Add tailscale configuration for WSL2

Related to https://github.com/tailscale/tailscale/issues/562

machines/gallantis/configuration.nix

@@ -28,6 +28,8 @@ in {
 
     # Enable integration with Docker Desktop
     docker.enable = true;
+
+    tailscale.enable = true;
   };
 
   # Enable nix flakes

machines/gallantis/nixos-wsl/flake.nix

@@ -23,6 +23,7 @@
           ./modules/build-tarball.nix
           ./modules/wsl-distro.nix
           ./modules/docker-desktop.nix
+          ./modules/tailscale.nix
           ./modules/installer.nix
         ];
       };

machines/gallantis/nixos-wsl/modules/tailscale.nix

@@ -0,0 +1,34 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+with builtins;
+with lib; {
+  options.wsl.tailscale = with types; {
+    enable = mkEnableOption "Tailscale for WSL";
+  };
+
+  config = let
+    cfg = config.wsl.tailscale;
+  in
+    mkIf (config.wsl.enable && cfg.enable) {
+      environment.systemPackages = with pkgs; [
+        tailscale
+      ];
+
+      systemd.services.tailscaled = {
+        description = "Tailscale WSL";
+        script = ''
+          ${pkgs.tailscale}/bin/tailscaled
+        '';
+        wantedBy = ["multi-user.target"];
+        serviceConfig = {
+          Restart = "on-failure";
+          RestartSec = "30s";
+        };
+      };
+
+    };
+}