couple fixes

modules/nixos/services/cockpit/default.nix

@@ -0,0 +1,25 @@
+{
+  config,
+  lib,
+  namespace,
+  ...
+}:
+let
+  name = "cockpit";
+  cfg = config.${namespace}.services.${name};
+
+  cockpitConfig = lib.${namespace}.mkModule {
+    inherit config name;
+    description = "Cockpit web-based server management UI";
+    moduleConfig = {
+      services.cockpit = {
+        enable = true;
+        port = cfg.port;
+        openFirewall = cfg.openFirewall;
+      };
+    };
+  };
+in
+{
+  imports = [ cockpitConfig ];
+}