** it's possible you'll need to modify the templates/icecast.xml file to suit your specific needs. The file as-is reflects the author's intended target and the .env.example contains example environment variables you may not (and probably will not) need/want.
$ bash init.sh
(doesn't have to be bash of course)
This will install python dependencies and build the icecast.xml config file using the template/icecast.xml file, interpolating the values provided in the .env file.
$ docker build -t your-image-name .