reverse proxy

A reverse proxy is a proxy server that forwards requests to a server in an internal network and returns the results from the server to the requesting client. In layman's terms, this means that the user accesses a proxy server, which forwards the request to the real server and then returns the results from the server to the user. The advantage of this is that you can hide the real server information and only expose the proxy server information to the outside world, thus improving security.

What does a reverse proxy do?

反向代理的作用是提高了系统的安全性和可用性。在实际应用中，经常会使用反向代理来保护内部网络的安全，例如防火、负载均衡等功能都可以通过反向代理实现。另外，反向代理还可以实现缓存加速、SSL加速、内容过滤等功能，从而提高系统的性能和稳定性。

"`javascript
// Example of a Node.js implementation of a reverse proxy
const http = require('http');
const httpProxy = require('http-proxy');

// Create a reverse proxy service
const proxy = httpProxy.createProxyServer({});

// Listen for requests from proxy servers
http.createServer(function(req, res) {
// Reverse proxy to target server
proxy.web(req, res, { target: 'http://localhost:9000' });
}).listen(8000);
“`

Through the above code example, we can see that through the Node.js http module and http-proxy module can easily implement a reverse proxy server, thus improving the security and availability of the system. This is also a reflection of the reverse proxy in practical applications.