<p>I need to block my k8s pods from writing to root folders, with an exemption to /tmp dir. There are 2 reasons I need to write to this dir:</p>

<ol>
<li>Flask needs to write to somewhere. It's trying to write to /tmp and /etc/... and /opt/... , but all of them are blocked because it's under root folder</li>
<li>I'm going to need to write to a file for liveness probe, but if the entire file system is blocked, then I can't do it</li>
</ol>

<p>I'm running kubernetes 1.13.6-gke.13 in GKE</p>

<p>The relevant part from the yaml file:</p>

<pre><code>securityContext:
  runAsUser: 1000
  readOnlyRootFilesystem: true
  runAsNonRoot: true
</code></pre>

<p>I expect the pod to be able to write to a predefined folder, maybe a mounted one.</p>

<p>Create a volume mount for /tmp directory.</p>

<pre><code>volumeMounts:
- mountPath: /tmp
  name: tmp
</code></pre>

<p>And in Volumes - </p>

<pre><code>volumes:
- emptyDir: {}
  name: tmp
</code></pre>
