使用 http-proxy-middleware 和 Express 构建 API 网关

使用http-proxy-middleware结合Express来开发一个网关，示例代码如下：

安装依赖

npm install express http-proxy-middleware

创建服务器

const express = require('express');
const { createProxyMiddleware } = require('http-proxy-middleware');

const app = express();
const PORT = process.env.PORT || 8080;

// // 全局中间件，为所有请求添加默认请求头
app.use((req, res, next) => {
    req.headers['X-API-GATEWAY'] = 'NODE-1.0';
    next();
});

// 代理 /api/app-api 
app.use(
    '/api/app-api',
    createProxyMiddleware({
        target: 'http://app-service:4000',
        changeOrigin: true,
        pathRewrite: {
            '^/': '/api/app-api/',
        },
        on: {
            proxyReq: (proxyReq, req, res) => {
                // 添加自定义请求头
                // proxyReq.setHeader('X-APP-PACKAGE-NAME', 'werq.asdf');
                console.log('onProxyReq called for /api/app-api');
                console.log('Headers being sent to target:', proxyReq.getHeaders());
            },
        },
    })
);

// 代理 /api/products 到 http://products-service:4000
app.use(
    '/api/products',
    createProxyMiddleware({
        target: 'http://products-service:4000',
        changeOrigin: true,
        pathRewrite: {
            '^/api/products': '', // 重写路径，去掉 /api/products 前缀
        },
    })
);

// 启动服务器
app.listen(PORT, () => {
    console.log(`API Gateway running on port ${PORT}`);
});

启动服务

node filename.js

代码：https://github.com/lifengdi/node-api-gateway