title: Docker error on an entrypoint script: "no such file or directory"
body: <p>I'm using Docker image <code>ubuntu:trusty</code> and have an <code>entrypoint.sh</code> file contains</p>
  
  <pre><code>#!/bin/bash
  . /appenv/bin/activate
  exec $@
  </code></pre>
  
  <p>In <code>Dockerfile</code> contains for entrypoint scripts</p>
  
  <pre><code>ADD scripts/entrypoint.sh /usr/local/bin/entrypoint.sh
  RUN chmod +x /usr/local/bin/entrypoint.sh
  ENTRYPOINT ["entrypoint.sh"]
  </code></pre>
  
  <p>got an error <code>exec user process caused "no such file or directory"</code></p>