express-http-proxy

Express proxy middleware to forward request to another host and pass response back

Install

$ npm install express-http-proxy --save

Usage

proxy(host, options);

To proxy URLS starting with '/proxy' to the host 'www.google.com':

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

var app = require('express')();

app.use('/proxy', proxy('www.google.com'));

Options

forwardPath

The forwardPath option allows you to modify the path prior to proxying the request.

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

var app = require('express')();

app.use('/proxy', proxy('www.google.com', {
  forwardPath: function(req, res) {
    return require('url').parse(req.url).path;
  }
}));

filter

The filter option can be used to limit what requests are proxied. For example, if you only want to proxy get request

app.use('/proxy', proxy('www.google.com', {
  filter: function(req, res) {
     return req.method == 'GET';
  },
  forwardPath: function(req, res) {
    return require('url').parse(req.url).path;
  }
}));

intercept

You can intercept the response before sending it back to the client.

app.use('/proxy', proxy('www.google.com', {
  intercept: function(rsp, data, req, res, callback) {
    // rsp - original response from the target
    data = JSON.parse(data.toString('utf8'));
    callback(null, JSON.stringify(data));
  }
}));

decorateRequest

You can change the request options before it is sent to the target.

app.use('/proxy', proxy('www.google.com', {
  decorateRequest: function(reqOpt, req) {
    reqOpt.headers['Content-Type'] = '';
    reqOpt.method = 'GET';
    reqOpt.bodyContent = wrap(req.bodyContent);
    return reqOpt;
  }
}));

preserveHostHdr

You can copy the host HTTP header to the proxied express server using the preserveHostHdr option.

app.use('/proxy', proxy('www.google.com', {
  preserveHostHdr: true
}));

reqBodyEncoding

Encoding used to decode request body. Default to utf-8.

Use null to avoid decoding and pass the body as is. Accept any values supported by raw-body.

app.use('/post', proxy('httpbin.org', {
  reqBodyEncoding: null
}));

timeout

By default, node does not express a timeout on connections. Use timeout option to impose a specific timeout. Timed-out requests will respond with 504 status code and a X-Timeout-Reason header.

app.use('/', proxy('httpbin.org', {
  timeout: 2000  // in milliseconds, two seconds
}));

Questions

Q: Can it support https proxy?

A: Yes, you can use the 'https-proxy-agent' package. Something like this:

var corporateProxyServer = process.env.HTTP_PROXY || process.env.http_proxy || process.env.HTTPS_PROXY || process.env.https_proxy;

if (corporateProxyServer) {
  corporateProxyAgent = new HttpsProxyAgent(corporateProxyServer);
}

Then inside the decorateRequest method, add the agent to the request:

  req.agent = corporateProxyAgent;

Release Notes

Release	Notes
0.7.4	Move jscs to devDependencies to avoid conflict with nsp.
0.7.3	Adds a timeout option. Code organization and small bug fixes.
0.7.2	Collecting many minor documentation and test improvements.
0.4.0	Signature of `intercept` callback changed from `function(data, req, res, callback)` to `function(rsp, data, req, res, callback)` where `rsp` is the original response from the target

Licence

MIT

g00fy-/express-http-proxy