<p>TLDR: My understanding from learning all about K8s is that you need lots and lots of yaml files, however, I just deployed an app to a K8s clusters with 0 yaml files and it succeeded. Why is that? Does google cloud or K8s have defaults it uses when the app does not have any yaml file settings?</p>
<p>Longer:</p>
<ul>
<li>I have a dockerized spring app that I deployed to a google cloud cluster I created via the UI.</li>
<li>It had 0 yaml files in there, so my expectation that kubectl deploy would fail, however, it succeeded and my stateless app is up there chugging away.</li>
<li>How does that work?</li>
</ul>

stk1234
<p>Well the gcp created for you in the background. I assume you pushed your docker image or CI to cluster and from there you just did few clicks right? same stuff you can do it on openshift environment. but in the background yaml file get's generated. if you edit the pod on your UI you will see that yaml file.</p>
<p>as above @Volodymyr Bilyachat said you can create deployment via imparative way or using declarative way(yaml). I would suggest always use declarative way.</p>
<p>you can see your deployment yaml file which you created from UI by doing</p>
<pre><code>kubectl get deployment &lt;deployment_name&gt; -o yaml

kubectl get deployment &lt;deployment_name&gt; -o yaml &gt; name.yaml      #This will output your yaml file into name.yaml file
</code></pre>
