title: Where to keep Dockerfile's in a project?
body: <p>I am gaining knowledge about Docker and I have the following questions</p>
  
  <ul>
  <li>Where are Dockerfile's kept in a project?
  <ul>
  <li>Are they kept together with the source?</li>
  <li>Are they kept outside of the source? Do you have an own Git repository just for the Dockerfile? </li>
  </ul></li>
  </ul>
  
  <p>If the CI server should create a new image for each build and run that on the test server, do you keep the previous image? I mean, do you tag the previous image or do you remove the previous image before creating the new one?</p>
  
  <p>I am a Java EE developer so I use Maven, Jenkins etc if that matter.</p>