Rewrite to flake-utils

flake.lock

@@ -1,5 +1,23 @@
 {
   "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1710146030,
+        "narHash": "sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "b1d9ab70662946ef0850d488da1c9019f3a9752a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
     "nixpkgs": {
       "locked": {
         "lastModified": 1711163522,
@@ -18,8 +36,24 @@
     },
     "root": {
       "inputs": {
+        "flake-utils": "flake-utils",
         "nixpkgs": "nixpkgs"
       }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
     }
   },
   "root": "root",

flake.nix

@@ -2,25 +2,21 @@
   description = "A simple flake to generate DKIM reports.";
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
   };
   outputs =
-    { self, nixpkgs }:
-    let
-      systems = [
-        "aarch64-darwin"
-        "aarch64-linux"
-        "x86_64-darwin"
-        "x86_64-linux"
-      ];
-      forEachSystem = nixpkgs.lib.genAttrs systems;
-    in
     {
-      packages = forEachSystem (
-        system:
-        let
-          pkgs = import nixpkgs { inherit system; };
-        in
-        {
+      self,
+      flake-utils,
+      nixpkgs,
+    }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = import nixpkgs { inherit system; };
+      in
+      {
+        packages = rec {
           dkim-report = pkgs.writeShellApplication {
             name = "reports";
             runtimeInputs = [
@@ -29,15 +25,12 @@
             ];
             text = (builtins.readFile ./reports.sh);
           };
-          default = self.packages.${system}.dkim-report;
-        }
-      );
-      apps = forEachSystem (system: {
-        dkim-report = {
-          type = "app";
-          program = "${self.packages.${system}.dkim-report}/bin/reports";
+          default = dkim-report;
         };
-        default = self.apps.${system}.dkim-report;
-      });
-    };
+        apps = rec {
+          dkim-report = flake-utils.lib.mkApp { drv = self.packages.${system}.dkim-report; };
+          default = dkim-report;
+        };
+      }
+    );
 }