Augment elasticsearch-js's HttpConnector class to implement special Agent config

client.js

var elasticsearch = require('elasticsearch');
var CustomHttpConnector = require('./custom_http_connector');

module.exports = new elasticsearch.Client({
  connectionClass: CustomHttpConnector  
});

custom_http_connector.js

module.exports = CustomHttpConnector;

var EsHttpConnector = require('elasticsearch/src/lib/connectors/http');
var inherits = require('util').inherits;

function CustomHttpConnector(host, config) {
  EsHttpConnector.call(this, host, config);
}
inherits(CustomHttpConnector, EsHttpConnector);

// override the createAgent method to use whatever you would like.
CustomHttpConnector.prototype.createAgent = function (config) {
  var Agent = this.hand.Agent; // the class

  if (config.forever) {
    config.keepAlive = config.forever;
  }

  if (config.keepAlive) {
    // forever-agent doesn't seem to be compatible with 0.11, so don't use it
    // Agent = this.host.protocol === 'https' ? ForeverAgent.SSL : ForeverAgent;
    this.on('status set', this.bound.onStatusSet);
  }

  return new Agent(this.makeAgentConfig(config));
};

My ES instance is sitting behind a proxy which requires me to present my server cert. Can I use this same technique to set the following:

key: Private key to use for SSL.
passphrase: A string of passphrase for the private key or pfx.
cert: Public x509 certificate to use.
ca: An authority certificate or array of authority certificates to check the remote host against.

UPDATE: Yes, I was able to send all of my Node.js HTTPS config options using this technique(https://gist.github.com/spenceralger/8cf4977d6ac871a5f1e2/e200e07a8e55c3068b98a138c0ad8deaff12c529). Thank you for posting this!