os/hosts/frikandel/wireguard.nix

{
  flake,
  config,
  pkgs,
  lib,
  ...
}: with lib; {
  age.secrets.wg-private-key-server.file = "${flake.self}/secrets/wg-private-frikandel-server.age";

  boot.kernel.sysctl = {
    "net.ipv4.ip_forward" = 1;
    "net.ipv6.conf.wg0.forwarding" = 1;
    "net.ipv6.conf.wg0.accept_ra" = 1;
    "net.ipv6.conf.wg0.accept_ra_pinfo" = 1;
  };

  networking.nat = {
    enable = true;
    enableIPv6 = true;
    externalInterface = "enp1s0";
    internalInterfaces = [ "wg0" ];
  };

  networking.firewall.allowedUDPPorts = [ 51899 ];
  networking.firewall.extraForwardRules = [
    "iifname { != wg0 } reject"
    "iifname wg0 accept"
  ];

  systemd.services.wireguard-wg0 = {
    after = [
      "network.target"
      "network-online.target"
      "nss-lookup.target"
    ];

    serviceConfig = {
      Type = mkForce "simple";
      Restart = "on-failure";
      RestartSec = "30";
    };

    environment = {
      WG_ENDPOINT_RESOLUTION_RETRIES = "infinity";
    };
  };

  # Enable WireGuard
  networking.wireguard.interfaces = {
    wg0 = {
      listenPort = 51899;
      mtu = 1300;
      ips = [
        "10.13.12.7/32"
        "fd00:b12f:acab:1312:acab:7::/96"
      ];
      privateKeyFile = "/run/agenix/wg-private-key-server";
      peers = [
        { # pie
          publicKey = "hPTXEqQ2GYEywdPNdZBacwB9KKcoFZ/heClxnqmizyw=";
          allowedIPs = [
            "10.13.12.2/32"
            "fd00:b12f:acab:1312:acab:2::/96"
          ];
          endpoint = "pie-wg.b12f.io:51899";
          persistentKeepalive = 25;
        }
        { # droppie
          publicKey = "qsnBMoj9Z16D8PJ5ummRtIfT5AiMpoF3SoOCo4sbyiw=";
          allowedIPs = [
            "10.13.12.3/32"
            "fd00:b12f:acab:1312:acab:3::/96"
          ];

          persistentKeepalive = 25;
        }
        { # chocolatebar
          publicKey = "nk8EtGE/QsnSEm1lhLS3/w83nOBD2OGYhODIf92G91A=";
          allowedIPs = [
            "10.13.12.5/32"
            "fd00:b12f:acab:1312:acab:5::/96"
          ];

          persistentKeepalive = 25;
        }
        { # biolimo
          publicKey = "4ymN7wwBuhF+h+5fFN0TqXmVyOe1AsWiTqRL0jJ3CDc=";
          allowedIPs = [
            "10.13.12.6/32"
            "fd00:b12f:acab:1312:acab:6::/96"
          ];

          persistentKeepalive = 25;
        }
        { # stroopwafel
          publicKey = "5iNRg13utOJ30pX2Z8SjwPNUFwfH2zonlbeYW2mKFkU=";
          allowedIPs = [
            "10.13.12.8/32"
            "fd00:b12f:acab:1312:acab:8::/96"
          ];

          persistentKeepalive = 25;
        }
      ];
    };
  };
}