Following 12factor principle for app development, all the configuration variables for the docker images can now be setup using environment vars. The default values are set using the run.sh script in both mailman-web and mailman-core containers. Mailman-core is now run by "run.sh" which traps SIGTERM and performs mailman stop for graceful exit of mailman core.
Mailman3 Core Docker Image
To run this container, you need a valid configuration at
/opt/mailman/mailman.cfg on your host. When you spawn off this container, you
must mount /opt/mailman to the container. Mailman's var directory will also
be stored here so that it can persist across different sessions and containers.
It is not advised to run multiple mailman processes on the same host sharing the
same /opt/mailman directory as this will almost certainly be dangerous.