add basic nixosModule for tasklist

flake.nix

@@ -3,9 +3,58 @@
 
   outputs = { self, nixpkgs }: {
 
-    packages.x86_64-linux.hello = nixpkgs.legacyPackages.x86_64-linux.hello;
+    packages.x86_64-linux.tasklist = nixpkgs.legacyPackages.x86_64-linux.buildGoModule rec {
+      pname = "tasklist";
+      version = "1.0";
+      vendorHash = "sha256-olHQNClxU4sykBlhlbvTL6wCUYkMxnaQdLnRwvuJffw=";
+      src = ./.;
+    };
 
-    packages.x86_64-linux.default = self.packages.x86_64-linux.hello;
+    nixosModules.malobeo-tasklist = { config, ... }: 
+    let
+      cfg = config.services.malobeo-tasklist;
+      tasklist-pkg = self.packages.x86_64-linux.tasklist;
+    in
+    {
+      options = {
+        services.malobeo-tasklist = {
+          enable = nixpkgs.lib.mkOption {
+            default = false;
+            type = nixpkgs.types.bool;
+            description = nixpkgs.lib.mdDoc ''
+              Enables tasklist
+              '';
+          };
+        };
+      };
 
+      config = nixpkgs.lib.mkIf cfg.enable {
+        environment.systemPackages = [ tasklist-pkg];
+
+        users.users = {
+          malobeo-tasklist = {
+            description = "malobeo tasklist user";
+            group = "malobeo-tasklist";
+            isNormalUser = true;
+          };
+        };
+
+        systemd.services.malobeo-tasklist = {
+          description = "malobeo tasklist daemon";
+          serviceConfig = {
+            Type = "simple";
+            ExecStart = "${tasklist-pkg}/bin/tasklist -d /var/lib/malobeo-tasklist/tasklist.db";
+            Restart = "on-failure";
+          };
+
+          wantedBy = [ "default.target" ];
+
+          environment = {
+            USER = "malobeo-tasklist";
+            HOME = /var/lib/malobeo-tasklist;
+          };
+        };
+      };
+    };
   };
 }