Node 使用express-http-proxy 做api网关

拷贝代码备忘，filter过滤请求，proxyReqOptDecorator重写请求头，代码如下：

var express = require('express');
var proxy = require('express-http-proxy')

var app = express();

app.all('*', function (req, res, next) {
  res.header("Access-Control-Allow-Origin", req.headers.origin);
  res.header("Access-Control-Allow-Methods", "PUT,POST,GET,DELETE,OPTIONS");
  res.header("Access-Control-Allow-Credentials", "true");
  res.header("Content-Type", "application/json;charset=utf-8");
  if (req.method == 'OPTIONS') {
    res.header('Access-Control-Allow-Headers', req.headers['access-control-request-headers']);
    res.send(200); /*让options请求快速返回*/
  }
  else {
    next();
  }
});

// 代码转发
app.use('/ProxySSO', proxy(req => {
  return req.headers.apiurl
}, {
  filter: function (req, res) {

    // 用户名\系统标识\用户权限
    let { systemName, masterName, powers } = req.tokenDecode;
    const { originalUrl } = req;
    const url = originalUrl.replace('/ProxySSO', '').split('?')[0];

    /**
     * 接口权限检查
     * @param {String} url 接口地址
     * @param {Object} powers rbac权限列表
     * @returns {boolean} 是否有权限
     */
    const checkPowers = (url, powers) => {
        //   do something
    }
    const hasPowers = checkPowers(url, powers);
     // 权限判断
    return hasPowers;
  },
  proxyReqOptDecorator: function(proxyReqOpts, srcReq) {
    // header增加masterName  具体按照自己的需求来
    // proxyReqOpts.headers['masterName'] = srcReq.tokenDecode.masterName;
    return proxyReqOpts;
  }
}));

module.exports = app;