title: Unable to configure Google Cloud Pub/Sub push subscriber
body: <p>I have Google Cloud project consisting of a compute engine instance which I want to configure as a push subscriber of Cloud Pub/Sub service. I have setup an apache webserver with a self-signed certificate on the instance and have also made a DNS entry (abc.mydomain.com) which points to the instance which has a static IP address. I am already a verified owner of the domain (mydomain.com) on webmasters.</p>
  
  <p>Whenever I add the subscription from the Cloud console, it fails with the error: "The subscription could not be added" and does not show any other useful information. </p>
  
  <p>Please help.</p>