@kldzj/proxy-protocol

proxy-protocol

Add PROXY v1 or v2 support to net, http, https, spdy and http2 servers. IPv4 and IPv6 protocols supported

History

This module is a TypeScript rewrite of original proxywrap by Josh Dague and José Moreira.

What's the purpose of this module?

This module wraps node's various Server interfaces so that they are compatible with the PROXY protocol. It automatically parses the PROXY headers and resets socket.remoteAddress and socket.remotePort so that they have the correct values.

This module is especially useful if you need to get the client IP address when you're behind an AWS ELB in TCP mode.

In HTTP or HTTPS mode (aka SSL termination at ELB), the ELB inserts X-Forwarded-For headers for you. However, in TCP mode, the ELB can't understand the underlying protocol, so you lose the client's IP address. With the PROXY protocol and this module, you're able to retain the client IP address with any protocol.

In order for this module to work with ELB, you must enable the PROXY protocol on your ELB (or whatever proxy your app is behind).

Compability

This module is only compatible with LTS and latest stable versions of node.

Installing

npm install --save @kldzj/proxy-protocol

Usage

proxywrap is a drop-in replacement. Here's a simple Express app:

var http = require('http');
var proxiedHttp = require('@kldzj/proxy-protocol').proxy(http);
var express = require('express');
var app = express();

// instead of http.createServer(app)
var srv = proxiedHttp.createServer(app).listen(80);

app.get('/', (req, res) => {
  res.send('IP = ' + req.connection.remoteAddress + ':' + req.connection.remotePort);
});

The magic happens in the proxywrap.proxy() call. It wraps the module's Server constructor and handles a bunch of messy details for you.

You can do the same with net (raw TCP streams), https, and spdy. It will probably work with other modules that follow the same pattern, but none have been tested.

Note: If you're wrapping node-spdy, its exports are a little strange:

var proxiedSpdy = require('@kldzj/proxy-protocol').proxy(require('spdy').server);

This also adds to all your sockets the properties:

• socket.clientAddress - The IP Address that connected to your PROXY.
• socket.clientPort - The Port used by who connected to your PROXY.
• socket.proxyAddress - The IP Address exposed on Client <-> Proxy side.
• socket.proxyPort - The Port exposed on Client <-> Proxy side. Usefull for detecting SSL on AWS ELB.
• socket.remoteAddress [optional] - Same as socket.clientAddress, used for compability proposes.
• socket.remotePort [optional] - Same as socket.clientPort, used for compability proposes.

Warning: By default, all traffic to your proxied server MUST use the PROXY protocol. If the first five bytes received aren't PROXY, the connection will be dropped. Obviously, the node server accepting PROXY connections should not be exposed directly to the internet; only the proxy (whether ELB, HAProxy, or something else) should be able to connect to node.

API

proxy(Server[, options])

Wraps something that inherits from the net module, exposing a Server and createServer. Returns the same module patched to support the PROXY protocol.

Options:

• strict (default true): Incoming connections MUST use the PROXY protocol. If the first five bytes received aren't PROXY, the connection will be dropped. Disabling this option will allow connections that don't use the PROXY protocol (so long as the first bytes sent aren't PROXY). Disabling this option poses a security risk; it should be enabled in production.

• ignoreStrictExceptions (default false): strict shutdowns your process with an error attached, meaning that if it isn't being caught on socket's error event, node will terminate process with an uncaughtException. This option tells strict methods to destroy sockets without providing the exception, so node ignores it. See #11 for more info.

• overrideRemote (default true): findhit-proxywrap overrides socket.remoteAddress and socket.remotePort for compability proposes. If you set this as false, your socket.remoteAddress and socket.remotePort will have the Address and Port of your load-balancer or whatever you are using behind your app. You can also access client's Address and Port by using socket.clientAddress and socket.clientPort.

Thanks

Thanks to all contibuters and special thanks to Josh Dague for creating original proxywrap.