WireGuard server module for mothership

hosts/default.nix

@@ -185,6 +185,7 @@
         ];
         secrets = {
           "cachix" = {};
+          "mothership-wireguard-private-key" = {};
           "git-workspace-tokens".owner = "ccr";
           "magit-forge-github-token".owner = "ccr";
         };

hosts/mothership/default.nix

@@ -8,6 +8,7 @@
 }: {
   imports = fleetModules [
     "common"
+    "wireguard-server"
     "ssh"
     "ccr"
     "nix"

modules/wireguard-server/default.nix

@@ -0,0 +1,39 @@
+{
+  pkgs,
+  config,
+  ...
+}: {
+  networking.nat.enable = true;
+  networking.nat.externalInterface = "enp5s0"; # mothership network interface, shouldn't be hardcoded here
+  networking.nat.internalInterfaces = ["wg0"];
+  networking.firewall = {
+    allowedUDPPorts = [51820];
+  };
+
+  networking.wireguard.interfaces = {
+    wg0 = {
+      ips = ["10.100.0.1/24"];
+
+      listenPort = 51820;
+
+      postSetup = ''
+        ${pkgs.iptables}/bin/iptables -t nat -A POSTROUTING -s 10.100.0.0/24 -o eth0 -j MASQUERADE
+      '';
+
+      postShutdown = ''
+        ${pkgs.iptables}/bin/iptables -t nat -D POSTROUTING -s 10.100.0.0/24 -o eth0 -j MASQUERADE
+      '';
+
+      privateKeyFile = config.age.secrets."${config.networking.hostName}-wireguard-private-key".path;
+
+      peers = [
+        {
+          # thinkpad
+          publicKey = "g8wId6Rl0olRFRtAnQ046ihPRYFCtMxOJ+/Z9ARwIxI=";
+          # List of IPs assigned to this peer within the tunnel subnet. Used to configure routing.
+          allowedIPs = ["10.100.0.2/32"];
+        }
+      ];
+    };
+  };
+}

modules/wireguardClient/default.nix

@@ -1,64 +0,0 @@
-# FIXME For some reson this doesnt' work
-{
-  config,
-  lib,
-  pkgs,
-  ...
-}: {
-  networking.firewall = {
-    allowedUDPPorts = [51820]; # Clients and peers can use the same port, see listenport
-  };
-  networking.wireguard.interfaces = {
-    # "wg0" is the network interface name. You can name the interface arbitrarily.
-    wg0 = {
-      # Determines the IP address and subnet of the client's end of the tunnel interface.
-      ips = ["10.100.0.2/24"];
-      listenPort = 51820; # to match firewall allowedUDPPorts (without this wg uses random port numbers)
-
-      # 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 = "/home/ccr/wg-private"; #TODO use agenix
-
-      peers = [
-        # For a client configuration, one peer entry for the server will suffice.
-
-        {
-          # Public key of the server (not a file path).
-          publicKey = "fCwjd75CefC9A7WqO7s3xfOk2nRcoTKfnAzDT6Lc5AA=";
-
-          # Forward all the traffic via VPN.
-          allowedIPs = ["0.0.0.0/0"];
-          # Or forward only particular subnets
-          #allowedIPs = [ "10.100.0.1" "91.108.12.0/22" ];
-
-          # Set this to the server IP and port.
-          endpoint = "ccr.ydns.eu:51820"; # ToDo: route to endpoint not automatically configured https://wiki.archlinux.org/index.php/WireGuard#Loop_routing https://discourse.nixos.org/t/solved-minimal-firewall-setup-for-wireguard-client/7577
-
-          # Send keepalives every 25 seconds. Important to keep NAT tables alive.
-          persistentKeepalive = 25;
-        }
-      ];
-    };
-  };
-
-  networking.wg-quick.interfaces = {
-    wg0 = {
-      address = ["10.0.0.2/24" "fdc9:281f:04d7:9ee9::2/64"];
-      dns = ["10.0.0.1" "fdc9:281f:04d7:9ee9::1"];
-      privateKeyFile = "/home/ccr/wg-private";
-
-      peers = [
-        {
-          publicKey = "fCwjd75CefC9A7WqO7s3xfOk2nRcoTKfnAzDT6Lc5AA=";
-          # presharedKeyFile = "/root/wireguard-keys/preshared_from_peer0_key";
-          allowedIPs = ["0.0.0.0/0" "::/0"];
-          endpoint = "ccr.ydns.eu:51820";
-          persistentKeepalive = 25;
-        }
-      ];
-    };
-  };
-}

secrets/default.nix

@@ -12,6 +12,6 @@ in {
   "git-workspace-tokens.age".publicKeys = [users.ccr hosts.test hosts.mothership];
 
   # WireGuard
-
   "thinkpad-wireguard-private-key.age".publicKeys = [hosts.thinkpad];
+  "mothership-wireguard-private-key.age".publicKeys = [hosts.mothership];
 }

secrets/mothership-wireguard-private-key.age

@@ -0,0 +1,9 @@
+age-encryption.org/v1
+-> ssh-ed25519 q+UPnA 7RAJbAW7p/kUyAG7VQlVG2Ri86F13GCVw7uOGck5Yms
+KJQCDEH6PQF8H4uUFp5cuvtLb4Yldvl35NXqbYyxUYQ
+-> 2x%m?X4r-grease [L7Jb/. xgMVomN[
+in0zvAfoC0s/CLqNviUa2NfGJR1R4BjbkKCzNYsjJd7JUG+R1hda7Vku7SQ5yA1D
+SzSeDISN7PK6dVBDlt2vzgqZnJpNswnSu23qdlfiQ2f9N/LA7gKD9uB5YF5wac2h
+rgY
+--- 3m0T9+VQCfTh6uuvoilEvtu57x6UbXsRf73k40O2v9k
+¢‘]jòßí¦£SUt<NJ_¹}ïÉœe0ÉŽºž/n7AÜòÙa™©þ¼'úÂhDz¨c-C4B?ÿ¾LŽû:
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