# http-proxy-middleware [![Build Status](https://img.shields.io/travis/chimurai/http-proxy-middleware/master.svg?style=flat-square)](https://travis-ci.org/chimurai/http-proxy-middleware) [![Coveralls](https://img.shields.io/coveralls/chimurai/http-proxy-middleware.svg?style=flat-square)](https://coveralls.io/r/chimurai/http-proxy-middleware) [![dependency Status](https://img.shields.io/david/chimurai/http-proxy-middleware.svg?style=flat-square)](https://david-dm.org/chimurai/http-proxy-middleware#info=dependencies) [![dependency Status](https://snyk.io/test/npm/http-proxy-middleware/badge.svg)](https://snyk.io/test/npm/http-proxy-middleware) [![code style: prettier](https://img.shields.io/badge/code_style-prettier-ff69b4.svg?style=flat-square)](https://github.com/prettier/prettier) Node.js proxying made simple. Configure proxy middleware with ease for [connect](https://github.com/senchalabs/connect), [express](https://github.com/strongloop/express), [browser-sync](https://github.com/BrowserSync/browser-sync) and [many more](#compatible-servers). Powered by the popular Nodejitsu [`http-proxy`](https://github.com/nodejitsu/node-http-proxy). [![GitHub stars](https://img.shields.io/github/stars/nodejitsu/node-http-proxy.svg?style=social\&label=Star)](https://github.com/nodejitsu/node-http-proxy) ## TL;DR Proxy `/api` requests to `http://www.example.org` ```javascript var express = require('express') var proxy = require('http-proxy-middleware') var app = express() app.use('/api', proxy({ target: 'http://www.example.org', changeOrigin: true })) app.listen(3000) // http://localhost:3000/api/foo/bar -> http://www.example.org/api/foo/bar ``` *All* `http-proxy` [options](https://github.com/nodejitsu/node-http-proxy#options) can be used, along with some extra `http-proxy-middleware` [options](#options). :bulb: **Tip:** Set the option `changeOrigin` to `true` for [name-based virtual hosted sites](http://en.wikipedia.org/wiki/Virtual_hosting#Name-based). ## Table of Contents * [Install](#install) * [Core concept](#core-concept) * [Example](#example) * [Context matching](#context-matching) * [Options](#options) * [http-proxy-middleware options](#http-proxy-middleware-options) * [http-proxy events](#http-proxy-events) * [http-proxy options](#http-proxy-options) * [Shorthand](#shorthand) * [app.use(path, proxy)](#appusepath-proxy) * [WebSocket](#websocket) * [External WebSocket upgrade](#external-websocket-upgrade) * [Working examples](#working-examples) * [Recipes](#recipes) * [Compatible servers](#compatible-servers) * [Tests](#tests) * [Changelog](#changelog) * [License](#license) ## Install ```javascript $ npm install --save-dev http-proxy-middleware ``` ## Core concept Proxy middleware configuration. #### proxy(\[context,] config) ```javascript var proxy = require('http-proxy-middleware') var apiProxy = proxy('/api', { target: 'http://www.example.org' }) // \____/ \_____________________________/ // | | // context options // 'apiProxy' is now ready to be used as middleware in a server. ``` * **context**: Determine which requests should be proxied to the target host. (more on [context matching](#context-matching)) * **options.target**: target host to proxy to. *(protocol + host)* (full list of [`http-proxy-middleware` configuration options](#options)) #### proxy(uri \[, config]) ```javascript // shorthand syntax for the example above: var apiProxy = proxy('http://www.example.org/api') ``` More about the [shorthand configuration](#shorthand). ## Example An example with `express` server. ```javascript // include dependencies var express = require('express') var proxy = require('http-proxy-middleware') // proxy middleware options var options = { target: 'http://www.example.org', // target host changeOrigin: true, // needed for virtual hosted sites ws: true, // proxy websockets pathRewrite: { '^/api/old-path': '/api/new-path', // rewrite path '^/api/remove/path': '/path' // remove base path }, router: { // when request.headers.host == 'dev.localhost:3000', // override target 'http://www.example.org' to 'http://localhost:8000' 'dev.localhost:3000': 'http://localhost:8000' } } // create the proxy (without context) var exampleProxy = proxy(options) // mount `exampleProxy` in web server var app = express() app.use('/api', exampleProxy) app.listen(3000) ``` ## Context matching Providing an alternative way to decide which requests should be proxied; In case you are not able to use the server's [`path` parameter](http://expressjs.com/en/4x/api.html#app.use) to mount the proxy or when you need more flexibility. [RFC 3986 `path`](https://tools.ietf.org/html/rfc3986#section-3.3) is used for context matching. ``` foo://example.com:8042/over/there?name=ferret#nose \_/ \______________/\_________/ \_________/ \__/ | | | | | scheme authority path query fragment ``` * **path matching** * `proxy({...})` - matches any path, all requests will be proxied. * `proxy('/', {...})` - matches any path, all requests will be proxied. * `proxy('/api', {...})` - matches paths starting with `/api` * **multiple path matching** * `proxy(['/api', '/ajax', '/someotherpath'], {...})` * **wildcard path matching** For fine-grained control you can use wildcard matching. Glob pattern matching is done by *micromatch*. Visit [micromatch](https://www.npmjs.com/package/micromatch) or [glob](https://www.npmjs.com/package/glob) for more globbing examples. * `proxy('**', {...})` matches any path, all requests will be proxied. * `proxy('**/*.html', {...})` matches any path which ends with `.html` * `proxy('/*.html', {...})` matches paths directly under path-absolute * `proxy('/api/**/*.html', {...})` matches requests ending with `.html` in the path of `/api` * `proxy(['/api/**', '/ajax/**'], {...})` combine multiple patterns * `proxy(['/api/**', '!**/bad.json'], {...})` exclusion **Note**: In multiple path matching, you cannot use string paths and wildcard paths together. * **custom matching** For full control you can provide a custom function to determine which requests should be proxied or not. ```javascript /** * @return {Boolean} */ var filter = function(pathname, req) { return pathname.match('^/api') && req.method === 'GET' } var apiProxy = proxy(filter, { target: 'http://www.example.org' }) ``` ## Options ### http-proxy-middleware options * **option.pathRewrite**: object/function, rewrite target's url path. Object-keys will be used as *RegExp* to match paths. ```javascript // rewrite path pathRewrite: {'^/old/api' : '/new/api'} // remove path pathRewrite: {'^/remove/api' : ''} // add base path pathRewrite: {'^/' : '/basepath/'} // custom rewriting pathRewrite: function (path, req) { return path.replace('/api', '/base/api') } ``` * **option.router**: object/function, re-target `option.target` for specific requests. ```javascript // Use `host` and/or `path` to match requests. First match will be used. // The order of the configuration matters. router: { 'integration.localhost:3000' : 'http://localhost:8001', // host only 'staging.localhost:3000' : 'http://localhost:8002', // host only 'localhost:3000/api' : 'http://localhost:8003', // host + path '/rest' : 'http://localhost:8004' // path only } // Custom router function router: function(req) { return 'http://localhost:8004'; } ``` * **option.logLevel**: string, \['debug', 'info', 'warn', 'error', 'silent']. Default: `'info'` * **option.logProvider**: function, modify or replace log provider. Default: `console`. ```javascript // simple replace function logProvider(provider) { // replace the default console log provider. return require('winston') } ``` ```javascript // verbose replacement function logProvider(provider) { var logger = new (require('winston')).Logger() var myCustomProvider = { log: logger.log, debug: logger.debug, info: logger.info, warn: logger.warn, error: logger.error } return myCustomProvider } ``` * (DEPRECATED) **option.proxyHost**: Use `option.changeOrigin = true` instead. * (DEPRECATED) **option.proxyTable**: Use `option.router` instead. ### http-proxy events Subscribe to [http-proxy events](https://github.com/nodejitsu/node-http-proxy#listening-for-proxy-events): * **option.onError**: function, subscribe to http-proxy's `error` event for custom error handling. ```javascript function onError(err, req, res) { res.writeHead(500, { 'Content-Type': 'text/plain' }) res.end( 'Something went wrong. And we are reporting a custom error message.' ) } ``` * **option.onProxyRes**: function, subscribe to http-proxy's `proxyRes` event. ```javascript function onProxyRes(proxyRes, req, res) { proxyRes.headers['x-added'] = 'foobar' // add new header to response delete proxyRes.headers['x-removed'] // remove header from response } ``` * **option.onProxyReq**: function, subscribe to http-proxy's `proxyReq` event. ```javascript function onProxyReq(proxyReq, req, res) { // add custom header to request proxyReq.setHeader('x-added', 'foobar') // or log the req } ``` * **option.onProxyReqWs**: function, subscribe to http-proxy's `proxyReqWs` event. ```javascript function onProxyReqWs(proxyReq, req, socket, options, head) { // add custom header proxyReq.setHeader('X-Special-Proxy-Header', 'foobar') } ``` * **option.onOpen**: function, subscribe to http-proxy's `open` event. ```javascript function onOpen(proxySocket) { // listen for messages coming FROM the target here proxySocket.on('data', hybiParseAndLogMessage) } ``` * **option.onClose**: function, subscribe to http-proxy's `close` event. ```javascript function onClose(res, socket, head) { // view disconnected websocket connections console.log('Client disconnected') } ``` ### http-proxy options The following options are provided by the underlying [http-proxy](https://github.com/nodejitsu/node-http-proxy#options) library. * **option.target**: url string to be parsed with the url module * **option.forward**: url string to be parsed with the url module * **option.agent**: object to be passed to http(s).request (see Node's [https agent](http://nodejs.org/api/https.html#https_class_https_agent) and [http agent](http://nodejs.org/api/http.html#http_class_http_agent) objects) * **option.ssl**: object to be passed to https.createServer() * **option.ws**: true/false: if you want to proxy websockets * **option.xfwd**: true/false, adds x-forward headers * **option.secure**: true/false, if you want to verify the SSL Certs * **option.toProxy**: true/false, passes the absolute URL as the `path` (useful for proxying to proxies) * **option.prependPath**: true/false, Default: true - specify whether you want to prepend the target's path to the proxy path * **option.ignorePath**: true/false, Default: false - specify whether you want to ignore the proxy path of the incoming request (note: you will have to append / manually if required). * **option.localAddress** : Local interface string to bind for outgoing connections * **option.changeOrigin**: true/false, Default: false - changes the origin of the host header to the target URL * **option.preserveHeaderKeyCase**: true/false, Default: false - specify whether you want to keep letter case of response header key * **option.auth** : Basic authentication i.e. 'user:password' to compute an Authorization header. * **option.hostRewrite**: rewrites the location hostname on (301/302/307/308) redirects. * **option.autoRewrite**: rewrites the location host/port on (301/302/307/308) redirects based on requested host/port. Default: false. * **option.protocolRewrite**: rewrites the location protocol on (301/302/307/308) redirects to 'http' or 'https'. Default: null. * **option.cookieDomainRewrite**: rewrites domain of `set-cookie` headers. Possible values: * `false` (default): disable cookie rewriting * String: new domain, for example `cookieDomainRewrite: "new.domain"`. To remove the domain, use `cookieDomainRewrite: ""`. * Object: mapping of domains to new domains, use `"*"` to match all domains.\ For example keep one domain unchanged, rewrite one domain and remove other domains: ``` cookieDomainRewrite: { "unchanged.domain": "unchanged.domain", "old.domain": "new.domain", "*": "" } ``` * **option.cookiePathRewrite**: rewrites path of `set-cookie` headers. Possible values: * `false` (default): disable cookie rewriting * String: new path, for example `cookiePathRewrite: "/newPath/"`. To remove the path, use `cookiePathRewrite: ""`. To set path to root use `cookiePathRewrite: "/"`. * Object: mapping of paths to new paths, use `"*"` to match all paths. For example, to keep one path unchanged, rewrite one path and remove other paths: ``` cookiePathRewrite: { "/unchanged.path/": "/unchanged.path/", "/old.path/": "/new.path/", "*": "" } ``` * **option.headers**: object, adds [request headers](https://en.wikipedia.org/wiki/List_of_HTTP_header_fields#Request_fields). (Example: `{host:'www.example.org'}`) * **option.proxyTimeout**: timeout (in millis) when proxy receives no response from target * **option.timeout**: timeout (in millis) for incoming requests * **option.followRedirects**: true/false, Default: false - specify whether you want to follow redirects * **option.selfHandleResponse** true/false, if set to true, none of the webOutgoing passes are called and it's your responsibility to appropriately return the response by listening and acting on the `proxyRes` event * **option.buffer**: stream of data to send as the request body. Maybe you have some middleware that consumes the request stream before proxying it on e.g. If you read the body of a request into a field called 'req.rawbody' you could restream this field in the buffer option: ``` 'use strict'; const streamify = require('stream-array'); const HttpProxy = require('http-proxy'); const proxy = new HttpProxy(); module.exports = (req, res, next) => { proxy.web(req, res, { target: 'http://localhost:4003/', buffer: streamify(req.rawBody) }, next); }; ``` ## Shorthand Use the shorthand syntax when verbose configuration is not needed. The `context` and `option.target` will be automatically configured when shorthand is used. Options can still be used if needed. ```javascript proxy('http://www.example.org:8000/api') // proxy('/api', {target: 'http://www.example.org:8000'}); proxy('http://www.example.org:8000/api/books/*/**.json') // proxy('/api/books/*/**.json', {target: 'http://www.example.org:8000'}); proxy('http://www.example.org:8000/api', { changeOrigin: true }) // proxy('/api', {target: 'http://www.example.org:8000', changeOrigin: true}); ``` ### app.use(path, proxy) If you want to use the server's `app.use` `path` parameter to match requests; Create and mount the proxy without the http-proxy-middleware `context` parameter: ```javascript app.use('/api', proxy({ target: 'http://www.example.org', changeOrigin: true })) ``` `app.use` documentation: * express: * connect: ## WebSocket ```javascript // verbose api proxy('/', { target: 'http://echo.websocket.org', ws: true }) // shorthand proxy('http://echo.websocket.org', { ws: true }) // shorter shorthand proxy('ws://echo.websocket.org') ``` ### External WebSocket upgrade In the previous WebSocket examples, http-proxy-middleware relies on a initial http request in order to listen to the http `upgrade` event. If you need to proxy WebSockets without the initial http request, you can subscribe to the server's http `upgrade` event manually. ```javascript var wsProxy = proxy('ws://echo.websocket.org', { changeOrigin: true }) var app = express() app.use(wsProxy) var server = app.listen(3000) server.on('upgrade', wsProxy.upgrade) // <-- subscribe to http 'upgrade' ``` ## Working examples View and play around with [working examples](https://github.com/chimurai/http-proxy-middleware/tree/master/examples). * Browser-Sync ([example source](https://github.com/chimurai/http-proxy-middleware/tree/master/examples/browser-sync/index.js)) * express ([example source](https://github.com/chimurai/http-proxy-middleware/tree/master/examples/express/index.js)) * connect ([example source](https://github.com/chimurai/http-proxy-middleware/tree/master/examples/connect/index.js)) * WebSocket ([example source](https://github.com/chimurai/http-proxy-middleware/tree/master/examples/websocket/index.js)) ## Recipes View the [recipes](https://github.com/chimurai/http-proxy-middleware/tree/master/recipes) for common use cases. ## Compatible servers `http-proxy-middleware` is compatible with the following servers: * [connect](https://www.npmjs.com/package/connect) * [express](https://www.npmjs.com/package/express) * [browser-sync](https://www.npmjs.com/package/browser-sync) * [lite-server](https://www.npmjs.com/package/lite-server) * [grunt-contrib-connect](https://www.npmjs.com/package/grunt-contrib-connect) * [grunt-browser-sync](https://www.npmjs.com/package/grunt-browser-sync) * [gulp-connect](https://www.npmjs.com/package/gulp-connect) * [gulp-webserver](https://www.npmjs.com/package/gulp-webserver) Sample implementations can be found in the [server recipes](https://github.com/chimurai/http-proxy-middleware/tree/master/recipes/servers.md). ## Tests Run the test suite: ```bash # install dependencies $ npm install # linting $ npm run lint # unit tests $ npm test # code coverage $ npm run cover ``` ## Changelog * [View changelog](https://github.com/chimurai/http-proxy-middleware/blob/master/CHANGELOG.md) ## License The MIT License (MIT) Copyright (c) 2015-2018 Steven Chim --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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