Topic isn’t totally accurate. If UFW is used outside docker, as ”normally” on VPS, it doesn’t apply per se with Discourse. I can disable port 80 and it is still wide open to Discourse/docker.
Sure, it protects everything else but if there isn’t any other services listening it is unnecessary.
I don’t know how UFW or iptables works if used after enter app or can firewall use that way at all.
I’m referencing to this topic: