// create an elasticsearch client for your Amazon ES
let es = require('elasticsearch').Client({
  hosts: [ 'https://amazon-es-host.us-east-1.es.amazonaws.com' ],
  connectionClass: require('http-aws-es')
});

let AWS = require('aws-sdk');
AWS.config.update({
  credentials: new AWS.Credentials(accessKeyId, secretAccessKey),
  region: 'us-east-1'
});

let options = {
  hosts: [], // array of amazon es hosts (required)
  connectionClass: require('http-aws-es'), // use this connector (required)
  awsConfig: new AWS.Config({ region }), // set an aws config e.g. for multiple clients to different regions
  httpOptions: {} // set httpOptions on aws-sdk's request. default to aws-sdk's config.httpOptions
};
let es = require('elasticsearch').Client(options);