gistfile1.txt

var ssh = require('ssh2');
var Promise = require('bluebird');
var sshConnection = new ssh.Client();
var sshConnectionReady = false;

sshConnection.connect({
  host: config['QN_Address'],
  port: 22,
  username: 'ec2-user',
  privateKey: require('fs').readFileSync(config['QN_Key'])
});


function getConnection() {

  return new Promise((resolve, reject) => {
    if (sshConnectionReady) {
      resolve(sshConnection);
    } else {
      sshConnection
        .once('ready', function () {
          sshConnectionReady = true;
          resolve(sshConnection);
        })
        .once('end', function () {
          reject();
        })
        .once('error', function (error) {
          reject(error);
        });

    }
  });
}