Is there a step by step diagnostic for when a Discourse site is found in a 502 Bad Gateway?

This won’t help. The back end is the issue here. It’s not getting as far as getting a response from the server (hence “bad gateway”)

it’s the backend rails logs you need to look at.

Try the actions:

  • /var/discourse/shared/standalone/log/rails# tail -n 200 production.log to see if there are obvious startup errors

  • in the container (first ./launcher enter app):

    curl 0.0.0.0:3000 to see if the rails server is responding.

Other than that remove all plugins, rebuild and then iteratively add them back.