@gekkonen I got mine running again. As a workaround, to force the Internet to work from Docker, you can configure the docker0 network to use “promiscuous” mode:
[root@forum /var/discourse]# ifconfig docker0 promisc
You should then be able to use the launcher to rebuild the app, and the Discourse forum should work fine. The caveat is that you probably will have to issue the command again after each reboot.
Let me know if it works for you.
I still don’t know the root cause of the problem.