I just wanted to share my experience here:
I tried setting up nodeBB and discourse with docker-compose.

While nodeBB was ready and running after 5min - by just cloning the project and starting up the stack I was not able to make discourse run in any environment after like 12 - 16 hours.

If you're self hosting - save your time. The discourse community still has no officially supported docker-compose-setup which personally i harshly criticize and which makes the impression of "self hosting" not really being a main feature of the platform.