Add nixos module

flake.nix

@@ -21,9 +21,9 @@
         inherit system;
         overlays = [(import rust-overlay)];
       };
-      rust = (pkgs.rust-bin.stable.latest.default.override {
+      rust = pkgs.rust-bin.stable.latest.default.override {
         extensions = ["rust-src"];
-      });
+      };
       # Override naersk to use our chosen rust version from rust-overlay
       naersk-lib = naersk.lib.${system}.override {
         cargo = rust;
@@ -48,5 +48,45 @@
           packages = with pkgs; [rust rust-analyzer];
         };
       formatter = pkgs.alejandra;
-    });
+      hydraJobs.build = packages.default;
+    })
+    // {
+      overlays.default = final: prev: {
+        rolebot = self.packages.${prev.system}.default;
+      };
+
+      nixosModules.default = {
+        config,
+        lib,
+        pkgs,
+        ...
+      }:
+        with lib; let
+          cfg = config.services.rolebot;
+        in {
+          options.services.rolebot = {
+            enable = mkEnableOption "Enable the rolebot service";
+            environmentFile = mkOption {
+              type = types.path;
+              description = "Path to the environment file";
+            };
+          };
+          config = mkIf cfg.enable {
+            nixpkgs.overlays = [self.overlays.default];
+            systemd.services.rolebot = {
+              description = "Discord role bot";
+              wantedBy = ["multi-user.target"];
+              after = ["network-online.target"];
+              wants = ["network-online.target"];
+              serviceConfig = {
+                User = "rolebot";
+                ExecStart = "${pkgs.rolebot}/bin/rolebot";
+                Restart = "on-failure";
+                DynamicUser = true;
+                EnvironmentFile = cfg.environmentFile;
+              };
+            };
+          };
+        };
+    };
 }