feat(flake): systemd service

flake.nix

@@ -80,5 +80,60 @@
         });
 
       defaultPackage = eachSystem (system: self.packages.${system}.default);
+
+      nixosModules.default =
+        {
+          config,
+          lib,
+          pkgs,
+          ...
+        }:
+        let
+          cfg = config.services.noctalia-shell;
+        in
+        {
+          options.services.noctalia-shell = {
+            enable = lib.mkEnableOption "Noctalia shell systemd service";
+
+            package = lib.mkOption {
+              type = lib.types.package;
+              default = self.packages.${pkgs.system}.default;
+              description = "The noctalia-shell package to use";
+            };
+
+            target = lib.mkOption {
+              type = lib.types.str;
+              default = "graphical-session.target";
+              example = "hyprland-session.target";
+              description = "The systemd target for the noctalia-shell service.";
+            };
+          };
+
+          config = lib.mkIf cfg.enable {
+            systemd.user.services.noctalia-shell = {
+              description = "Noctalia Shell - Wayland desktop shell";
+              documentation = [ "https://github.com/noctalia-dev/noctalia-shell" ];
+              after = [ cfg.target ];
+              partOf = [ cfg.target ];
+              wantedBy = [ cfg.target ];
+
+              unitConfig = {
+                StartLimitIntervalSec = 60;
+                StartLimitBurst = 3;
+              };
+
+              serviceConfig = {
+                ExecStart = "${cfg.package}/bin/noctalia-shell";
+                Restart = "on-failure";
+                RestartSec = 3;
+                TimeoutStartSec = 10;
+                TimeoutStopSec = 5;
+                Environment = [ "PATH=${config.system.path}/bin" ];
+              };
+            };
+
+            environment.systemPackages = [ cfg.package ];
+          };
+        };
     };
 }