Socket hangup while posting request to Node-http-p

Question

I'm working in Node.js Project and I want node to act as a proxy for solr

For proxy: I used Node-http-proxy. the problem is that proxy work excellent in case of get requests but in case of post requests it results in socket hang up exception

Here is a sample of my node code

var express = require('express');
var router = express.Router();

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

var proxyOptions = {
  host: "127.0.0.1",
  port: 8983
};
var proxy = httpProxy.createProxyServer(proxyOptions);

// It works excellent in GET request
router.get('/solr/*', function(req, res) {
  proxy.web(req, res, {
    target: 'http://' + proxyOptions.host + ':' + proxyOptions.port
  });
})

// the socket hang up in post request
router.post('/solr/*', function(req, res) {
  console.log('Post Request');
  proxy.web(req, res, {
    target: 'http://' + proxyOptions.host + ':' + proxyOptions.port
  });
})

And this is the error after some time in node console

Error: socket hang up
    at createHangUpError (http.js:1476:15)
    at Socket.socketOnEnd [as onend] (http.js:1572:23)
    at Socket.g (events.js:180:16)
    at Socket.emit (events.js:117:20)
    at _stream_readable.js:943:16
    at process._tickCallback (node.js:419:13)

Any suggestions about the cause of the problem

Answer 1

Use a callback to listen for the error:

proxy.web(req, res, { target: 'http://mytarget.com:8080' }, function(e) { ... });

from https://github.com/nodejitsu/node-http-proxy

Answer 2

I found the solution to this problem with the help of this issue https://github.com/nodejitsu/node-http-proxy/issues/180#issuecomment-12244852

the solution is to use middleware for proxy before using the bodyparser

code sample

 // use middleware first 
app.post('/solr/*',function(req, res) {
  console.log('POST REQUEST')
  //res.end();
   proxy.web(req, res, {
     target: 'http://' + proxyOptions.host + ':' + proxyOptions.port
   });
})
app.use(logger('dev'));
// use bodyparser after that
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));

Answer 3

I think the issue comes from the order of middleware. Using bodyParser before httpProxy will break the requests with JSON body, so httpProxy should be used before bodyParser.

You may want to check this for more info about bodyParser.