Is there an easy way to run this with a more-robust external db (like Postgres), without having to fork and change the Dockerfile and/or start.sh?

I was also wondering if you know what each of the ports is used for? I'd be happy to fork your repo and create a PR with more complete docker installation documentation and descriptions of what the different ports and directories are used for, if that helps, but I'm a noob to openfire, so I'm exactly sure how everything works.

Cheers.

Newly installed plugins will be removed from not being stored in a persistent directory. I attempted to add a plugins volume (./plugins:/opt/openfire/plugins) and this prevents Openfire from starting.

I'm trying to troubleshoot now. But it looks like running

docker run --rm -ti -v /data/openfire:/data luzifer/openfire

no longer pulls a working Openfire