title: Getting data in Kubernetes pod before the container starts
body: <p>I have a python program that can control a Kubernetes cluster (from outside). During that program execution, it obtains a byte array.</p>
  
  <p>I have full pod spec ready to be created.</p>
  
  <p>I need to modify the pod spec (adding an init container) so that when the main container starts, there is a file somewhere with those exact bytes.</p>
  
  <p>What's the easiest way to do that?</p>