express反向代理中间件http-proxy-middleware

http-proxy-middleware用于把请求代理转发到其他服务器的中间件。

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

var app = express();

app.use('/api', proxy({
    target: 'http://localhost:4000/', 
    changeOrigin: true
}));
app.listen(3000);

在3000端口启动了http服务，利用了app.use('/api', proxy({target: 'http://localhost:4000/', changeOrigin: true}))，请求localhost:3000/api，被转发到4000端口，相当于请求http://localhost:4000/api。 

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

var app = express();

app.use('/api', proxy({
    target: 'https://www.baidu.com', 
    changeOrigin: true,
    pathRewrite: {
        '^/api' : '',
        '^/api/old-path'