Add support for reverse proxy to atlassian/bamboo-server docker image

Problem

Adding proxy support to the atlassian/bamboo-server docker image would save the admin's time when setting up Bamboo instances using docker.

At the moment this is not available:

Known issues
No support for configuring a reverse proxy for Bamboo.

Reference: https://hub.docker.com/r/atlassian/bamboo-server

Current alternative

Mount the custom server.xml file

If you need to use a customized server.xml file, you can easily do it by mounting it from the host filesystem into the container. Assuming that your custom server.xml file is present in the current working directory just add the following option to the docker run command:

-v $(pwd)/server.xml:/opt/atlassian/bamboo/conf/server.xml

(on)Note that you must use an absolute path, otherwise a directory will be created.