Merge pull request #335625 from JohnRTitor/uwsm-module

nixos/uwsm: init

nixos/doc/manual/release-notes/rl-2411.section.md

@@ -33,6 +33,8 @@
 
 - [Goatcounter](https://www.goatcounter.com/), Easy web analytics. No tracking of personal data. Available as [services.goatcounter](options.html#opt-services.goatcocunter.enable).
 
+- [UWSM](https://github.com/Vladimir-csp/uwsm), a wayland session manager to wrap Wayland Compositors into useful systemd units such as `graphical-session.target`. Available as [programs.uwsm](#opt-programs.uwsm.enable).
+
 - [Open-WebUI](https://github.com/open-webui/open-webui), a user-friendly WebUI
   for LLMs. Available as [services.open-webui](#opt-services.open-webui.enable)
   service.

nixos/modules/module-list.nix

@@ -310,6 +310,7 @@
   ./programs/wayland/miracle-wm.nix
   ./programs/wayland/river.nix
   ./programs/wayland/sway.nix
+  ./programs/wayland/uwsm.nix
   ./programs/wayland/waybar.nix
   ./programs/wayland/wayfire.nix
   ./programs/weylus.nix

nixos/modules/programs/wayland/uwsm.nix

@@ -0,0 +1,129 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+let
+  cfg = config.programs.uwsm;
+
+  # Helper function to create desktop entry files for UWSM-managed compositors
+  mk_uwsm_desktop_entry =
+    opts:
+    (pkgs.writeTextFile {
+      name = "${opts.name}-uwsm";
+      text = ''
+        [Desktop Entry]
+        Name=${opts.prettyName} (UWSM)
+        Comment=${opts.comment}
+        Exec=${lib.getExe cfg.package} start -S -F ${opts.binPath}
+        Type=Application
+      '';
+      destination = "/share/wayland-sessions/${opts.name}-uwsm.desktop";
+      derivationArgs = {
+        passthru.providedSessions = [ "${opts.name}-uwsm" ];
+      };
+    });
+in
+{
+  options.programs.uwsm = {
+    enable = lib.mkEnableOption ''
+      uwsm, which wraps standalone Wayland compositors with a set
+      of Systemd units on the fly. This essentially
+      binds the wayland compositor into `graphical-session-pre.target`,
+      `graphical-session.target`, `xdg-desktop-autostart.target`.
+
+      This is useful for Wayland compositors like Hyprland, Sway, Wayfire,
+      etc. that do not start these targets and services on their own.
+
+      ::: {.note}
+      You must configure `waylandCompositors` suboptions as well
+      so that UWSM knows which compositors to manage.
+
+      Additionally, this by default uses `dbus-broker` as the dbus
+      implementation for better compatibility. If you dislike this behavior
+      you can set `services.dbus.implementation = lib.mkForce "dbus"`
+      in your configuration.
+      :::
+
+      If you are having trouble starting a service that depends on
+      `graphical-session.target`, while using a WM, enabling this option
+      might help
+    '';
+    package = lib.mkPackageOption pkgs "uwsm" { };
+
+    waylandCompositors = lib.mkOption {
+      description = ''
+        Configuration for UWSM-managed Wayland Compositors. This
+        creates a desktop entry file which will be used by Display
+        Managers like GDM, to allow starting the UWSM managed session.
+      '';
+      type = lib.types.attrsOf (
+        lib.types.submodule (
+          { ... }:
+          {
+            options = {
+              prettyName = lib.mkOption {
+                type = lib.types.str;
+                description = "The full name of the desktop entry file.";
+                example = "ExampleWaylandCompositor";
+              };
+              comment = lib.mkOption {
+                type = lib.types.str;
+                description = "The comment field of the desktop entry file.";
+                default = "An intelligent Wayland compositor managed by UWSM.";
+              };
+              binPath = lib.mkOption {
+                type = lib.types.path;
+                description = ''
+                  The wayland-compositor binary path that will be called by UWSM.
+
+                  It is recommended to use the `/run/current-system/sw/bin/` path
+                  instead of `lib.getExe pkgs.<compositor>` to avoid version mismatch
+                  of the compositor used by UWSM and the one installed in the system.
+                '';
+                example = "/run/current-system/sw/bin/ExampleCompositor";
+              };
+            };
+          }
+        )
+      );
+      example = lib.literalExpression ''
+        hyprland = {
+          prettyName = "Hyprland";
+          comment = "Hyprland compositor managed by UWSM";
+          binPath = "/run/current-system/sw/bin/Hyprland";
+        };
+        sway = {
+          prettyName = "Sway";
+          comment = "Sway compositor managed by UWSM";
+          binPath = "/run/current-system/sw/bin/sway";
+        };
+      '';
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    environment.systemPackages = [ cfg.package ];
+    systemd.packages = [ cfg.package ];
+    environment.pathsToLink = [ "/share/uwsm" ];
+
+    services.graphical-desktop.enable = true;
+
+    # UWSM recommends dbus broker for better compatibility
+    services.dbus.implementation = "broker";
+
+    services.displayManager.sessionPackages = lib.mapAttrsToList (
+      name: value:
+      mk_uwsm_desktop_entry {
+        inherit name;
+        inherit (value) prettyName comment binPath;
+      }
+    ) cfg.waylandCompositors;
+  };
+
+  meta.maintainers = with lib.maintainers; [
+    johnrtitor
+    kai-tub
+  ];
+}