How to get a true remote IP behind caddy reverse proxy

[francislavoie]

@xuxueyang

		header_up Host {host}
		header_up X-Real-IP {remote}
		header_up X-Forwarded-For {remote}
        header_up X-Forwarded-Port {server_port}
        header_up X-Forwarded-Proto "http"
		trusted_proxies 172.17.0.0/20

None of this is useful in your case. You can remove all this.

Your problem is that Docker sometimes uses a userland-proxy, i.e. acts as a TCP-layer proxy in front of Caddy, which means the source IP is lost.

This isn’t a Caddy problem, but rather a Docker problem. This is a long-standing issue with Docker, for example Document how to get real remote client ip for service running in container · Issue #15086 · moby/moby · GitHub