nixos-module/defaults: let journald log to volatile storage

nix/nixos-module/defaults.nix

@@ -11,6 +11,12 @@
   # Includes wireguard
   boot.kernelPackages = pkgs.linuxPackages_latest;
 
+  # no persistent logs
+  services.journald.extraConfig = ''
+    RuntimeMaxUse=32M
+    Storage=volatile
+  '';
+
   nix = {
     package = pkgs.nixFlakes;
     extraOptions = "experimental-features = nix-command flakes";