First version.

flake.nix

@@ -0,0 +1,33 @@
+{
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }: {
+    serviceConfig =
+      let
+        system = flake-utils.lib.system.x86_64-linux;
+        lib = nixpkgs.lib;
+        nixosConfig = nixpkgs.lib.nixosSystem {
+          inherit system;
+          specialArgs = { };
+          modules = [ ./modules ];
+        };
+        services = lib.flip lib.genAttrs
+          (serviceName:
+            nixosConfig.config.systemd.units."${serviceName}.service".unit)
+          # TODO: generate this list from the config instead of hard coding
+          [
+            "service-1"
+            "service-2"
+          ];
+      in
+      nixpkgs.legacyPackages.${system}.writeTextFile {
+        name = "services";
+        destination = "/services.json";
+        text = lib.generators.toJSON { } services;
+      };
+  };
+}