<p>For example, I have an internal docker registry for my kube cluster, hosted on <code>internal-docker-registry.io:5000</code>.</p>
<p>When the pod from the kube cluster pulling image <code>busybox</code>, I don't want to pull from docker hub <code>docker.io</code>. But instead I want it to pull from <code>internal-docker-registry.io:5000</code>.</p>
<p><em>Note that I cannot change the image name to <code>internal-docker-registry.io:5000/busybox</code> since I don't own the spec and there are too man these kind of third party image in my cluster.</em></p>

<p>I have posted community wiki answer to summarize the topic:</p>
<p>As <a href="https://stackoverflow.com/users/10008173/david-maze" title="76,777 reputation">David Maze</a> well mentioned in the comment:</p>
<blockquote>
<p><strong>there is no &quot;image registry search list&quot;</strong>; an image name without a registry <em>always</em> uses <code>docker.io</code>, to avoid surprises where <em>e.g.</em>  <code>FROM ubuntu</code> means something different depending on local configuration.</p>
</blockquote>
<p>So if you can't change the image name to internal-docker-registry.io:5000/busybox then unfortunately you don't have the option to get the image from your private registry (according to David's comment).</p>
<p>See also similar questions:</p>
<p><a href="https://stackoverflow.com/questions/33054369/how-to-change-the-default-docker-registry-from-docker-io-to-my-private-registry">How to change the default docker registry from docker.io to my private registry?</a></p>
<p><a href="https://stackoverflow.com/questions/66026479/how-to-change-default-k8s-cluster-registry">How to change default K8s cluster registry?</a></p>
