reverseproxy: do not parse upstream address too early if it contains replaceble parts

[mohammed90]

Fixes #5688

[francislavoie]

I like the struct refactor! Certainly reads cleaner this way.

[francislavoie]

Do we have coverage for when the host or entire thing is a placeholder? I think we probably also want a test for when the port has a numerical prefix followed by a placeholder (as in the reported issue).

I think we can just put a lot of reverse_proxy lines in the adapt fixture with different edgecases. And maybe add some more in https://github.com/caddyserver/caddy/blob/master/modules/caddyhttp/reverseproxy/addresses_test.go

I think this looks good to me 👍

[mohammed90]

I think we probably also want a test for when the port has a numerical prefix followed by a placeholder (as in the reported issue)

I missed that and screwed it up in my second refactor 🤦🏼‍♂️

Do we have coverage for when the host or entire thing is a placeholder?

Added

[francislavoie]

LGTM but let's hear from Matt too ☺️

[mholt]

Ah wow, yeah this refactor is way better. And the new tests, love it.

Thank you for fixing this Mohammed 💯