node-http-proxy README

The project's README from github.com/http-party/node-http-proxy. As one markdown file: README.md.

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node-http-proxy is an HTTP programmable proxying library that supports websockets. It is suitable for implementing components such as reverse proxies and load balancers.

Table of Contents

Installation

npm install http-proxy --save

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Upgrading from 0.8.x ?

Click here

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Core Concept

A new proxy is created by calling createProxyServer and passing an options object as argument (valid properties are available here)

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

var proxy = httpProxy.createProxyServer(options); // See (†)

†Unless listen(..) is invoked on the object, this does not create a webserver. See below.

An object will be returned with four methods:

It is then possible to proxy requests by calling these functions

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

Errors can be listened on either using the Event Emitter API

proxy.on('error', function(e) {
  ...
});

or using the callback API

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

When a request is proxied it follows two different pipelines (available here) which apply transformations to both the req and res object. The first pipeline (incoming) is responsible for the creation and manipulation of the stream that connects your client to the target. The second pipeline (outgoing) is responsible for the creation and manipulation of the stream that, from your target, returns data to the client.

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Use Cases

Setup a basic stand-alone proxy server

var http = require('http'),
    httpProxy = require('http-proxy');
//
// Create your proxy server and set the target in the options.
//
httpProxy.createProxyServer({target:'http://localhost:9000'}).listen(8000); // See (†)

//
// Create your target server
//
http.createServer(function (req, res) {
  res.writeHead(200, { 'Content-Type': 'text/plain' });
  res.write('request successfully proxied!' + '\n' + JSON.stringify(req.headers, true, 2));
  res.end();
}).listen(9000);

†Invoking listen(..) triggers the creation of a web server. Otherwise, just the proxy instance is created.

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Setup a stand-alone proxy server with custom server logic

This example shows how you can proxy a request using your own HTTP server and also you can put your own logic to handle the request.

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

//
// Create a proxy server with custom application logic
//
var proxy = httpProxy.createProxyServer({});

//
// Create your custom server and just call `proxy.web()` to proxy
// a web request to the target passed in the options
// also you can use `proxy.ws()` to proxy a websockets request
//
var server = http.createServer(function(req, res) {
  // You can define here your custom logic to handle the request
  // and then proxy the request.
  proxy.web(req, res, { target: 'http://127.0.0.1:5050' });
});

console.log("listening on port 5050")
server.listen(5050);

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Setup a stand-alone proxy server with proxy request header re-writing

This example shows how you can proxy a request using your own HTTP server that modifies the outgoing proxy request by adding a special header.

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

//
// Create a proxy server with custom application logic
//
var proxy = httpProxy.createProxyServer({});

// To modify the proxy connection before data is sent, you can listen
// for the 'proxyReq' event. When the event is fired, you will receive
// the following arguments:
// (http.ClientRequest proxyReq, http.IncomingMessage req,
//  http.ServerResponse res, Object options). This mechanism is useful when
// you need to modify the proxy request before the proxy connection
// is made to the target.
//
proxy.on('proxyReq', function(proxyReq, req, res, options) {
  proxyReq.setHeader('X-Special-Proxy-Header', 'foobar');
});

var server = http.createServer(function(req, res) {
  // You can define here your custom logic to handle the request
  // and then proxy the request.
  proxy.web(req, res, {
    target: 'http://127.0.0.1:5050'
  });
});

console.log("listening on port 5050")
server.listen(5050);

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Modify a response from a proxied server

Sometimes when you have received a HTML/XML document from the server of origin you would like to modify it before forwarding it on.

Harmon allows you to do this in a streaming style so as to keep the pressure on the proxy to a minimum.

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Setup a stand-alone proxy server with latency

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

//
// Create a proxy server with latency
//
var proxy = httpProxy.createProxyServer();

//
// Create your server that makes an operation that waits a while
// and then proxies the request
//
http.createServer(function (req, res) {
  // This simulates an operation that takes 500ms to execute
  setTimeout(function () {
    proxy.web(req, res, {
      target: 'http://localhost:9008'
    });
  }, 500);
}).listen(8008);

//
// Create your target server
//
http.createServer(function (req, res) {
  res.writeHead(200, { 'Content-Type': 'text/plain' });
  res.write('request successfully proxied to: ' + req.url + '\n' + JSON.stringify(req.headers, true, 2));
  res.end();
}).listen(9008);

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Using HTTPS

You can activate the validation of a secure SSL certificate to the target connection (avoid self-signed certs), just set secure: true in the options.

HTTPS -> HTTP
//
// Create the HTTPS proxy server in front of a HTTP server
//
httpProxy.createServer({
  target: {
    host: 'localhost',
    port: 9009
  },
  ssl: {
    key: fs.readFileSync('valid-ssl-key.pem', 'utf8'),
    cert: fs.readFileSync('valid-ssl-cert.pem', 'utf8')
  }
}).listen(8009);
HTTPS -> HTTPS
//
// Create the proxy server listening on port 443
//
httpProxy.createServer({
  ssl: {
    key: fs.readFileSync('valid-ssl-key.pem', 'utf8'),
    cert: fs.readFileSync('valid-ssl-cert.pem', 'utf8')
  },
  target: 'https://localhost:9010',
  secure: true // Depends on your needs, could be false.
}).listen(443);
HTTP -> HTTPS (using a PKCS12 client certificate)
//
// Create an HTTP proxy server with an HTTPS target
//
httpProxy.createProxyServer({
  target: {
    protocol: 'https:',
    host: 'my-domain-name',
    port: 443,
    pfx: fs.readFileSync('path/to/certificate.p12'),
    passphrase: 'password',
  },
  changeOrigin: true,
}).listen(8000);

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Proxying WebSockets

You can activate the websocket support for the proxy using ws:true in the options.

//
// Create a proxy server for websockets
//
httpProxy.createServer({
  target: 'ws://localhost:9014',
  ws: true
}).listen(8014);

Also you can proxy the websocket requests just calling the ws(req, socket, head) method.

//
// Setup our server to proxy standard HTTP requests
//
var proxy = new httpProxy.createProxyServer({
  target: {
    host: 'localhost',
    port: 9015
  }
});
var proxyServer = http.createServer(function (req, res) {
  proxy.web(req, res);
});

//
// Listen to the `upgrade` event and proxy the
// WebSocket requests as well.
//
proxyServer.on('upgrade', function (req, socket, head) {
  proxy.ws(req, socket, head);
});

proxyServer.listen(8015);

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Options

httpProxy.createProxyServer supports the following options:

NOTE: options.ws and options.ssl are optional. options.target and options.forward cannot both be missing

If you are using the proxyServer.listen method, the following options are also applicable:

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Listening for proxy events

var httpProxy = require('http-proxy');
// Error example
//
// Http Proxy Server with bad target
//
var proxy = httpProxy.createServer({
  target:'http://localhost:9005'
});

proxy.listen(8005);

//
// Listen for the `error` event on `proxy`.
proxy.on('error', function (err, req, res) {
  res.writeHead(500, {
    'Content-Type': 'text/plain'
  });

  res.end('Something went wrong. And we are reporting a custom error message.');
});

//
// Listen for the `proxyRes` event on `proxy`.
//
proxy.on('proxyRes', function (proxyRes, req, res) {
  console.log('RAW Response from the target', JSON.stringify(proxyRes.headers, true, 2));
});

//
// Listen for the `open` event on `proxy`.
//
proxy.on('open', function (proxySocket) {
  // listen for messages coming FROM the target here
  proxySocket.on('data', hybiParseAndLogMessage);
});

//
// Listen for the `close` event on `proxy`.
//
proxy.on('close', function (res, socket, head) {
  // view disconnected websocket connections
  console.log('Client disconnected');
});

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Shutdown

var proxy = new httpProxy.createProxyServer({
  target: {
    host: 'localhost',
    port: 1337
  }
});

proxy.close();

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Miscellaneous

If you want to handle your own response after receiving the proxyRes, you can do so with selfHandleResponse. As you can see below, if you use this option, you are able to intercept and read the proxyRes but you must also make sure to reply to the res itself otherwise the original client will never receive any data.

Modify response


    var option = {
      target: target,
      selfHandleResponse : true
    };
    proxy.on('proxyRes', function (proxyRes, req, res) {
        var body = [];
        proxyRes.on('data', function (chunk) {
            body.push(chunk);
        });
        proxyRes.on('end', function () {
            body = Buffer.concat(body).toString();
            console.log("res from proxied server:", body);
            res.end("my response to cli");
        });
    });
    proxy.web(req, res, option);

ProxyTable API

A proxy table API is available through this add-on module, which lets you define a set of rules to translate matching routes to target routes that the reverse proxy will talk to.

Test

$ npm test

Logo created by Diego Pasquali

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Contributing and Issues

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License

The MIT License (MIT)

Copyright (c) 2010 - 2016 Charlie Robbins, Jarrett Cruger & the Contributors.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

node-http-proxy (http-party/node-http-proxy)

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14.1K ·GitHub
Node-http-proxy
What is this?node-http-proxy is a programmable HTTP proxying library for Node.js that also supports WebSockets, used to build things like reverse proxies and load balancers.
Is this a standalone proxy server or a library I embed in my own code?It's a library: you call createProxyServer() to get a proxy object with web/ws/listen/close methods, then either call listen() to spin up a standalone server or plug it into your own HTTP server logic.
How do I add it to a project?Install it via npm with `npm install http-proxy --save`, then require it and call httpProxy.createProxyServer({...}) with your target options.
Does it need any extra dependencies to run?It only needs Node.js 8.0.0 or newer; its own runtime dependencies (eventemitter3, requires-port, follow-redirects) are installed automatically via npm.
Does it handle errors between client and target automatically?No — the library does not do any error handling of messages passed between client/proxy or proxy/target, so you're expected to listen for the 'error' event yourself and handle failures.
Who would use this?Node.js developers who need to build reverse proxies, load balancers, or custom request-routing/rewriting logic in front of other HTTP or WebSocket servers.
Can it proxy HTTPS and verify SSL certificates?Yes, you can proxy to/from HTTPS targets and set `secure: true` to validate the target's SSL certificate and avoid self-signed certs.
How do I proxy WebSocket traffic?Set `ws: true` in the proxy options, or call the ws(req, socket, head) method directly to handle incoming WebSocket upgrade requests.
Can I rewrite headers, cookies, or redirect locations through the proxy?Yes — options like changeOrigin, cookieDomainRewrite, cookiePathRewrite, hostRewrite, autoRewrite, and protocolRewrite let you rewrite headers, set-cookie domains/paths, and redirect locations on the fly.
Can I modify the response body before it reaches the client?Yes, using the selfHandleResponse option combined with the proxyRes event you can intercept and modify responses yourself (or use the separate Harmon module for streaming HTML/XML transforms).
What are similar projects?pingora, http-proxy-middleware, nginx, traefik, socket.io, ws, axios, request
Which topics is it in?load-balancer, reverse-proxy, websocket, http, proxy, backend, networking, npm, api, server, nodejs, library
Creator
http-party
Size
1.7 MB
Stars
14.1K
Updated
CommitMay 17Release1.17.0Apr 20
Age
16y
Commits · 90 Days