global-tunnel

global-tunnel

Configures the global http and https agents to use an upstream HTTP proxy.

Works transparently to tunnel modules that use node's default http.request() method as well as the popular request module.

Usage

To make all HTTP and HTTPS connections go through an outbound HTTP proxy:

var globalTunnel = require('global-tunnel');

globalTunnel.initialize({
  host: '10.0.0.10',
  port: 8080,
  sockets: 50 // optional pool size for each http and https
});

This will use the CONNECT method for HTTPS requests and absolute-URIs for HTTP requests, which is how many network proxies are configured.

Optionally, to tear-down the global agent and restore node's default global agents:

globalTunnel.end();

Any active connections will be allowed to run to completion, but new connections will use the default global agents.

Advanced Usage

Options

The complete list of options to globalTunnel.initialize:

• host - the hostname or IP of the HTTP proxy to use
• port - the TCP port to use on that proxy
• tunnel (optional) controls what protocols use the CONNECT method. It has three possible values (strings):
  • neither - don't use CONNECT; just use absolute URIs
  • https - (the default) only use CONNECT for HTTPS requests
  • both - use CONNECT for both HTTP and HTTPS requests
• protocol - the protocol that the proxy speaks, either http: or https:.
• sockets - (optional) maximum number of TCP sockets to use in each pool. There are two pools: one for HTTP and one for HTTPS. Uses node's default (5) if falsy.

Variations

Here's a few interesting variations on the basic config.

Absolute URI Proxies

Another common proxy configuration is one that expects clients to use an absolute URI for the Request-URI for all HTTP and HTTPS requests. This is common for networks that use a proxy for security scanning and access control.

What does this mean? It means that instead of ...

GET / HTTP/1.1
Host: example.com

... your proxy expects ...

GET https://example.com/ HTTP/1.1

You'll need to specify tunnel: 'neither' if this is the case. If the proxy speaks HTTP (i.e. the connection from node --> proxy is not encrypted):

globalTunnel.initialize({
  tunnel: 'neither',
  host: '10.0.0.10',
  port: 3128
});

or, if the proxy speaks HTTPS to your app instead:

globalTunnel.initialize({
  tunnel: 'neither',
  protocol: 'https:'
  host: '10.0.0.10',
  port: 3129
});

Always-CONNECT Proxies

If the proxy expects you to use the CONNECT method for both HTTP and HTTPS requests, you'll need the tunnel: 'both' option.

What does this mean? It means that instead of ...

GET https://example.com/ HTTP/1.1

... your proxy expects ...

CONNECT example.com:443 HTTP/1.1

Be sure to set the protocol: option based on what protocol the proxy speaks.

globalTunnel.initialize({
  tunnel: 'both',
  host: '10.0.0.10',
  port: 3130
});

HTTPS configuration

EXPERIMENTAL

If tunnelling both protocols, you can use different HTTPS client configurations for the two phases of the connection.

globalTunnel.initialize({
  tunnel: 'both',
  protocol: 'https:'
  host: '10.0.0.10',
  port: 3130,
  proxyHttpsConfig: {
    // use this config for app -> proxy
  },
  originHttpsConfig: {
    // use this config for proxy -> origin
  }
});

Auto-Config

The http_proxy environment variable will be used if the first parameter to globalTunnel.initialize is null or an empty object.

process.env.http_proxy = 'http://10.0.0.1:3129';
globalTunnel.initialize();

Compatibility

Any module that doesn't specify an explicit agent: option to http.request will also work with global-tunnel.

The unit tests for this module verify that the popular request module works with global-tunnel active.

For untested modules, it's recommended that you load and initialize global-tunnel first. This way, any copies of http.globalAgent will point to the right thing.

Contributing

If you'd like to contribute to or modify global-tunnel, here's a quick guide to get you started.

Development Dependencies

• node.js >= 0.10

Set-Up

Download via GitHub and install npm dependencies:

git clone [e-mail]:goinstant/global-tunnel.git
cd global-tunnel
npm install

Testing

Testing is with the mocha framework. Tests are located in the test/ directory.

To run the tests:

npm test

Support

Email GoInstant Support or stop by #goinstant on freenode.

For responsible disclosures, email GoInstant Security.

To file a bug or propose a patch, please use github directly.

Legal

© 2014 GoInstant Inc., a salesforce.com company

Licensed under the BSD 3-clause license.