plasma

modules/nixos/nix/default.nix

@@ -4,57 +4,36 @@
   namespace,
   ...
 }:
+let
+  nixSettings = lib.${namespace}.nixSettings;
+in
 {
   nix = {
-    settings = {
+    settings = nixSettings.commonSettings // {
       # extra-sandbox-paths = [ config.programs.ccache.cacheDir ];
       substituters = [
+        # NixOS-only: lantian attic cache (has some useful packages)
         "https://attic.xuyh0120.win/lantian"
-        "http://jallen-nas.local:9012/nas-cache"
-        "https://nixos-apple-silicon.cachix.org"
-        "https://nixos-raspberrypi.cachix.org"
-        "https://nix-community.cachix.org"
-        "https://cache.nixos.org/"
-      ];
+      ]
+      ++ nixSettings.commonSubstituters;
       trusted-public-keys = [
         "lantian:EeAUQ+W+6r7EtwnmYjeVwx5kOGEBpjlBfPlzGlTNvHc="
-        "nas-cache:eK0eRVAt9QNwbkLIyOo9N5Z5+zi6ukI4mSlL196C7Yg="
-        "nixos-apple-silicon.cachix.org-1:8psDu5SA5dAD7qA0zMy5UT292TxeEPzIz8VVEr2Js20="
-        "nixos-raspberrypi.cachix.org-1:4iMO9LXa8BqhU+Rpg6LQKiGa2lsNh/j2oiYLNOQ5sPI="
-        "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
-      ];
-      warn-dirty = lib.mkForce false;
-      experimental-features = lib.mkForce [
-        "nix-command"
-        "flakes"
-      ];
-      trusted-users = [
-        "@wheel"
-        "@admin"
-      ];
-
-      builders-use-substitutes = true;
-      connect-timeout = lib.mkDefault 5;
-      fallback = true;
-      log-lines = lib.mkDefault 25;
-
-      max-free = lib.mkDefault (3000 * 1024 * 1024);
-      min-free = lib.mkDefault (512 * 1024 * 1024);
+      ]
+      ++ nixSettings.commonTrustedPublicKeys;
     };
 
+    # Linux-specific: run the nix daemon at idle priority to avoid impacting
+    # interactive work during builds.
     daemonCPUSchedPolicy = lib.mkDefault "idle";
     daemonIOSchedClass = lib.mkDefault "idle";
     daemonIOSchedPriority = lib.mkDefault 7;
 
-    # Garbage collect automatically every week
-    gc = {
-      automatic = lib.mkDefault true;
-      options = lib.mkDefault "--delete-older-than 30d";
-    };
+    gc = nixSettings.commonGc;
 
     optimise.automatic = lib.mkDefault true;
   };
 
+  # Give the nix-gc systemd unit the same idle-IO treatment as the daemon.
   systemd.services.nix-gc.serviceConfig = {
     CPUSchedulingPolicy = "batch";
     IOSchedulingClass = "idle";