K8s upgrade from 1.20 to 1.21 without upgrading etcd

Upgrade kubernetes controlplane without upgrading etcd pod. I was thinking these steps:

  1. kubectl -n kube-system get po etcd-controlplane -o yaml > etcd-po-backup.yaml
  2. kubeadm upgrade apply 1.21.0
  3. Restore the old etcd pod from the yaml file from Step 1.

Do you see any issues with these steps? Any other suggestions or thoughts?


You can use the cli flag --etcd-upgrade false when performing the upgrade. See the reference docs here: kubeadm upgrade | Kubernetes