var options = {
  AccessKeyId: 'xxxx-xxxx-xxxx-xxxx',
  AccessKeySecret: 'xxxx-xxxx-xxxx-xxxx',
  // 选填，不同接口类型注意版本日期
  Version: '2014-05-26',
  // 选填
  SignatureMethod: 'HMAC-SHA1',
  Format: 'json',
  SignatureVersion: '1.0',
  // 每次请求都会自动重新生成
  SignatureNonce: Math.random(),
  Timestamp: new Date().toISOString()
};

var WALIYUN = require('waliyun');
// 加载全部方法
var ecs = WALIYUN.ECS(options);
// 或加载某些方法
var ecs = WALIYUN.ECS(options, ['DescribeInstances', 'DescribeInstanceStatus']);
// 或加载某个方法
var ecs = WALIYUN.ECS(options, 'DescribeInstances');
ecs
  .describeInstances({
    RegionId: 'cn-hangzhou'
  })
  .then(function (instances) {
    // xxxx
  });

import { ECS } from 'waliyun';
const ecs = ECS(options);
// Within Async Func
async () => {
  const instances = await ecs.describeInstances({
    RegionId: 'cn-hangzhou'
  });
  // xxxx
};