title: Health Check command for docker(1.12) container (Not in Dockerfile!)
body: <p>Docker Version <code>1.12</code>,
  I got a <code>Dockerfile</code> from <a href="https://github.com/docker/docker/issues/23962" rel="noreferrer">Here</a></p>
  
  <pre><code>FROM nginx:latest
  
  RUN touch /marker
  
  ADD ./check_running.sh /check_running.sh
  RUN chmod +x /check_running.sh
  
  HEALTHCHECK --interval=5s --timeout=3s CMD ./check_running.sh
  </code></pre>
  
  <p>I'm able to roll the updates and health checks with <code>check_running.sh</code> shell script. Here, the <code>check_running.sh</code> script is copied to <code>image</code>, so the launched container has it.</p>
  
  <p>Now, my question is there any way to Health Check from out side of the container and script also located outside. </p>
  
  <p>I'm excepting a health check command to get the container performance(Depends on what we wrote in script), IF the container is not performing good it should roll-back to previous version ( <em>Kind of a process that monitors the containers, if it is not good, it should roll-back to previous</em>)</p>
  
  <p>Thanks</p>