@PitaJ, exactly which option in the suggested nginx configuration passes the origin to the backend NodeBB?

I want to understand. Up to now, everything sounds like voodoo, such as «certain options which are dependent on the order» or «almost certainly a configuration issue». So what exactly is the problem? Which options are responsible for setting the origin? Which options depend in the order? What is why the correct order? AFAIK, order is not relevant for all options. I would like to have an educated understanding of what happens and why, not something that works by coincidence.

Ok, I suggest two thing:

• I'll help you to elaborate a Dockerfile that works fine and stable, also in swarm environments (next step will be OpenShift and upgrades).
• It would be helpful to add logging information when socket.io rejects a connection, i.e. log the detected vs the configured origin.

Agree, @PitaJ, @Tom_Rade?