title: Docker compose with name other than dockerfile
body: <p>I have used docker to create CLI interfaces where I test my code.  These are named reasonably as:</p>
  
  <pre><code>proj_root/.../docks/foo.dockerfile
  proj_root/.../docks/bar.dockerfile
  </code></pre>
  
  <p>Because there is more than one dock involved, the top level "Dockerfile" at the project root is unreasonable.  Although I can't copy ancestor directories when building in docker, I can clone my entire repo.  </p>
  
  <p>So my project architecture works for me. </p>
  
  <hr>
  
  <p>Next, I look up <code>docker-compose</code> because I need to match my docker cards up against a postgres db and expose some ports.  </p>
  
  <p>However, docker-compose seems to be anchored to the hard-coded '"Dockerfile" in the current working directory' user concept from the perspective of the command line interface.   </p>
  
  <p>But! I see the error message implies the tool is capable of looking for an arbitrarily named dockerfile:</p>
  
  <blockquote>
    <p>ERROR: Cannot locate specified Dockerfile: Dockerfile</p>
  </blockquote>
  
  <p>The question is: how do I set <code>docker-compose</code> off looking for <code>foo.dockerfile</code> rather than <code>./Dockerfile</code>? </p>