# global-agent [![GitSpo Mentions](https://gitspo.com/badges/mentions/gajus/global-agent?style=flat-square)](https://gitspo.com/mentions/gajus/global-agent) [![Travis build status](http://img.shields.io/travis/gajus/global-agent/master.svg?style=flat-square)](https://travis-ci.org/gajus/global-agent) [![Coveralls](https://img.shields.io/coveralls/gajus/global-agent.svg?style=flat-square)](https://coveralls.io/github/gajus/global-agent) [![NPM version](http://img.shields.io/npm/v/global-agent.svg?style=flat-square)](https://www.npmjs.org/package/global-agent) [![Canonical Code Style](https://img.shields.io/badge/code%20style-canonical-blue.svg?style=flat-square)](https://github.com/gajus/canonical) [![Twitter Follow](https://img.shields.io/twitter/follow/kuizinas.svg?style=social&label=Follow)](https://twitter.com/kuizinas) Global HTTP/HTTPS proxy configurable using environment variables. * [Usage](#usage) * [Setup proxy using `global-agent/bootstrap`](#setup-proxy-using-global-agentbootstrap) * [Setup proxy using `bootstrap` routine](#setup-proxy-using-bootstrap-routine) * [Runtime configuration](#runtime-configuration) * [Exclude URLs](#exclude-urls) * [Enable logging](#enable-logging) * [API](#api) * [`createGlobalProxyAgent`](#createglobalproxyagent) * [Environment variables](#environment-variables) * [`global.GLOBAL_AGENT`](#globalglobal_agent) * [Supported libraries](#supported-libraries) * [FAQ](#faq) * [What is the reason `global-agent` overrides explicitly configured HTTP(S) agent?](#what-is-the-reason-global-agent-overrides-explicitly-configured-https-agent) * [What is the reason `global-agent/bootstrap` does not use `HTTP_PROXY`?](#what-is-the-reason-global-agentbootstrap-does-not-use-http_proxy) * [What is the difference from `global-tunnel` and `tunnel`?](#what-is-the-difference-from-global-tunnel-and-tunnel) ## Usage ### Setup proxy using `global-agent/bootstrap` 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 ``` ### Setup proxy using `bootstrap` routine Instead of importing a self-initialising script with side-effects as demonstrated in the [setup proxy using `global-agent/bootstrap`](#setup-proxy-using-global-agentbootstrap) 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 globalTunner 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(); } ``` ### Setup proxy using `createGlobalProxyAgent` 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`. ### Runtime configuration `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. ### Exclude URLs 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. ### Separate proxy for HTTPS 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. ### Enable logging `global-agent` is using [`roarr`](https://www.npmjs.com/package/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`](https://github.com/gajus/roarr-cli) program to pretty-print the logs. ## API ### `createGlobalProxyAgent` ```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; ``` ### Environment variables |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| ### `global.GLOBAL_AGENT` `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](#exclude-urls).| ## Supported libraries `global-agent` works with all libraries that internally use [`http.request`](https://nodejs.org/api/http.html#http_http_request_options_callback). `global-agent` has been tested to work with: * [`got`](https://www.npmjs.com/package/got) * [`axios`](https://www.npmjs.com/package/axios) * [`request`](https://www.npmjs.com/package/axios) ## FAQ ### What is the reason `global-agent` overrides explicitly configured HTTP(S) agent? By default, `global-agent` overrides [`agent` property](https://nodejs.org/api/http.html#http_http_request_options_callback) 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`](https://github.com/stripe/stripe-node/blob/e542902dd8fbe591fe3c3ce07a7e89d1d60e4cf7/lib/StripeResource.js#L11-L12)). 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`. ### What is the reason `global-agent/bootstrap` does not use `HTTP_PROXY`? Some libraries (e.g. [`request`](https://npmjs.org/package/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. ### What is the difference from `global-tunnel` and `tunnel`? [`global-tunnel`](https://github.com/salesforce/global-tunnel) (including [`global-tunnel-ng`](https://github.com/np-maintain/global-tunnel) and [`tunnel`](https://npmjs.com/package/tunnel)) are designed to support legacy Node.js versions. They use various [workarounds](https://github.com/koichik/node-tunnel/blob/5fb2fb424788597146b7be6729006cad1cf9e9a8/lib/tunnel.js#L134-L144) and rely on [monkey-patching `http.request`, `http.get`, `https.request` and `https.get` methods](https://github.com/np-maintain/global-tunnel/blob/51413dcf0534252b5049ec213105c7063ccc6367/index.js#L302-L338). In contrast, `global-agent` supports Node.js v10 and above, and does not implements workarounds for the older Node.js versions.