title: How to increase max_connection in the official PostgreSQL Docker image
body: <h2>Problem</h2>
  
  <p>I have too many connection open using the default docker <code>postgresql</code> configuration </p>
  
  <ul>
  <li><a href="https://hub.docker.com/_/postgres/" rel="noreferrer">https://hub.docker.com/_/postgres/</a></li>
  </ul>
  
  <h2>Goal</h2>
  
  <p>I want to extend <code>max_connection</code> without using a volume for mounting the configuration (I need this to be available by default for my CI environment).</p>
  
  <p>I have tried to use <code>sed</code> to edit the configuration but this has no effect. </p>
  
  <p>What is the recommended way of overriding default configuration of postgresql docker official image?</p>