title: Transmission permission denied in docker
body: <p>I am trying to use transmission in docker with the following docker-compose.yml file by running <code>docker-compose -f docker-compose.yml up -d</code></p>
  
  <pre><code>version: "3.6"
  services:
      transmission:
              image: lsioarmhf/transmission
              container_name: Transmission
              volumes: 
                      - ${USERDIR}/docker/transmission:/config
                      - ${USERDIR}/files/downloads/complete:/downloads/complete
                      - ${USERDIR}/files/downloads/incomplete:/downloads/incomplete
                      - "/etc/localtime:/etc/localtime:ro"
              ports: 
                      - "9091:9091"
                      - "51413:51413"
                      - "51413:51413/udp"
              restart: always
              environment:
                      - PUID=${PUID}
                      - PGID=${PGID}
                      - TZ=${TZ}
                      - TRANSMISSION_DOWNLOAD_DIR=${USERDIR}/files/downloads
  </code></pre>
  
  <p>After adding a .torrent file using the web ui at <code>localhost:9091</code> "Error: Permission Denied (/home/pi/files/downloads)" is displayed. I have tried to remedy this using <code>sudo chown pi:debian-transmission /home/pi/files/downloads -R</code> and <code>sudo chown pi:docker /home/pi/files/downloads -R</code> to no avail. I have also tried running transmission as root through docker by removing the PUID and PGID environmental variables from the file. However this poses another error saying "Error: Unable to save resume file: Permission denied"</p>
  
  <p>I am at a loss on how to fix this, does anyone know a way to get it to work?</p>