virtualization/amazon-init: enable option

nixos/modules/virtualisation/amazon-init.nix

@@ -1,6 +1,10 @@
-{ config, pkgs, ... }:
+{ config, lib, pkgs, ... }:
+
+with lib;
 
 let
+  cfg = config.virtualisation.amazon-init;
+
   script = ''
     #!${pkgs.runtimeShell} -eu
 
@@ -41,6 +45,18 @@ let
     nixos-rebuild switch
   '';
 in {
+
+  options.virtualisation.amazon-init = {
+    enable = mkOption {
+      default = true;
+      type = types.bool;
+      description = ''
+        Enable or disable the amazon-init service.
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
     systemd.services.amazon-init = {
       inherit script;
       description = "Reconfigure the system from EC2 userdata on startup";
@@ -57,4 +73,5 @@ in {
         RemainAfterExit = true;
       };
     };
+  };
 }