title: Apache user [www-data] within a docker container can't write into a mounted volume
body: <p>Even though permissions look fine within the container:</p>
  
  <p><code>drwxrwxr-x  12 www-data www-data 4096 Dec  5 16:04 app</code></p>
  
  <p>I'm getting a permission denied error when Apache is trying to write anything into that directory.</p>
  
  <p>FYI: /app is mounted from the host machine like this:</p>
  
  <p><code>/var/www/myApp:/app</code></p>
  
  <blockquote>
    <p>Error is </p>
    
    <p>\Exception\ErrorException: file_put_contents(/app/docker.log): failed to open stream: Permission denied in /app/src/Business/ExpediteGround/LHRates/Fetch.php:13 </p>
  </blockquote>