github/kubernetes
1
0
Fork 0
mirror of https://github.com/k3s-io/kubernetes.git synced 2025-07-29 06:27:05 +00:00
Code Issues Projects Releases Wiki Activity

Add backwards compatibility for kubectl debug

Browse Source 
The ephemeral containers API changed in 1.22. As a result, kubectl
debug (currently) cannot create ephemeral containers in clusters prior
to 1.22.

This change causes kubectl to retry the request using the old API when
it receives a specific error message from the server.
This commit is contained in:
Lee Verberne 2021-06-28 18:19:50 +02:00
parent a0f9c8c277
commit 06124c1d1c
1 changed files with 43 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
staging/src/k8s.io/kubectl/pkg/cmd/debug/debug.go
View File

@ -124,7 +124,7 @@ type DebugOptions struct {
attachChanged bool
shareProcessedChanged bool
podClient corev1client.PodsGetter
podClient corev1client.CoreV1Interface
genericclioptions.IOStreams
}
@ -413,12 +413,54 @@ func (o *DebugOptions) debugByEphemeralContainer(ctx context.Context, pod *corev
if serr, ok := err.(*errors.StatusError); ok && serr.Status().Reason == metav1.StatusReasonNotFound && serr.ErrStatus.Details.Name == "" {
return nil, "", fmt.Errorf("ephemeral containers are disabled for this cluster (error from server: %q).", err)
}
// The Kind used for the /ephemeralcontainers subresource changed in 1.22. When presented with an unexpected
// Kind the api server will respond with a not-registered error. When this happens we can optimistically try
// using the old API.
if runtime.IsNotRegisteredError(err) {
klog.V(1).Infof("Falling back to legacy API because server returned error: %v", err)
return o.debugByEphemeralContainerLegacy(ctx, pod, debugContainer)
}
return nil, "", err
}
return result, debugContainer.Name, nil
}
// debugByEphemeralContainerLegacy adds debugContainer as an ephemeral container using the pre-1.22 /ephemeralcontainers API
// This may be removed when we no longer wish to support releases prior to 1.22.
func (o *DebugOptions) debugByEphemeralContainerLegacy(ctx context.Context, pod *corev1.Pod, debugContainer *corev1.EphemeralContainer) (*corev1.Pod, string, error) {
// We no longer have the v1.EphemeralContainers Kind since it was removed in 1.22, but
// we can present a JSON 6902 patch that the api server will apply.
patch, err := json.Marshal([]map[string]interface{}{{
"op": "add",
"path": "/ephemeralContainers/-",
"value": debugContainer,
}})
if err != nil {
return nil, "", fmt.Errorf("error creating JSON 6902 patch for old /ephemeralcontainers API: %s", err)
}
result := o.podClient.RESTClient().Patch(types.JSONPatchType).
Namespace(pod.Namespace).
Resource("pods").
Name(pod.Name).
SubResource("ephemeralcontainers").
Body(patch).
Do(ctx)
if err := result.Error(); err != nil {
return nil, "", err
}
newPod, err := o.podClient.Pods(pod.Namespace).Get(ctx, pod.Name, metav1.GetOptions{})
if err != nil {
return nil, "", err
}
return newPod, debugContainer.Name, nil
}
// debugByCopy runs a copy of the target Pod with a debug container added or an original container modified
func (o *DebugOptions) debugByCopy(ctx context.Context, pod *corev1.Pod) (*corev1.Pod, string, error) {
copied, dc, err := o.generatePodCopyWithDebugContainer(pod)