node.js forward proxy example

fproxy.js

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

var url = require('url');
var net = require('net');
var http = require('http');

process.on('uncaughtException', function (err) {
    console.error('! uncaughtException: ' + err.stack);
});

function truncate(str)
{
    var maxLength = 100;
    return (str.length >= maxLength ? str.substring(0,maxLength) + '...' : str);
}

function logRequest(req)
{
    console.log(req.method + ' ' + truncate(req.url));
}

function logRewrite(uri)
{
    console.log(" + Rewrite: " + uri);
}

var regularProxy = new httpProxy.RoutingProxy();

function rewriteUrl(uri)
{
    if (uri === "http://stackoverflow.com/questions/18569733/running-a-forward-proxy-server-in-nodejitsu-using-node-js")
    {
        uri = "http://ngyuki.hatenablog.com/entry/2013/12/11/003959";
        logRewrite(uri);
    }

    return uri;
}

function rewriteHttps(host)
{
    if (host === "github.com")
    {
        host = "bitbucket.org";
        logRewrite(host);
    }

    return host;
}

var server = http.createServer();

server.on('request', function(req, res) {
    logRequest(req);

    req.url = rewriteUrl(req.url);

    var uri = url.parse(req.url);

    regularProxy.proxyRequest(req, res, {
        host: uri.hostname,
        port: uri.port || 80
    });
});

server.on('connect', function(req, socket, head) {
    logRequest(req);

    var parts = req.url.split(':', 2);

    var host = rewriteHttps(parts[0]);
    var port = parts[1];

    var conn = net.connect(port, host, function() {
        socket.write("HTTP/1.1 200 OK\r\n\r\n");
        socket.pipe(conn);
        conn.pipe(socket);
    });
});

server.listen(8888);

package.json

{
  "dependencies": {
    "http-proxy": "~0.10.3"
  }
}