Node.js proxying made simple. Configure proxy middleware with ease for connect, express, browser-sync and many more.
Powered by the popular Nodejitsu http-proxy
.
Proxy /api
requests to http://www.example.org
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 can be used, along with some extra http-proxy-middleware
options.
💡 Tip: Set the option changeOrigin
to true
for name-based virtual hosted sites.
- Install
- Core concept
- Example
- Context matching
- Options
- Shorthand
- WebSocket
- Working examples
- Recipes
- Compatible servers
- Tests
- Changelog
- License
$ npm install --save-dev http-proxy-middleware
Proxy middleware configuration.
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)
- options.target: target host to proxy to. (protocol + host)
(full list of http-proxy-middleware
configuration options)
// shorthand syntax for the example above:
var apiProxy = proxy('http://www.example.org/api');
More about the shorthand configuration.
An example with express
server.
// 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);
Providing an alternative way to decide which requests should be proxied; In case you are not able to use the server's path
parameter to mount the proxy or when you need more flexibility.
The RFC 3986 path
is be 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 or 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-absoluteproxy('/api/**/*.html', {...})
matches requests ending with.html
in the path of/api
proxy(['/api/**', '/ajax/**'], {...})
combine multiple patternsproxy(['/api/**', '!**/bad.json'], {...})
exclusion
-
custom matching
For full control you can provide a custom function to determine which requests should be proxied or not.
/** * @return {Boolean} */ var filter = function (pathname, req) { return (pathname.match('^/api') && req.method === 'GET'); }; var apiProxy = proxy(filter, {target: 'http://www.example.org'})
-
option.pathRewrite: object/function, rewrite target's url path. Object-keys will be used as RegExp to match paths.
// 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.// 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
.// simple replace function logProvider(provider) { // replace the default console log provider. return require('winston'); }
// 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.
Subscribe to http-proxy events:
-
option.onError: function, subscribe to http-proxy's
error
event for custom error handling.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.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.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.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.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.function onClose(res, socket, head) { // view disconnected websocket connections console.log('Client disconnected'); }
The following options are provided by the underlying http-proxy 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 and 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.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, usecookieDomainRewrite: ""
. - 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.headers: object, adds request headers. (Example:
{host:'www.example.org'}
) - option.proxyTimeout: timeout (in millis) when proxy receives no response from target
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.
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});
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:
app.use('/api', proxy({target:'http://www.example.org', changeOrigin:true}));
app.use
documentation:
- express: http://expressjs.com/en/4x/api.html#app.use
- connect: https://github.com/senchalabs/connect#mount-middleware
// 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');
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.
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'
View and play around with working examples.
- Browser-Sync (example source)
- express (example source)
- connect (example source)
- WebSocket (example source)
View the recipes for common use cases.
http-proxy-middleware
is compatible with the following servers:
- connect
- express
- browser-sync
- lite-server
- grunt-contrib-connect
- grunt-browser-sync
- gulp-connect
- gulp-webserver
Sample implementations can be found in the server recipes.
Run the test suite:
# install dependencies
$ npm install
# linting
$ npm run lint
# unit tests
$ npm test
# code coverage
$ npm run cover
The MIT License (MIT)
Copyright (c) 2015-2017 Steven Chim