title: Docker: Edit "my.cnf" file in stopped container
body: <p>After making an edit to "my.cnf", I now get an error from Kitematic on the Mac when I attempt to start the container:</p>
  
  <pre><code>mysqld: [ERROR] Found option without preceding group in config file /etc/mysql/my.cnf at line 19! mysqld: 
          [ERROR] Fatal error in defaults handling. Program aborted!
  </code></pre>
  
  <p>I've tried accessing the container via:</p>
  
  <pre><code>docker exec -it [container] bash
  </code></pre>
  
  <p>... but I get the error:</p>
  
  <pre><code>Error response from daemon: Container [container] is not running
  </code></pre>
  
  <p>I was able to access <em>something</em> via the image, but the file didn't appear to be the same, so I'm not sure what was happening (I'm not too conversant with Docker).</p>
  
  <p>At this stage, either making the appropriate edit and fixing the container, or somehow cloning the MySQL data to another container would be ideal.</p>