title: Calling LDAP server in GAE Flex Node throws 'getaddrinfo ENOTFOUND at GetAddrInfoReqWrap.onlookup' error
body: <p>I am using ldapjs package for ldap authentication in my nodejs application which is deployed on google cloud app engine flexible environment.</p>
  <p>The code is working fine when I run in my local machine. But it is failing on GCP.</p>
  <pre><code>var ldap = require('ldapjs');
  
  var client = ldap.createClient({
      url: 'ldap://ldap.abc.com'
  });
  
  var opts = {
      filter: '(alias='+username+')',
      scope: 'sub'
  };
  </code></pre>
  <p>This code is working when I run in my local machine. This application is deployed on GCP App Engine using flex environment. I am getting the below error when I run this code from google cloud environment.</p>
  <pre><code>Error: getaddrinfo ENOTFOUND ldap.abc.com ldap.abc.com:389 at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:67:26)
  </code></pre>