title: Reuse inherited image's CMD or ENTRYPOINT
body: <p>How can I include my own shell script <code>CMD</code> on container start/restart/attach, without removing the <code>CMD</code> used by an inherited image?</p>
  
  <p>I am using this, which does execute my script fine, but appears to overwrite the PHP <code>CMD</code>:</p>
  
  <pre><code>FROM php
  
  COPY start.sh /usr/local/bin
  
  CMD ["/usr/local/bin/start.sh"]
  </code></pre>
  
  <p>What should I do differently?  I am avoiding the prospect of copy/pasting the ENTRYPOINT or CMD of the parent image, and maybe that's not a good approach.</p>