use the regex match of subdomain

[FrancYescO]

i'm trying witouth success to proxy a range of subdomain to another host/path.. something like this

reproxy --static.enabled --static.rule="(.*).example.com,(.*),https://$1.foo.com/$2"

that should result in
http://AAAA.example.com/UUUU proxied to https://AAAA.foo.com/UUUU

Is this possible somehow?

[umputun]

moved to discussion

[umputun]

You expect it to pass the matched group from the server and propagate to the destination, and this is not how it works because
the regex match is for source->destination only; it doesn't work for the case you have (server->destination). See

reproxy/app/discovery/discovery.go

Line 181 in fa23778

dest := m.SrcMatch.ReplaceAllString(src, m.Dst)

The regex in the server name is to match multiple servers to the same rule. However, it has nothing to do with source-to-destination matching at all.

Making a change to support it should be relatively easy, but I don't know if this is a good idea because it looks very confusing. It treats the server and source as a single regex for the destination but simultaneously as two distinct matching groups for the host and source. In addition to this confusion, we will need a way to enforce the current behavior (regex server match and substitution from src to dst) and ensure it doesn't break back compatibility.

[FrancYescO]

with a static provider: reproxy --static.enabled --static.rule="example.com/api/(.*),https://api.example.com/$1"

This was taken from the docs and is missing the host parameter, idk is it is a typo... maybe is the best solution also for backward compatibility: if host is missing (2 parameter instead of 3 splitted by the comma) use the 1st parameter to match also the host (and get the ability to use both group match in the destination)

[umputun]

yeah, I missed the first parameter in docs, fixed

if host is missing (2 parameter instead of 3 splitted by the comma) use the 1st parameter to match also the host (and get the ability to use both group match in the destination)

interesting idea. in this case, we will need to infer the host from the source parameter and also make sure this host part is included in the match.

If you want to make a PR I'll accept it in case it doesn't add much complexity (I don't think it will) and won't break back compatibility

[FrancYescO]

unfortunately i don't have a ready to go dev enviroment that allow me fast testing.. i'll go for a PR if i figure out how to setup it..