How do I set up multiple ports on localhost to a single backend?

[francislavoie]

You need to use the rewrite directive to change the request path. You can’t pass the request path directly to reverse_proxy, it only takes upstream addresses.

But keep in mind:

The "subfolder problem", OR, "why can't I reverse proxy my app into a subfolder?"

Have you ever tried to reverse proxy an app into its own little subfolder of your domain name? Makes things neat, doesn’t it? Using example.com/foo/ for one app, example.com/bar/ for another. If you’re coming here from one of the selfhosted communities, you might be thinking along the lines of example.com/sonarr/, example.com/radarr/ etc. Chances are, you’ve tried some configuration along these lines: example.com { redir /sonarr /sonarr/ handle_path /sonarr/* { reverse_proxy localhost…

You’re probably better off using subdomains for each, like foo.localhost and bar.localhost.