nixos/umbriel: init module

nixos/doc/manual/release-notes/rl-2611.section.md

@@ -100,6 +100,8 @@
 
 - [kvrocks_exporter](https://github.com/RocksLabs/kvrocks_exporter), a Prometheus exporter for Kvrocks metrics. Available as [services.prometheus.exporters.kvrocks](#opt-services.prometheus.exporters.kvrocks.enable).
 
+- [Umbriel](https://docs.noctalia.dev/umbriel/), a Wayland compositor built on wlroots and SceneFX. Available as [programs.umbriel](#opt-programs.umbriel.enable).
+
 ## Backward Incompatibilities {#sec-release-26.11-incompatibilities}
 
 <!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->

nixos/modules/module-list.nix

@@ -371,6 +371,7 @@
   ./programs/wayland/pinnacle.nix
   ./programs/wayland/river.nix
   ./programs/wayland/sway.nix
+  ./programs/wayland/umbriel.nix
   ./programs/wayland/uwsm.nix
   ./programs/wayland/waybar.nix
   ./programs/wayland/wayfire.nix

nixos/modules/programs/wayland/umbriel.nix

@@ -0,0 +1,48 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+let
+  cfg = config.programs.umbriel;
+in
+{
+  options.programs.umbriel = {
+    enable = lib.mkEnableOption "Umbriel, a Wayland compositor built on wlroots and SceneFX";
+    package = lib.mkPackageOption pkgs "umbriel" { };
+    portalPackage = lib.mkPackageOption pkgs "xdg-desktop-portal-umbriel" { };
+  };
+
+  config = lib.mkIf cfg.enable (
+    lib.mkMerge [
+      {
+        environment.systemPackages = [ cfg.package ];
+        services.displayManager.sessionPackages = [ cfg.package ];
+        systemd.packages = [ cfg.package ];
+
+        systemd.user.services.umbriel = {
+          restartIfChanged = false;
+          enableDefaultPath = false;
+        };
+
+        xdg.portal = {
+          enable = lib.mkDefault true;
+          extraPortals = [ cfg.portalPackage ];
+          configPackages = [ cfg.portalPackage ];
+        };
+      }
+
+      (import ./wayland-session.nix {
+        inherit lib pkgs;
+        enableXWayland = false;
+        enableWlrPortal = false;
+      })
+    ]
+  );
+
+  meta.maintainers = with lib.maintainers; [
+    samiser
+    pyrox0
+  ];
+}