test building optimized packages

modules/nix/settings.nix

@@ -1,6 +1,8 @@
 { lib, inputs, config, pkgsVersion, ... }:
 with lib;
-let cfg = config.custom.nix.settings;
+let
+  cfg = config.custom.nix.settings;
+  cache = "https://cache.nixos.org";
 in {
   options.custom.nix.settings = {
     enable = mkEnableOption "Enables various nix settings";
@@ -18,6 +20,11 @@ in {
     nix = {
       optimise.automatic = cfg.optimise;
       settings.experimental-features = [ "nix-command" "flakes" ];
+      settings.substituters =
+        lib.mkIf (config.networking.hostName == "kop-pc")
+        [ "http://192.168.0.20:5000" ];
+      settings.trusted-public-keys =
+        [ "amd-server:r5S7vv/3sZ0knhMvpUzRHXFlBHgov2tLhtoKqLXYf28=" ];
       registry.nixpkgs.flake = pkgsVersion;
       gc = {
         automatic = true;

modules/services/nix-cache.nix

@@ -0,0 +1,18 @@
+{ config, ... }: {
+
+  age.secrets.binary-cache = {
+    file = ../../secrets/binary-cache.age;
+  };
+  nix.sshServe = {
+    enable = true;
+    keys = [
+      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIFeP6qtVqE/gu72ZUZE8cdRi3INiUW9NqDR7SjXIzTw2 kopatz"
+    ];
+  };
+  services.nix-serve = {
+    enable = true;
+    openFirewall = true;
+    port = 5000;
+    secretKeyFile = config.age.secrets.binary-cache.path;
+  };
+}