# Tailscale, caddy, and nixos containers

May 16, 2023
nixos caddy tailscale self-hosting

For a little while now I’ve been running some services (jellyfin etc.) on an old laptop in my house. I’m not trying to sound like a podcast ad but as a networking novice, the simplicity tailscale brings to accessing these services remotely is very nice. Until recently though, I had been accessing my services like a heathen with http and port numbers (eg http://tailscale-ip:service-port). This works and is perfectly secure thanks to tailscale though it lacks a certain finesse. In an ideal world you’d have a reverse proxy and set up SSL certs so your browser doesn’t get stressed and you dont have to rememeber ip addresses and port numbers.

When I initially looked at how to do this it seemed like it was above my paygrade and not worth the stress; that was until I came across this. This works great and is as simple as advertised though there is one drawback: you can only reverse proxy one service per host. So for my usecase of the laptop with multiple services running on it I could only use the magic caddy tailscale auto-https thing for one of them.

### what to do?

Seeing as I was already using nixos on my latop server I turned to a slightly cumbersome nixos solution. One nixos-container for each service I wanted over https. I’d be lying If I said I completely understand all of this NAT business but this was the config I cobbled together (copied from the nixos docs).

      networking.nat = {
        enable = true;
        internalInterfaces = ["ve-+"];
        externalInterface = "ens3";
      };

      containers.jellyfin = {
        autoStart = true;
        enableTun = true;
        privateNetwork = true;
        hostAddress = "192.168.100.10";
        localAddress = "192.168.100.11";
        bindMounts = {
          "/films" = {
            hostPath = "/mnt/films";
          };
        };

        config = { pkgs, ... }: {

          services.tailscale = {
            enable = true;
            # permit caddy to get certs from tailscale
            permitCertUid = "caddy";
          };

          services.jellyfin = {
            enable = true;
            openFirewall = true;
          };

          services.caddy = {
            enable = true;
            extraConfig = ''

              jellyfin.tailnet-name.ts.net {
                reverse_proxy localhost:8096
              }

            '';
          };

          # open https port
          networking.firewall.allowedTCPPorts = [ 443 ];

          system.stateVersion = "23.05";

        };
      };
    }

This example enables the jellyfin, tailscale, and caddy services, mounts a film folder from the host, and lets the container talk to the internet.

Once you’ve logged into the container `sudo nixos-container root-login jellyfin` and authenticated with tailscale `sudo tailscale up`, you should be able to access your jellyfin in your browser at `https://jellyfin.tailnet-name.ts.net`.

As well as solving the multiple services problem, separating services onto their own hosts is nice if you want to share a particular service with someone else. I personaly feel happier just sharing one container running jellyfin rather than the whole host with multiple things on it. Anyway thanks for listening to my TED talk.