fix: Use ens ntp for some machines

machines/nixos/geo01/_configuration.nix

@@ -8,6 +8,7 @@ lib.extra.mkConfig {
   enabledModules = [
     # List of modules to enable
     "dgn-backups"
+    "dgn-ens-ntp"
   ];
 
   enabledServices = [

machines/nixos/geo02/_configuration.nix

@@ -8,6 +8,7 @@ lib.extra.mkConfig {
   enabledModules = [
     # List of modules to enable
     "dgn-backups"
+    "dgn-ens-ntp"
   ];
 
   enabledServices = [

machines/nixos/tower01/_configuration.nix

@@ -5,7 +5,9 @@
 { lib, ... }:
 
 lib.extra.mkConfig {
-  enabledModules = [ ];
+  enabledModules = [
+    "dgn-ens-ntp"
+  ];
 
   enabledServices = [
     "garage"

modules/nixos/default.nix

@@ -20,6 +20,7 @@
       "dgn-backups"
       "dgn-console"
       "dgn-chatops"
+      "dgn-ens-ntp"
       "dgn-firewall"
       "dgn-forgejo-runners"
       "dgn-hardware"

modules/nixos/dgn-ens-ntp.nix

@@ -0,0 +1,23 @@
+# SPDX-FileCopyrightText: 2025 Maurice Debray <maurice@dgnum.eu>
+#
+# SPDX-License-Identifier: EUPL-1.2
+
+{ config, lib, ... }:
+
+let
+  inherit (lib) mkEnableOption mkIf;
+
+  cfg = config.dgn-ens-ntp;
+in
+
+{
+  options.dgn-ens-ntp.enable = mkEnableOption "the use of ens and hackens NTP servers.";
+
+  config = mkIf cfg.enable {
+    networking.timeServers = [
+      "ntp.ens.fr"
+      "cave.hackens.org"
+    ];
+
+  };
+}