<p>I am using kOps to perform a manual cluster upgrade (from 1.17 to 1.18) as explained at <a href="https://kops.sigs.k8s.io/operations/updates_and_upgrades/#upgrading-kubernetes" rel="nofollow noreferrer">https://kops.sigs.k8s.io/operations/updates_and_upgrades/#upgrading-kubernetes</a></p>
<p>I've noticed that kOps does not update the ami-image defined at <code>spec.image</code> at ig nodes, that means after cluster upgrade nodes are going to use the same base OS despite the kubernetes upgrade. But if you install 1.18 from scratch kOps uses the latest image available for that version.</p>
<p>should i update the version and configure it the same as the one kOps would use in case of an installation from scratch?</p>
<p>In 1.18 ami has moved from Debian to Ubuntu, should i take any precautions due to the change of operating system?</p>

jmhostalet
<p>There was a bug up until kOps 1.18.2 where Ubuntu images were considered &quot;custom&quot; and therefore not upgraded by <code>kops upgrade</code>. See <a href="https://github.com/kubernetes/kops/issues/10021" rel="nofollow noreferrer">this bug</a></p>
<p>As of 1.18.2, you should see upgrades for Ubuntu as well.</p>
<p>There is no particular need to take any precaution when switching from Debian to Ubuntu unless you are using kOps hooks that would be Debian. kOps will take care of this change for you.</p>
