global-agent


Global HTTP/HTTPS proxy configurable using environment variables.

* Usage
* Setup proxy using global-agent/bootstrap
* Setup proxy using bootstrap routine
* Runtime configuration
* Exclude URLs
* Enable logging
* API
* createGlobalProxyAgent
* Environment variables
* global.GLOBAL_AGENT
* Supported libraries
* FAQ
* What is the reason global-agent overrides explicitly configured HTTP(S) agent?
* What is the reason global-agent/bootstrap does not use HTTP_PROXY?
* What is the difference from global-tunnel and tunnel?

Usage

$3

To configure HTTP proxy:

1. Import global-agent/bootstrap.
1. Export HTTP proxy address as GLOBAL_AGENT_HTTP_PROXY environment variable.

Code:

``js
import 'global-agent/bootstrap';

// or:
// import {bootstrap} from 'global-agent';
// bootstrap();

`

Bash:

`bash
$ export GLOBAL_AGENT_HTTP_PROXY=http://127.0.0.1:8080

`

Alternatively, you can preload module using Node.js --require, -r configuration, e.g.

`bash
$ export GLOBAL_AGENT_HTTP_PROXY=http://127.0.0.1:8080
$ node -r 'global-agent/bootstrap' your-script.js

`

$3

Instead of importing a self-initialising script with side-effects as demonstrated in the setup proxy using global-agent/bootstrap documentation, you can import bootstrap routine and explicitly evaluate the bootstrap logic, e.g.

`js
import {
bootstrap
} from 'global-agent';

bootstrap();

`

This is useful if you need to conditionally bootstrap global-agent, e.g.

`js
import {
bootstrap
} from 'global-agent';
import globalTunnel from 'global-tunnel-ng';

const MAJOR_NODEJS_VERSION = parseInt(process.version.slice(1).split('.')[0], 10);

if (MAJOR_NODEJS_VERSION >= 10) {
// global-agent works with Node.js v10 and above.
bootstrap();
} else {
// global-tunnel-ng works only with Node.js v10 and below.
globalTunnel.initialize();
}

`

$3

If you do not want to use global.GLOBAL_AGENT variable, then you can use createGlobalProxyAgent to instantiate a controlled instance of global-agent, e.g.

`js
import {
createGlobalProxyAgent
} from 'global-agent';

const globalProxyAgent = createGlobalProxyAgent();

`

Unlike bootstrap routine, createGlobalProxyAgent factory does not create global.GLOBAL_AGENT variable and does not guard against multiple initializations of global-agent. The result object of createGlobalProxyAgent is equivalent to global.GLOBAL_AGENT.

$3

global-agent/bootstrap script copies process.env.GLOBAL_AGENT_HTTP_PROXY value to global.GLOBAL_AGENT.HTTP_PROXY and continues to use the latter variable.

You can override the global.GLOBAL_AGENT.HTTP_PROXY value at runtime to change proxy behaviour, e.g.

`js
http.get('http://127.0.0.1:8000');

global.GLOBAL_AGENT.HTTP_PROXY = 'http://127.0.0.1:8001';

http.get('http://127.0.0.1:8000');

global.GLOBAL_AGENT.HTTP_PROXY = 'http://127.0.0.1:8002';

`

The first HTTP request is going to use http://127.0.0.1:8001 proxy and the secord request is going to use http://127.0.0.1:8002.

All global-agent configuration is available under global.GLOBAL_AGENT namespace.

$3

The GLOBAL_AGENT_NO_PROXY environment variable specifies a pattern of URLs that should be excluded from proxying. GLOBAL_AGENT_NO_PROXY value is a comma-separated list of domain names. Asterisks can be used as wildcards, e.g.

`bash
export GLOBAL_AGENT_NO_PROXY='*.foo.com,baz.com'

`

says to contact all machines with the 'foo.com' TLD and 'baz.com' domains directly.

$3

The environment variable GLOBAL_AGENT_HTTPS_PROXY can be set to specify a separate proxy for HTTPS requests. When this variable is not set GLOBAL_AGENT_HTTP_PROXY is used for both HTTP and HTTPS requests.

$3

global-agent is using roarr logger to log HTTP requests and response (HTTP status code and headers), e.g.

`json
{"context":{"program":"global-agent","namespace":"Agent","logLevel":10,"destination":"http://gajus.com","proxy":"http://127.0.0.1:8076"},"message":"proxying request","sequence":1,"time":1556269669663,"version":"1.0.0"}
{"context":{"program":"global-agent","namespace":"Agent","logLevel":10,"headers":{"content-type":"text/plain","content-length":"2","date":"Fri, 26 Apr 2019 12:07:50 GMT","connection":"close"},"requestId":6,"statusCode":200},"message":"proxying response","sequence":2,"time":1557133856955,"version":"1.0.0"}

`

Export ROARR_LOG=true environment variable to enable log printing to stdout.

Use roarr-cli program to pretty-print the logs.

API

$3

`js
/**
* @property environmentVariableNamespace Defines namespace of HTTP_PROXY, HTTPS_PROXY and NO_PROXY environment variables. (Default: GLOBAL_AGENT_)
* @property forceGlobalAgent Forces to use global-agent HTTP(S) agent even when request was explicitly constructed with another agent. (Default: true)
* @property socketConnectionTimeout Destroys socket if connection is not established within the timeout. (Default: 60000)
*/
type ProxyAgentConfigurationInputType = {|
+environmentVariableNamespace?: string,
+forceGlobalAgent?: boolean,
+socketConnectionTimeout?: number,
|};

(configurationInput: ProxyAgentConfigurationInputType) => ProxyAgentConfigurationType;

`

$3

|Name|Description|Default|
|---|---|---|
|GLOBAL_AGENT_ENVIRONMENT_VARIABLE_NAMESPACE|Defines namespace of HTTP_PROXY, HTTPS_PROXY and NO_PROXY environment variables.|GLOBAL_AGENT_|
|GLOBAL_AGENT_FORCE_GLOBAL_AGENT|Forces to use global-agent HTTP(S) agent even when request was explicitly constructed with another agent.|true|
|GLOBAL_AGENT_SOCKET_CONNECTION_TIMEOUT|Destroys socket if connection is not established within the timeout.|60000|
|${NAMESPACE}_HTTP_PROXY|Sets the initial proxy controller HTTP_PROXY value.|N/A|
|${NAMESPACE}_HTTPS_PROXY|Sets the initial proxy controller HTTPS_PROXY value.|N/A|
|${NAMESPACE}_NO_PROXY|Sets the initial proxy controller NO_PROXY value.|N/A|

$3

global.GLOBAL_AGENT is initialized by bootstrap routine.

global.GLOBAL_AGENT has the following properties:

|Name|Description|Configurable|
|---|---|---|
|HTTP_PROXY|Yes|Sets HTTP proxy to use.|
|HTTPS_PROXY|Yes|Sets a distinct proxy to use for HTTPS requests.|
|NO_PROXY|Yes|Specifies a pattern of URLs that should be excluded from proxying. See Exclude URLs.|

Supported libraries

global-agent works with all libraries that internally use http.request.

global-agent has been tested to work with:

* got
* axios
* request

FAQ

$3

By default, global-agent overrides agent property of any HTTP request, even if agent property was explicitly set when constructing a HTTP request. This behaviour allows to intercept requests of libraries that use a custom instance of an agent per default (e.g. Stripe SDK uses an http(s).globalAgent instance pre-configured with keepAlive: true).

This behaviour can be disabled with GLOBAL_AGENT_FORCE_GLOBAL_AGENT=false environment variable. When disabled, then global-agent will only set agent property when it is not already defined or if agent is an instance of http(s).globalAgent.

$3

Some libraries (e.g. request) change their behaviour when HTTP_PROXY environment variable is present. Using a namespaced environment variable prevents conflicting library behaviour.

You can override this behaviour by configuring GLOBAL_AGENT_ENVIRONMENT_VARIABLE_NAMESPACE variable, e.g.

`bash
$ export GLOBAL_AGENT_ENVIRONMENT_VARIABLE_NAMESPACE=

`

Now script initialized using global-agent/bootstrap will use HTTP_PROXY, HTTPS_PROXY and NO_PROXY environment variables.

$3

global-tunnel (including global-tunnel-ng and tunnel) are designed to support legacy Node.js versions. They use various workarounds and rely on monkey-patching http.request, http.get, https.request and https.get methods.

In contrast, global-agent` supports Node.js v10 and above, and does not implements workarounds for the older Node.js versions.