add wireguard server for torus

provision/nixos/hosts/torus/configuration.nix

@@ -126,6 +126,7 @@
       samba-server.enable = true;
       jellyfin.enable = true;
       syncthing.enable = true;
+      wireguard-server.enable = true;
     };
     system = {
       terminal.enable = true;

provision/nixos/modules/services/default.nix

@@ -1,4 +1,4 @@
 { ... }:
 {
-  imports = [ ./syncthing.nix ./samba-server.nix ./samba-client.nix ./jellyfin.nix ./virt-manager.nix ./peripherals.nix ];
+  imports = [ ./wireguard-server.nix ./syncthing.nix ./samba-server.nix ./samba-client.nix ./jellyfin.nix ./virt-manager.nix ./peripherals.nix ];
 }

provision/nixos/modules/services/wireguard-server.nix

@@ -0,0 +1,54 @@
+{ config, lib, pkgs, ... }:
+
+let cfg = config.modules.services.wireguard-server;
+in {
+  options.modules.services.wireguard-server.enable = lib.mkEnableOption "wireguard-server";
+  config = lib.mkIf cfg.enable {
+    # enable NAT
+    networking.nat.enable = true;
+    networking.nat.externalInterface = "enp4s0";
+    networking.nat.internalInterfaces = [ "wg0" ];
+    networking.firewall = {
+      allowedUDPPorts = [ 51820 ];
+    };
+
+    networking.wireguard.interfaces = {
+      # "wg0" is the network interface name. You can name the interface arbitrarily.
+      wg0 = {
+        # Determines the IP address and subnet of the server's end of the tunnel interface.
+        ips = [ "10.100.0.1/24" ];
+
+        # The port that WireGuard listens to. Must be accessible by the client.
+        listenPort = 51820;
+
+        # This allows the wireguard server to route your traffic to the internet and hence be like a VPN
+        # For this to work you have to set the dnsserver IP of your router (or dnsserver of choice) in your clients
+        postSetup = ''
+          ${pkgs.iptables}/bin/iptables -t nat -A POSTROUTING -s 10.100.0.0/24 -o eth0 -j MASQUERADE
+        '';
+
+        # This undoes the above command
+        postShutdown = ''
+          ${pkgs.iptables}/bin/iptables -t nat -D POSTROUTING -s 10.100.0.0/24 -o eth0 -j MASQUERADE
+        '';
+
+        # Path to the private key file.
+        #
+        # Note: The private key can also be included inline via the privateKey option,
+        # but this makes the private key world-readable; thus, using privateKeyFile is
+        # recommended.
+        privateKeyFile = "/engi/apps/wireguard/torus-adjudicator";
+
+        peers = [
+          # List of allowed peers.
+          { # Feel free to give a meaning full name
+            # Public key of the peer (not a file path).
+            publicKey = "boy07PYDJT8TuG6Zkwg1KqhKeoakc7GH7UxAw9NuSjE";
+            # List of IPs assigned to this peer within the tunnel subnet. Used to configure routing.
+            allowedIPs = [ "10.100.0.2/32" ];
+          }
+        ];
+      };
+    };
+  };
+}