Add module

flake.nix

@@ -11,11 +11,26 @@
     let
       # DayZ only runs on x86_64 systems
       system = "x86_64-linux";
-      pkgs = nixpkgs.legacyPackages.${system};
-    in with pkgs; {
-      packages.${system} = {
-        default = self.packages.${system}.dzgui;
-        dzgui = (pkgs.callPackage ./. { }).overrideAttrs (_: { src = dzgui; });
+      pkgs = import nixpkgs {
+        inherit system;
+        overlays = [ self.overlays.default ];
+      };
+    in
+    with pkgs; {
+      packages.${system} = rec {
+        default = dzgui;
+        inherit (pkgs) dzgui;
+      };
+
+      overlays = {
+        default = (final: _: {
+          dzgui = (final.callPackage ./. { }).overrideAttrs (_: { src = dzgui; });
+        });
+      };
+
+      nixosModules = rec {
+        default = dzgui;
+        dzgui = import ./module.nix {inherit self;};
       };
 
       devShells.${system}.default =

module.nix

@@ -0,0 +1,25 @@
+{ self, ... }:
+{ pkgs, config, lib, ... }:
+with lib;
+let
+  cfg = config.programs.dzgui;
+in
+{
+  options.programs.dzgui = {
+    enable = mkEnableOption (mdDoc ''
+      Weather to install dzgui and setup workarounds for DayZ to work on linux
+    '');
+    package = mkOption {
+      type = with types; nullOr package;
+      default = pkgs.dzgui;
+      defaultText = literalExpression "pkgs.dzgui";
+      description = mdDoc "Dzgui package to use.";
+    };
+  };
+  config = mkIf cfg.enable {
+    # Needed by DayZ
+    boot.kernel.sysctl."vm.max_map_count" = 1048576;
+    nixpkgs.overlays = [ self.overlays.default ];
+    environment.systemPackages = [ cfg.package ];
+  };
+}