title: How to change Docker config of an already running container?
body: <p>I have installed <a href="https://github.com/getsentry/onpremise" rel="nofollow noreferrer">Sentry onpremise</a> and after some time tinkering I got it to work and changed the <code>system.url-prefix</code> option to the correct URL using the command line. However there are 2 problems still:</p>
  
  <ul>
  <li>This option is not persistant</li>
  <li>You cannot do the same for the <code>mail.from</code> option, which can only be set before running.</li>
  </ul>
  
  <p>There are 3 config files at play, but not all of them register and that makes it confusing.</p>
  
  <ol>
  <li>sentry.conf.py</li>
  </ol>
  
  <p>Containing </p>
  
  <pre><code>SENTRY_OPTIONS['system.url-prefix'] = 'https://sentry.mydomain.com'
  SENTRY_OPTIONS['mail.from'] = 'sentry@mydomain.com'
  </code></pre>
  
  <ol start="2">
  <li>config.yml</li>
  </ol>
  
  <p>Containing</p>
  
  <pre><code>mail.from: 'sentry@mydomain.com'
  system.url-prefix: 'https://sentry.mydomain.com'
  </code></pre>
  
  <ol start="3">
  <li>docker-compose.yml</li>
  </ol>
  
  <p><a href="https://i.stack.imgur.com/Da4Te.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Da4Te.png" alt="enter image description here"></a></p>
  
  <p>Restarting the containers does not load the new config. </p>
  
  <p><a href="https://github.com/getsentry/onpremise/issues/13" rel="nofollow noreferrer">Related issue</a>. However I don't know what to do after changing the config like in the comment (<code>SENTRY_OPTIONS['mail.from']</code>)</p>