Can't upgrade Deployment from apiVersion extensions/v1beta1 to apps/v1, it uses extensions/v1beta1 automatically

Question

I currently have a GKE Kubernetes 1.15 cluster and I'm planning to upgrade to 1.16. Since 1.16 doesn't support certain APIs I have to change my deployments from extensions/v1beta1 to apps/v1.

Using this simple deployment.yml:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.14.2
        ports:
        - containerPort: 80

When I apply it into my 1.15 cluster: kubectl -n mynamespace deployment.yml, what is actually see is the following (kubectl -n mynamespace get deployments nginx-deployment):

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  annotations:
    deployment.kubernetes.io/revision: "1"
    kubectl.kubernetes.io/last-applied-configuration: |
...

As you can see the actual apiVersion is extensions/v1beta1 instead of apps/v1. Why isn't it applying the version I specified?

UPDATE:

This is my kubectl version:

Client Version: version.Info{Major:"1", Minor:"17", GitVersion:"v1.17.4", GitCommit:"8d8aa39598534325ad77120c120a22b3a990b5ea", GitTreeState:"clean", BuildDate:"2020-03-12T23:41:24Z", GoVersion:"go1.14", Compiler:"gc", Platform:"darwin/amd64"}
Server Version: version.Info{Major:"1", Minor:"15+", GitVersion:"v1.15.9-gke.24", GitCommit:"39e41a8d6b7221b901a95d3af358dea6994b4a40", GitTreeState:"clean", BuildDate:"2020-02-29T01:24:35Z", GoVersion:"go1.12.12b4", Compiler:"gc", Platform:"linux/amd64"}

How old is your kubectl? That's what determines which version it asks for. — coderanger
I have an up-to-date version: brew upgrade kubernetes-cli -> kubernetes-cli 1.17.4 already installed — codependent
Check with kubectl version. Sometimes people end up with an old version from google stuff. — coderanger

Mikuso Mikuso · Accepted Answer · 2020-04-04T21:20:26

The apiVersion returned from kubectl get won't necessarily match up with the actual apiVersion of your current configuration.

See here: https://github.com/kubernetes/kubernetes/issues/62283#issuecomment-380968868

Quote:

kubectl get uses server-preferred order, which will prefer the extensions API group for backward compatibility, until extensions is removed. That is to say, kubectl get deployment uses extenions/v1beta1 endpoint by default.

To get deployments under apps API group, you can use kubectl get deployment.apps, which returns you apps/v1 deployments.

Can't upgrade Deployment from apiVersion extensions/v1beta1 to apps/v1, it uses extensions/v1beta1 automatically

2 Answers