koa-http2-proxy
Configure http2-proxy middleware with ease for koa.
Based on http-proxy-middleware.
TL;DR
Proxy requests to http://www.example.org
var Koa = ;var proxy = ;var app = ; // responseapp; app; // http://localhost:3000/foo/bar -> http://www.example.org/foo/bar
💡 Tip: Set the option changeOrigin
to true
for name-based virtual hosted sites.
Table of Contents
Install
$ npm install --save-dev koa-http2-proxy
Core concept
Proxy middleware configuration.
proxy([context,] config)
var proxy = ; var apiProxy = ;// \____/ \_____________________________/// | |// 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 koa-http2-proxy
configuration options)
proxy(uri [, config])
// shorthand syntax for the example above:var apiProxy = ;
More about the shorthand configuration.
Example
// include dependenciesvar Koa = ;var proxy = ; // proxy middleware optionsvar options = target: 'http://www.example.org' // target host 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 = ; // mount `exampleProxy` in web servervar app = ;app;app;
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 to mount the proxy or when you need more flexibility.
RFC 3986 path
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 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
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.
/*** @return*/var {return pathname && reqmethod === 'GET';};var apiProxy = ;
Options
-
option.pathRewrite: object/function, rewrite target's url path. Object-keys will be used as RegExp to match paths.
// rewrite pathpathRewrite: '^/old/api' : '/new/api'// remove pathpathRewrite: '^/remove/api' : ''// add base pathpathRewrite: '^/' : '/basepath/'// custom rewriting{ return path } -
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{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{// replace the default console log provider.return ;}// verbose replacement{var logger = new ;var myCustomProvider =log: loggerlogdebug: loggerdebuginfo: loggerinfowarn: loggerwarnerror: loggererror;return myCustomProvider;} -
option.onError: function, subscribe to http-proxy's
error
event for custom error handling.{ctxresponsestatus = 500;ctxresponsebody ='Something went wrong. And we are reporting a custom error message.';} -
option.onProxyRes: function, subscribe to http-proxy's
proxyRes
event.{proxyResheaders'x-added' = 'foobar'; // add new header to responsedelete proxyResheaders'x-removed'; // remove header from response} -
option.onProxyReq: function, subscribe to http-proxy's
proxyReq
event.{// add custom header to requestproxyReq;// or log the req} -
option.onUpgrade: function, called before upgrading a websocket connection.
onUpgrade: async {// add session middleware to the websocket connection// see option.appawait ;}; -
option.app: koa app, used to generate a koa ctx to be used in onUpgrade. If left blank, a object containing only
req
will be used as context -
option.headers: object, adds request headers. (Example:
{host:'www.example.org'}
) -
option.target: url string to be parsed with the url module
-
option.ws: true/false: if you want to proxy websockets
-
option.xfwd: true/false, adds x-forward headers
-
option.changeOrigin: true/false, Default: false - changes the origin of the host header to the target URL
-
option.proxyTimeout: timeout (in millis) when proxy receives no response from target
-
option.proxyName: Proxy name used for Via header
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.
;// proxy('/api', {target: 'http://www.example.org:8000'}); ;// proxy('/api/books/*/**.json', {target: 'http://www.example.org:8000'}); ;// proxy('/api', {target: 'http://www.example.org:8000'});
WebSocket
// verbose api; // shorthand; // shorter shorthand;
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.
var wsProxy = ; var app = ;app; var server = app;server; // <-- subscribe to http 'upgrade'
Tests
Run the test suite:
# install dependencies $ yarn # linting $ yarn lint$ yarn lint:fix # building (compile typescript to js) $ yarn build # unit tests $ yarn test # code coverage $ yarn cover
Changelog
License
The MIT License (MIT)
Copyright for portions of this project are held by Steven Chim, 2015-2019 as part of http-proxy-middleware. All other copyright for this project are held by Ontola BV, 2019.