I have a kubernetes cluster setup where I am trying to publish a message to google cloud pub/sub from my pod. When the POST call (created by the API behind the scenes) is being made by the pod, it fails citing the issue below:

2016/07/21 10:31:24 Publish failed, Post https://pubsub.googleapis.com/v1/projects/<project-name>/topics/MyTopic:publish?alt=json: x509: certificate signed by unknown authority

I have already put a self signed certificate in the /etc/ssl/certs of my docker Debian image. Do I need to purchase a SSL certificate signed by some certified authority or will a self signed one do the job and I am missing something out here.