title: Kubernetes add ca certificate to pods' trust root
body: <p>In my 10-machines bare-metal Kubernetes cluster, one service needs to call another https-based service which is using a self-signed certificate.
  However, since this self-signed certificate is not added into pods' trusted root ca, the call failed saying can't validate x.509 certificate.</p>
  
  <p>All pods are based on ubuntu docker images. However the way to add ca cert to trust list on ubuntu (using dpkg-reconfigure ca-certificates) is not working on this pod any longer. Of course even I succeeded adding the ca cert to trust root on one pod, it's gone when another pod is kicked.</p>
  
  <p>I searched Kubernetes documents, and surprised not found any except configuring cert to talk to API service which is not what I'm looking for. It should be quite common scenario if any secure channel needed between pods. Any ideas?</p>