (%s)", o.ContainerName)
 	}
 
-	if len(o.SuggestedCmdUsage) > 0 {
+	if o.EnableSuggestedCmdUsage {
 		fmt.Fprintf(o.ErrOut, "Defaulting container name to %s.\n", pod.Spec.Containers[0].Name)
-		fmt.Fprintf(o.ErrOut, "%s\n", o.SuggestedCmdUsage)
+		fmt.Fprintf(o.ErrOut, "Use '%s describe pod/%s -n %s' to see all of the containers in this pod.\n", o.ParentCommandName, o.PodName, o.Namespace)
 	}
 
 	klog.V(4).Infof("defaulting container name to %s", pod.Spec.Containers[0].Name)

pkg/kubectl/cmd/exec/exec.go

@@ -151,8 +151,8 @@ type ExecOptions struct {
 	ResourceName string
 	Command      []string
 
-	FullCmdName       string
-	SuggestedCmdUsage string
+	ParentCommandName       string
+	EnableSuggestedCmdUsage bool
 
 	Builder          func() *resource.Builder
 	ExecutablePodFn  polymorphichelpers.AttachablePodForObjectFunc
@@ -200,10 +200,10 @@ func (p *ExecOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, argsIn []s
 
 	cmdParent := cmd.Parent()
 	if cmdParent != nil {
-		p.FullCmdName = cmdParent.CommandPath()
+		p.ParentCommandName = cmdParent.CommandPath()
 	}
-	if len(p.FullCmdName) > 0 && cmdutil.IsSiblingCommandExists(cmd, "describe") {
-		p.SuggestedCmdUsage = fmt.Sprintf("Use '%s describe %s -n %s' to see all of the containers in this pod.", p.FullCmdName, p.ResourceName, p.Namespace)
+	if len(p.ParentCommandName) > 0 && cmdutil.IsSiblingCommandExists(cmd, "describe") {
+		p.EnableSuggestedCmdUsage = true
 	}
 
 	p.Config, err = f.ToRESTConfig()
@@ -322,11 +322,10 @@ func (p *ExecOptions) Run() error {
 	containerName := p.ContainerName
 	if len(containerName) == 0 {
 		if len(pod.Spec.Containers) > 1 {
-			usageString := fmt.Sprintf("Defaulting container name to %s.", pod.Spec.Containers[0].Name)
-			if len(p.SuggestedCmdUsage) > 0 {
-				usageString = fmt.Sprintf("%s\n%s", usageString, p.SuggestedCmdUsage)
+			fmt.Fprintf(p.ErrOut, "Defaulting container name to %s.\n", pod.Spec.Containers[0].Name)
+			if p.EnableSuggestedCmdUsage {
+				fmt.Fprintf(p.ErrOut, "Use '%s describe pod/%s -n %s' to see all of the containers in this pod.\n", p.ParentCommandName, pod.Name, p.Namespace)
 			}
-			fmt.Fprintf(p.ErrOut, "%s\n", usageString)
 		}
 		containerName = pod.Spec.Containers[0].Name
 	}