misc: refactor

checks/default.nix

@@ -0,0 +1,5 @@
+{ self, pkgs }:
+
+{
+  bird = import ./bird.nix { inherit self pkgs; };
+}

flake.nix

@@ -1,32 +1,24 @@
 {
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.05";
+    flake-utils.url = "github:numtide/flake-utils";
   };
 
-  outputs = { self, nixpkgs, ... }:
-    let
-      systems = [
-        "x86_64-linux"
-        # "aarch64-linux"
-      ];
-
-    in
-    {
+  outputs = { self, nixpkgs, flake-utils, ... }:
+    flake-utils.lib.eachDefaultSystem
+      (system:
+        let
+          pkgs = (import nixpkgs) {
+            inherit system;
+          };
+        in
+        {
+          checks = import ./checks { inherit self pkgs; };
+        }
+      ) // {
       nixosModules = rec {
         bird = ./modules;
         default = bird;
       };
-
-      checks = builtins.listToAttrs (map
-        (system: {
-          name = system;
-          value = {
-            bird = import ./checks/bird.nix {
-              inherit self;
-              pkgs = nixpkgs.legacyPackages.${system};
-            };
-          };
-        })
-        systems);
     };
 }

modules/default.nix

@@ -10,23 +10,27 @@ in
     };
 
     protocols = lib.mkOption {
-      type = with lib.types; attrsOf str;
+      type = with lib.types; attrsOf lines;
     };
   };
 
   config = lib.mkIf cfg.enable {
     services.bird2 = {
-      config = ''
-        router id ${cfg.routerId};
-
-        ${builtins.concatStringsSep "\n" (builtins.attrValues
-          (builtins.mapAttrs
+      config =
+        let
+          protocols = lib.mapAttrsToList
             (name: conf: ''
               protocol ${name} {
                 ${conf}
               }
-            '') cfg.protocols))}
-      '';
+            '')
+            cfg.protocols;
+        in
+        ''
+          router id ${cfg.routerId};
+
+          ${builtins.concatStringsSep "\n" protocols}
+        '';
     };
   };
 }