Dynamically proxy based on subdomain

[hpo]

1. The problem I’m having:

I’ve been running caddy for a couple years now, but I have a very simple setup and still consider myself a beginner so please bear with me.

• My main use for caddy is turning all my insecure http connections to https connections. It’s not so much a security concern as it is an annoyance to get invalid cert popups and the fact that my browser won’t fill in passwords on insecure http.
• My network endpoints all use dns (server1. example. com, server2. example. com etc).
• My caddy server is p. example. com
• I currently have everything mapped by hand so server1. p. example. com points to server1. example. com

I want to know if its possible to dynamically grab the subdomain “server1” from server1. p. example. com, and forward to server1. example. com

2. Error messages and/or full log output:

N/A

3. Caddy version:

Version 2.8.4

4. How I installed and ran Caddy:

Installed using official guide

a. System environment:

Ubuntu 24.04.1

[fds]

Yes, of course. Probably could be even simpler than this, but only went ahead and slightly modified an existing config of mine:

https://*.p.example.com {
	@hostprefix vars_regexp hostprefix {host} ^([^.]+)\.
	handle @hostprefix {
		map {re.hostprefix.1} {rp_hostport} {
			~^.*$ "${0}.example.com:80"
		}
		reverse_proxy {rp_hostport}
	}
}

[Mohammed90 (Mohammed Al Sahaf)]

You can just use reverse_proxy {labels.3}.example.com

Common Caddyfile Patterns - Caddy Documentation

[hpo]

That worked!! Thanks!

Added the following as a catch-all at the end of my caddyfile

handle {
     reverse_proxy {labels.3}.example.com:80
}

It wouldn’t work without the port 80 on the end.
I now realize some of my endpoints are https and some are http. I don’t suppose there is a way for it to automatically check each to see which it should forward to.