How to get response object in a nodejs proxy request

Question

I have a nodejs program that directs the incoming request to a couchDb server.

This is the code

/*!
 * Middleware for forwarding a request to CouchDB.
 */

/**
 * Module dependencies.
 */

var httpProxy = require('http-proxy'),
    util = require('./util');

// Set max sockets opened by proxy
var maxSocks = process.env.MAX_SOCKETS || 2048;

// Set timeout (ms) for proxy requests. Ideally this should be less than 30000ms which is Heroku timeout
var timeout = process.env.TIMEOUT || 25000;

httpProxy.setMaxSockets(maxSocks);
httpProxy.timeout = timeout;

module.exports = function(couch) {
    var proxy = new httpProxy.HttpProxy(couch),
        couchTarget = couch.target;

    return function(req, res, next) {
        console.log('Received request: ' + req.url);

        req.headers['host'] = couchTarget.host + ':' + couchTarget.port;
        req.headers['authorization'] = couch.credentials;
        req.headers['x-forwarded-ssl'] = util.isSecureForwardedRequest(req);
        var forwardedFor = req.headers['x-forwarded-for'];
        req.headers['x-real-ip'] = forwardedFor
            ? forwardedFor.split(',',1)[0]
            : req.connection.remoteAddress;
        req.url = couch.path + req.url;

        console.log('Proxying to: ' + req.url);

        var startTime = new Date().getTime();

        var res = proxy.proxyRequest(req, res);

        console.log(" Response is " + res + req);

        return res;
    }
}

The res object is always undefined. I need to handle a case if response is 404. How do we do it using the http-proxy module

Answer 1

I think proxy.proxyRequest(req, res); do not return any value, and change the param 'res' directly.
So just change your code from var res = proxy.proxyRequest(req, res); to proxy.proxyRequest(req, res);