[nix] Make own module

nixos/hosts/Tibo-NixDesk/default.nix

@@ -13,6 +13,11 @@
 
     networking.openconnect-sso.enable = true;
 
+    nix = {
+      flakes.enable = true;
+      gc.onFull.enable = true;
+    };
+
     programs = {
       home-manager.enable = true;
       sops.enable = true;
@@ -61,23 +66,11 @@
   time.timeZone = "Europe/Brussels";
 
   nix = {
-    # Allow Nix Flakes
     # Keep derivations so shells don't break (direnv)
-    # If the disk has less than 100MiB, free up to 2GiB by garbage-collecting.
     extraOptions = ''
-      experimental-features = nix-command flakes
       keep-outputs = true
       keep-derivations = true
-      min-free = ${toString (100 * 1024 * 1024)}
-      max-free = ${toString (2048 * 1024 * 1024)}
     '';
-    # Scheduled garbage-collect
-    gc = {
-      automatic = true;
-      dates = "weekly";
-      options = "--delete-older-than 30d";
-    };
-    package = pkgs.nixFlakes;
   };
 
   i18n.defaultLocale = "en_GB.UTF-8";

nixos/hosts/Tibo-NixFat/default.nix

@@ -13,6 +13,11 @@
 
     networking.openconnect-sso.enable = true;
 
+    nix = {
+      flakes.enable = true;
+      gc.onFull.enable = true;
+    };
+
     programs = {
       home-manager.enable = true;
       sops.enable = true;
@@ -94,17 +99,11 @@
   };
 
   nix = {
-    # Allow Nix Flakes
     # Keep derivations so shells don't break (direnv)
-    # If the disk has less than 100MiB, free up to 2GiB by garbage-collecting.
     extraOptions = ''
-      experimental-features = nix-command flakes
       keep-outputs = true
       keep-derivations = true
-      min-free = ${toString (100 * 1024 * 1024)}
-      max-free = ${toString (2048 * 1024 * 1024)}
     '';
-    package = pkgs.nixFlakes;
   };
 
   i18n.defaultLocale = "en_GB.UTF-8";

nixos/modules/nix/default.nix

@@ -0,0 +1,6 @@
+{
+  imports = [
+    ./flakes
+    ./gc
+  ];
+}

nixos/modules/nix/flakes/default.nix

@@ -0,0 +1,14 @@
+{ config, lib, pkgs, ... }:
+
+let
+  cfg = config.sisyphus.nix.flakes;
+in {
+  options.sisyphus.nix.flakes.enable = lib.mkEnableOption "Nix Flakes";
+
+  config.nix = lib.mkIf cfg.enable {
+    extraOptions = ''
+      experimental-features = nix-command flakes
+    '';
+    package = pkgs.nixFlakes;
+  };
+}

nixos/modules/nix/gc/default.nix

@@ -0,0 +1,25 @@
+{ config, lib, pkgs, ... }:
+
+let
+  cfg = config.sisyphus.nix.gc;
+in {
+  options.sisyphus.nix.gc = {
+    weekly.enable = lib.mkEnableOption "Scheduled Nix garbage-collection";
+    onFull.enable = lib.mkEnableOption "Nix garbage-collection when disk is almost full";
+  };
+
+  config.nix = {
+    # If the disk has less than 100MiB, free up to 2GiB by garbage-collecting.
+    extraOptions = lib.mkIf cfg.onFull.enable ''
+      min-free = ${toString (100 * 1024 * 1024)}
+      max-free = ${toString (2048 * 1024 * 1024)}
+    '';
+
+    # Scheduled garbage-collect
+    gc = lib.mkIf cfg.weekly.enable {
+      automatic = true;
+      dates = "weekly";
+      options = "--delete-older-than 30d";
+    };
+  };
+}