HTTP proxy server (node.js)

proxy.js

// sudo npm install -g http-proxy
// sudo npm install opts

var httpProxy = require('http-proxy'),
          url = require('url'),
          net = require('net'),
         http = require('http'),
         opts = require('opts'),
           fs = require('fs');

var sys = require('util');

opts.parse([
    {
        'short': 's',
        'description': 'show log',
        'value': false,
        'required': false
    },
    {
        'short': 'r',
        'description': 'routing table file',
        'value': true,
        'required': false
    },
    {
        'short': 'p',
        'description': 'proxy port',
        'value': true,
        'required': false
    }
]);

var proxy_port = opts.get('p') || 7878;
var show_log = opts.get('s');
var routing_table = {};
if(opts.get('r')) {
    routing_table = JSON.parse(fs.readFileSync(opts.get('r'), 'utf8'));
}


process.on('uncaughtException', logError);

function truncate(str) {
    var maxLength = 256;
    return (str.length >= maxLength ? str.substring(0,maxLength) + '...' : str);
}

function logRequest(req) {
    console.log(req.method + ' ' + truncate(req.url));
    for (var i in req.headers)
        console.log(' * ' + i + ': ' + truncate(req.headers[i]));
}

function logError(e) {
    console.warn('*** ' + e);
}

var server = httpProxy.createServer(function (req, res, proxy) {
    if(show_log)
        logRequest(req);
    
    uri = url.parse(req.url);
    var host = uri.hostname;
    var port = uri.port || 80;
    
    if(routing_table[host]) {
        entry = routing_table[host];
        host = entry['host'];
        port = entry['port'];
    }
    
    proxy.proxyRequest(req, res, {
        host: host,
        port: port
    });
});

server.on('upgrade', function(req, socket, head) {
    if(show_log)
        logRequest(req);

    var parts = req.url.split(':', 2);
    var conn = net.connect(parts[1], parts[0], function() {
        socket.write("HTTP/1.1 200 OK\r\n\r\n");
        socket.pipe(conn);
        conn.pipe(socket);
    });
});

server.listen(proxy_port);