nix-common: Add option for gc interval

machines/heimdall/configuration.nix

@@ -1,8 +1,5 @@
-{ self, ... }@inputs:
+{ self, ... }:
 { modulesPath, lib, ... }:
-# let
-#   pkgs = self.inputs.nixpkgs.legacyPackages.x86_64-linux;
-# in
 {
   imports = [
     "${modulesPath}/profiles/qemu-guest.nix"
@@ -26,6 +23,7 @@
     keycloak.enable = true;
     nix-common = {
       enable = true;
+      gc-interval = "03:15";
     };
   };
 

modules/nix-common/default.nix

@@ -17,6 +17,11 @@ in
       type = with types; listOf str;
       default = [ ];
     };
+    gc-interval = mkOption {
+      description = "How often to run nix-collect-garbage";
+      type = types.str;
+      default = "weekly";
+    };
   };
 
   imports = [
@@ -82,7 +87,7 @@ in
 
       gc = {
         automatic = true;
-        dates = "weekly";
+        dates = cfg.gc-interval;
         options = "--delete-older-than 30d";
       };
     };