title: How to transfer a value from one build container to another in drone.io CI pipeline
body: <p>I know I can write it to the mounted host file system which will be shared amongst the multiple build containers. But how can I make use of that file in a drone plugin container like docker-plugin?</p>
  
  <p>Or, is there any other way to pass arbitrary data between build steps? Maybe through environment variables?</p>
  
  <p>This is drone 0.5</p>