Added tailscale config

modules/services/tailscale/default.nix

@@ -0,0 +1,50 @@
+{
+  options,
+  config,
+  pkgs,
+  lib,
+  ...
+}:
+with lib; let
+  cfg = config.aa.services.tailscale;
+in {
+  options.aa.services.tailscale = with types; {
+    enable = mkEnableOption "tailscale";
+    configureClientRouting = mkOption {
+      type = bool;
+      default = false;
+      description = mdDoc ''
+        Configures tailscale as a client.
+
+        See `options.services.tailscale.useRoutingFeatures` for more information.
+      '';
+    };
+    configureServerRouting = mkOption {
+      type = bool;
+      default = false;
+      description = mdDoc ''
+        Configures tailscale as a server.
+
+        See `options.services.tailscale.useRoutingFeatures` for more information.
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
+    environment.systemPackages = [pkgs.tailscale];
+    networking.firewall.allowedUDPPorts = [config.services.tailscale.port];
+    services.tailscale = {
+      enable = true;
+      useRoutingFeatures = mkIf (cfg.configureClientRouting || cfg.configureServerRouting) (
+        if (cfg.configureClientRouting && cfg.configureServerRouting)
+        then "both"
+        else
+          (
+            if cfg.configureClientRouting
+            then "client"
+            else "server"
+          )
+      );
+    };
+  };
+}