This has worked pretty well for me both for service control and pre-execution environment setup : https://github.com/just-containers/s6-overlay

There is also good old supervisord, but I haven't personally used it in containers yet. https://docs.docker.com/config/containers/multi-service_cont...

If you use Ubuntu then just install systemd from the repos and use that imo. Less learning for you to do if you already know how services are configured in Ubuntu.

You’ll need to point the entrypoint to /usr/bin/init.