<p>I wanted to understand if a sidecar container can send a unix signal to the main container process).</p>
<p>The use-case is I have Nginx running as the main content serving app container and I want the sidecar container to receive Nginx config updates and reload Nginx by sending a signal. These two containers would be running in a single pod.</p>
<p>PS: I don't have an environment to try this out but wanted to check if people have used such a pattern?</p>

Bhakta Raghavan
<p>You can share process namespace by setting <code>shareProcessNamespace: true</code>.</p>
<p>The Kubernetes documentation has an example where a sidecar sends a <code>SIGHUP</code> to an nginx container in the same pod: <a href="https://kubernetes.io/docs/tasks/configure-pod-container/share-process-namespace/#configure-a-pod" rel="noreferrer">Share Process Namespace between Containers in a Pod</a>. As shown in the example, you might to add some capabilities to the container.</p>
