fix(NA): apply ipv4 first dns result order for worker threads

src/setup_node_env/dns_ipv4_first.js

@@ -0,0 +1,13 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+// enables Node 16 default DNS lookup behavior for the current thread
+require('dns').setDefaultResultOrder('ipv4first');
+
+// overrides current process node options, so it can be restored in worker threads too
+process.env.NODE_OPTIONS = `${process.env.NODE_OPTIONS || ''} --dns-result-order=ipv4first`;

src/setup_node_env/index.js

@@ -10,7 +10,7 @@
 require('./setup_env');
 
 // restore < Node 16 default DNS lookup behavior
-require('dns').setDefaultResultOrder('ipv4first');
+require('./dns_ipv4_first');
 
 require('@kbn/babel-register').install();
 require('./polyfill');