Update kubernetes deployment object with Go package-CodePudding

I have the following code snippet:

// patchDeploymentReplicas updates the number of replicas of a given deployment
func patchDeploymentReplicas(ctx context.Context, cs *kubernetes.Clientset, ns, d string, repl int) error {
    err := retry.RetryOnConflict(retry.DefaultRetry, func() error {
        result, err := cs.AppsV1().Deployments(ns).Get(context.TODO(), d, metav1.GetOptions{})
        if err != nil {
            return err
        }
        fmt.Println(*result.Spec.Replicas) // debug
        result.Spec.Replicas = flip(int32(repl))
        _, err = cs.AppsV1().Deployments(ns).Update(context.TODO(), result, metav1.UpdateOptions{})
        fmt.Println(*result.Spec.Replicas) // debug
        return err
    })
    if err != nil {
        return err
    }
    return nil
}

func flip(i int32) *int32 {
    return &i
}

which is mostly from the Official client-go documentation.

However, when I run this code in (Minikube) cluster, the following happens:

{"level":"debug","routine":"suspender","namespace":"plop","deployment":"misc-depl","time":"2021-10-05T15:26:19Z","message":"scaling misc-depl from 1 to 0 replicas"}
1
1
{"level":"debug","routine":"suspender","namespace":"plop","deployment":"misc-depl","time":"2021-10-05T15:26:19Z","message":"scaling misc-depl from 1 to 0 replicas"}
1
1

(the JSON log line comes from another function).

We can see that the deployment object is not updated, which is confirmed when I use kubectl:

❯ k get deployments.apps -n plop -w
NAME                     READY   UP-TO-DATE   AVAILABLE   AGE
kube-ns-suspender-depl   0/0     0            0           3h2m
misc-depl                1/1     1            1           9m29s
^C

However, when I edit the deployment manually (kubectl edit -n plop deployments.apps misc-depl), it scales to 0 without any problem.

I have tried both the answers proposed here and none of them worked for me.

I guess the object I'm editing in my code is in reality a copy of the one I would like to edit, but I'm not sure how to debug and fix this.

EDIT

It seems that the issue comes from the fact that I want to scale to 0. I tried the reversed operation (scale from 0 to 1 replica) and it worked like a charm.

SECOND AND LAST EDIT

It was indeed a PEBCAK :(

Solved!

CodePudding user response：

It was a logical issue elsewhere in the code.