Setting Up a Secure Tunnel Between Two Machines - eviltoast

I have two machines running docker. A (powerful) and B (tiny vps).

All my services are hosted at home on machine A. All dns records point to A. I want to point them to B and implement split horizon dns in my local network to still directly access A. Ideally A is no longer reachable from outside without going over B.

How can I forward requests on machine B to A over a tunnel like wireguard without loosing the source ip addresses?

I tried to get this working by creating two wireguard containers. I think I only need iptable rules on the WG container A but I am not sure. I am a bit confused about the iptable rules needed to get wireguard to properly forward the request through the tunnel.

What are your solutions for such a setup? Is there a better way to do this? I would also be glad for some keywords/existing solutions.

Additional info:

  • Ideally I would like to not leave docker.
  • Split horizon dns is no problem.
  • I have a static ipv6 and ipv4 on both machines.
  • I also have spare ipv6 subnets that I can use for intermediate routing.
  • I would like to avoid cloudflare.
  • 7Sea_Sailor@lemmy.dbzer0.comEnglish
    1·
    10 months ago

    Allow me to cross-post my recent post about my own infrastructure, which has pretty much exactly this established: lemmy.dbzer0.com/post/13552101.

    At the homelab (A in your case), I have tailscale running on the host and caddy in docker exposing port 8443 (though the port matters not). The external VPS (B in your case) runs docker-less caddy and tailscale (probably also works with caddy in docker when you run it in network: host mode). Caddy takes in all web requests to my domain and reverse_proxies them to the tailscale hostname of my homelab :8443. It does so with a wildcard entry (*.mydomain.com), and it forwards everything. That way it also handles the wildcard TLS certificate for the domain. The caddy instance on the homelab then checks for specific subdomains or paths, and reverse_proxies the requests again to the targeted docker container.

    The original source IP is available to your local docker containers by making use of the X-Forwarded-For header, which caddy handles beautifully. Simply add this block at the top of your Caddyfile on server A:

    {
        servers {
                trusted_proxies static 192.168.144.1/24 100.111.166.92
        }
}

    replacing the first IP with the gateway in the docker network, and the second IP with the “virtual” IP of server A inside the tailnet. Your containers, if they’re written properly, should automatically read this value and display the real source IP in their logs.

    Let me know if you have any further questions.