Modularize everything

modules/services/flatpak.nix

@@ -0,0 +1,19 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+with lib.my;
+
+let cfg = config.modules.services.flatpak;
+in {
+  options.modules.services.flatpak = { enable = mkBoolOpt false; };
+
+  config = mkIf cfg.enable {
+    services.flatpak.enable = true;
+
+    xdg.portal = {
+      enable = true;
+      extraPortals = [ pkgs.xdg-desktop-portal-gtk ];
+    };
+
+  };
+}