<p>We have some workloads running on GKE. They got deployed in early 2020 and have not really been touched since then.</p>
<p>Google has sent us instructions for upgrading, however we don't want to, because the workload is only going to be used for some further months.</p>
<p>My question is, what happens to clusters with older versions of Kubernetes in case they can not be auto-upgraded, as in our case? We assume that they will simply continue to run, however we need confirmation. Auto-upgrade is not possible because we have the docker runtime and that is not compatible with newer containerd runtimes, which are used now in the current versions of GKE.</p>
<p>Anyone has any experience with this situation?</p>

fgu
<p>GKE will most definitely upgrade both the control plane and worker nodes.  As of the latest <a href="https://cloud.google.com/kubernetes-engine/docs/release-notes#April_11_2022" rel="nofollow noreferrer">release</a>, 1.18 clusters will be upgraded to 1.19.16-gke.8300 which will go end of life in June, 2022.  1.19 still has the Docker runtime so there should be no issues there.</p>
