title: Docker - duplicate mount point
body: <p>I use the <a href="https://github.com/UKHomeOffice/docker-clamav" rel="noreferrer">Docker ClamAV image</a> in my <code>docker-compose.yml</code> like this:</p>
  
  <pre><code>version: '3.7'
  services:
    clamav_updater:
      image: quay.io/ukhomeofficedigital/clamav:latest
      ports:
        - "3310:3310"
      volumes:
        - type: bind
          source: /home/misc/docker/efs_clamav
          target: /var/lib/clamav
  </code></pre>
  
  <p>This service is planned to be the "updater"/"writer". This means it will download updates into <code>/var/lib/clamav</code>, and since this is a mounted volume with <code>source: /home/misc/docker/efs_clamav</code> - the reader nodes (that will not run the update command) will be able to get the updated files from that folder.</p>
  
  <p>This is all in theory. In practice, when I run this image I get the following error:</p>
  
  <blockquote>
    <p>ERROR: for clamav_writer  Cannot create container for service
    clamav_writer: Duplicate mount point: /var/lib/clamav</p>
  </blockquote>
  
  <p>I understand that this is due to the fact that the <a href="https://github.com/UKHomeOffice/docker-clamav/blob/master/Dockerfile" rel="noreferrer"><code>Dockerfile</code></a> already set the same directory as a <code>volume</code>:</p>
  
  <pre><code>VOLUME /var/lib/clamav
  </code></pre>
  
  <p>Is there anyway I can still set that volume in my <code>docker-compose.yml</code> file (so that I can set the <code>source</code> directory for other readers to read from?</p>