title: file_put_contents permission inside Docker
body: <p>I'm having issues on write files inside a docker container. Always receiving a permission denied message.</p>
  
  <p>I already tried using the following inside Dockerfile but any of them worked.</p>
  
  <pre><code>RUN chown -R www-data:www-data /var/www/html/folder
  </code></pre>
  
  <p>or</p>
  
  <pre><code>RUN chmod 775 -R /var/www/html/folder
  </code></pre>
  
  <p>Any clues?</p>
  
  <p>Thanks.</p>