nix: change values to "defaults"

Change a few of the values to be "defaults" that hosts can override if
desired.

Signed-off-by: Kenny Ballou <kballou@devnulllabs.io>

1 files changed, 4 insertions, 4 deletions

diff --git a/system/nix.nix b/system/nix.nix
index 7d8971d..2f043bc 100644
--- a/system/nix.nix
+++ b/system/nix.nix
@@ -1,12 +1,12 @@
-{ config, pkgs, ... }:
+{ config, lib, pkgs, ... }:
 {
   nix = {
     trustedUsers = [ "@wheel" ];
-    daemonIONiceLevel = 3;
-    daemonNiceLevel = 17;
+    daemonIONiceLevel = lib.mkDefault 3;
+    daemonNiceLevel = lib.mkDefault 17;
     gc = {
       automatic = true;
-      options = "--delete-older-than 14d";
+      options = lib.mkDefault "--delete-older-than 14d";
     };
     optimise = {
       automatic = true;