title: Customizing Guacamole login screen when using Docker
body: <p>NOTE: I'm not a Linux expert so you might need to explain how to do things to help me resolve this issue.</p>
  
  <p>I have a fresh install of Ubuntu 16.04</p>
  
  <p>I installed Docker using this guide:
  <a href="https://www.digitalocean.com/community/tutorials/how-to-install-and-use-docker-on-ubuntu-16-04" rel="nofollow noreferrer">https://www.digitalocean.com/community/tutorials/how-to-install-and-use-docker-on-ubuntu-16-04</a></p>
  
  <p>Next I installed Guacamole as a Docker container using this guide:
  <a href="https://www.cb-net.co.uk/linux/running-guacamole-from-a-docker-container-on-ubuntu-16-04-lts-16-10/" rel="nofollow noreferrer">https://www.cb-net.co.uk/linux/running-guacamole-from-a-docker-container-on-ubuntu-16-04-lts-16-10/</a></p>
  
  <p>Guacamole works fine and all is well, however I'm trying to make some customizations to the login screen and I can't seem to figure out how.</p>
  
  <p>I understand that I need to put a jar file containing my guac-manifest.json customizations (which I already have) in the GUACAMOLE_HOME/extensions folder, which in normal circumstances would be located in /usr/share/tomcat8. However this folder (or any tomcat folders) don't exist on my system. </p>
  
  <p>As far as I can gather, the tomcat conf folder is located INSIDE of the docker container. I'm not entirely sure how to make the changes I need inside of the container, but I would like my customizations to persist if the container is updated/destroyed. Any help on how I can achieve this goal would be greatly appreciated.</p>