Add nixos module

flake.nix

@@ -7,6 +7,13 @@
 
   outputs = { self, nixpkgs }: nixpkgs.lib.foldAttrs (item: acc: item // acc) { } (map
     (system: with nixpkgs.legacyPackages."${system}"; {
+      devShells."${system}".default = mkShell {
+        nativeBuildInputs = [
+          nodejs_20
+          tmux
+        ];
+      };
+
       packages."${system}".default = buildNpmPackage {
         pname = "todo-list";
         version = "1.0.0";
@@ -18,11 +25,53 @@
         '';
       };
 
-      devShells."${system}".default = mkShell {
-        nativeBuildInputs = [
-          nodejs_20
-          tmux
+      nixosModules.default = { config, lib, ... }:
+        let
+          inherit (lib) mkEnableOption mkIf mkOption mkMerge types recursiveUpdate mkForce;
+          cfg = config.services.todo-list;
+        in
+        {
+          options.services.todo-list = {
+            enable = mkEnableOption "Todo list";
+
+            hostname = mkOption {
+              type = types.str;
+              example = "todo.example.com";
+              description = "The hostname to serve site on.";
+            };
+
+            nginx = mkOption {
+              type = types.submodule (
+                recursiveUpdate
+                  (import (nixpkgs + "/nixos/modules/services/web-servers/nginx/vhost-options.nix") { inherit config lib; })
+                  { }
+              );
+              default = { };
+              example = ''
+                {
+                  serverAliases = [
+                    "list.''${config.networking.domain}"
                   ];
+                  # To enable encryption and let let's encrypt take care of certificate
+                  forceSSL = true;
+                  enableACME = true;
+                }
+              '';
+              description = ''
+                With this option, you can customize the nginx virtualHost settings.
+              '';
+            };
+          };
+
+          config = mkIf cfg.enable {
+            services.nginx.virtualHosts.${cfg.hostname} = mkMerge [
+              cfg.nginx
+              {
+                root = mkForce self.packages."${system}".default;
+                locations."/".tryFiles = "$uri $uri/ /index.html";
+              }
+            ];
+          };
         };
     }) [ "x86_64-linux" "aarch64-linux" ]);
 }