<p>I didn't notice my GKE cluster is in Rapid channel. Until today I want to add Node Pool.</p>

<p>It shows <code>Node version "1.17.5-gke.6" is unsupported.</code></p>

<p><a href="https://cloud.google.com/kubernetes-engine/docs/release-notes-rapid#may_27_2020" rel="nofollow noreferrer">https://cloud.google.com/kubernetes-engine/docs/release-notes-rapid#may_27_2020</a></p>

<p>My questions are:</p>

<ol>
<li>How to downgrade GKE master version</li>
<li>How to update a GKE cluster don't use rapid channel</li>
</ol>

<p>I can't find anything about that in gcloud cli, official documents and stackoverflow.</p>

<p>When you create a cluster you have two options to choose from</p>
<p>A. Release channel [Rapid/Regular/Stable]</p>
<p>B. Static version</p>
<p>1.How to downgrade GKE master version.</p>
<blockquote>
<p>From <a href="https://cloud.google.com/kubernetes-engine/docs/how-to/upgrading-a-cluster#about" rel="nofollow noreferrer">documentation</a>, it mentions that if you are in release channel [Rapid/Regular/Stable], downgrading is not possible.</p>
</blockquote>
<blockquote>
<p>With static version it is possible to downgrade with the following <a href="https://cloud.google.com/kubernetes-engine/docs/how-to/upgrading-a-cluster#downgrading_limitations" rel="nofollow noreferrer">limitations</a>.</p>
</blockquote>
<p>2.How to update a GKE cluster to not use rapid channel.</p>
<blockquote>
<p>This is not possible and it will give the following error</p>
</blockquote>
<pre><code>Migrating off of releaseChannel RAPID is not supported.
</code></pre>
<p>More information can be also found <a href="https://cloud.google.com/kubernetes-engine/docs/concepts/release-channels#unsubscribing_from_a_release_channel" rel="nofollow noreferrer">here</a> in regards to the migration between different release channels.</p>
