How to restart a deployment in kubernetes using go-client

Question

Is there a way to restart a kubernetes deployment using go-client .I have no idea how to achieve this ,help me!

Puffin

Deployments are not restartable! Pods are. You can delete pods, related to your deployment, and then the deployment controller recreate your pods. – Setting

Actually, a duplicate got a nice answer on #57559857 – Bibliology

I do not think it is a duplicate @DenisTrofimov. He/She asked for the client-go, not kubectl. – Coze

The 2023 answer is that deployments are restartable, just in a sugared way as they are not themselves a running process. – Tears

Answer 1

If you run kubectl rollout restart deployment/my-deploy -v=10 you see that kubectl actually sends a PATCH request to the APIServer and sets the .spec.template.metadata.annotations with something like this:

kubectl.kubernetes.io/restartedAt: '2022-11-29T16:33:08+03:30'

So, you can do this with the client-go:

clientset, err :=kubernetes.NewForConfig(config)
if err != nil {
    // Do something with err
}
deploymentsClient := clientset.AppsV1().Deployments(namespace)
data := fmt.Sprintf(`{"spec": {"template": {"metadata": {"annotations": {"kubectl.kubernetes.io/restartedAt": "%s"}}}}}`, time.Now().Format("20060102150405"))
deployment, err := deploymentsClient.Patch(ctx, deployment_name, k8stypes.StrategicMergePatchType, []byte(data), v1.PatchOptions{})
if err != nil {
    // Do something with err
}

Coze

Answer 2

You can simply set the kubectl.kubernetes.io/restartedAt annotation and update the deployment. Here is a tested snippet:

const _namespace = "default"

type client struct {
    clientset *kubernetes.Clientset
}

func (c *client) RestartDeployment(ctx context.Context, deployName string) error {
    deploy, err := c.clientset.AppsV1().Deployments(_namespace).Get(ctx, deployName, metav1.GetOptions{})
    if err != nil {
        return err
    }

    if deploy.Spec.Template.ObjectMeta.Annotations == nil {
        deploy.Spec.Template.ObjectMeta.Annotations = make(map[string]string)
    }
    deploy.Spec.Template.ObjectMeta.Annotations["kubectl.kubernetes.io/restartedAt"] = time.Now().Format(time.RFC3339)

    _, err = c.clientset.AppsV1().Deployments(_namespace).Update(ctx, deploy, metav1.UpdateOptions{})
    return err
}

Biretta

You should add explanation. – Earthquake

IMO this should be the most upvoted answer, cleaner and more concise then the current one. – Cornejo