NodeJS實現websocket代理機制

• 使用的模塊
  • ws
  • http
  • http-proxy
• 主要通過htt-proxy實現中轉
  
  
• 啟動websocket服務

var WebSocketServer = require('ws').Server;
var wss             = new WebSocketServer({port: 6443});

console.log(6443);
wss.on('connection', function connection(ws) {
    ws.on('message', function incoming(message) {
        console.log('received: %s', message);
        ws.send(message);
    });
});

wss.on('error', function (error) {
    console.log('error:', error);
});

• 啟動http-proxy代理伺服器

　　註意：客戶端發送的數據websocket已加密無法直接獲得，該演示通過ws模塊中的PerMessageDeflate實現解密。黃色區域代碼請自行調整

const http              = require('http');
const httpProxy         = require('http-proxy');
const ws                = require('ws');
const Receiver          = ws.Receiver;
const Extensions        = ws.Extensions;
const PerMessageDeflate = ws.PerMessageDeflate;
const proxy             = new httpProxy.createProxyServer({target: 'ws://localhost:6443', ws: true});
const proxyServer       = http.createServer(function(req, res) {
    proxy.web(req, res);
});

proxyServer.on('upgrade', function(req, socket, head) {
    let extensions        = {};
    let perMessageDeflate = new PerMessageDeflate({}, true);
    let serverExtensions  = Extensions.parse(req.headers['sec-websocket-extensions']);
    perMessageDeflate.accept(serverExtensions[PerMessageDeflate.extensionName]);
    extensions[PerMessageDeflate.extensionName] = perMessageDeflate;
    let _receiver                               = new Receiver(extensions, 0);

    socket.on('data', function(data) {
        _receiver.add(data);
    });

    _receiver.ontext = function ontext(data, flags) {
        console.log('客戶端請數據:', data);
    };

    _receiver.onclose = function onclose(code, data, flags) {
        console.log('onclose:', data);
    };

    _receiver.onerror = function onerror(reason, errorCode) {
        console.log('onerror:', reason);
    };

    proxy.ws(req, socket, head);
});

proxyServer.on('error', function(error) {
    console.log('error:', error);
});

proxy.on('open', function(proxySocket) {
    let extensions        = {};
    let perMessageDeflate = new PerMessageDeflate({}, true);
    let serverExtensions  = Extensions.parse(proxySocket._httpMessage._headers['sec-websocket-extensions']);
    perMessageDeflate.accept(serverExtensions[PerMessageDeflate.extensionName]);
    extensions[PerMessageDeflate.extensionName] = perMessageDeflate;
    let _receiver                               = new Receiver(extensions, 0);

    proxySocket.on('data', function(data) {
        _receiver.add(data);
    });

    _receiver.ontext = function ontext(data, flags) {
        console.log('代理伺服器返回數據:', data);
    };
});

proxyServer.listen(8080);

• 代理伺服器日誌：

　　　　客戶端請數據: 222222

　　　　代理伺服器返回數據: 222222

　　　　客戶端請數據: client----1

　　　　代理伺服器返回數據: client----1

　　　　客戶端請數據: client----2

　　　　代理伺服器返回數據: client----2