koa-http2-proxy2

forked from ontola/koa-http2-proxy. On its basis, the following problems are solved 👇

• ✅ 🐛: Fix http2 proxy ssl handshake error
• ✅ 🐛: Rewrote the websocket proxy section to solve the problem that the websocket proxy does not work
• ✅ 🚀: Context matching support for regular expressions

TL;DR

Proxy requests to http://www.example.org

1var Koa = require('koa');
2var proxy = require('koa-http2-proxy2');
3var app = new Koa();
4
5// response
6app.use(proxy({ target: 'http://www.example.org' }));
7
8app.listen(3000);
9
10// http://localhost:3000/foo/bar -> http://www.example.org/foo/bar

:bulb: Tip: Set the option changeOrigin to true for name-based virtual hosted sites.

Table of Contents

• Install
• Core concept
• Example
• Context matching
• Options
• Shorthand
  • app.use(path, proxy)
• WebSocket
  • External WebSocket upgrade
• Tests
• Changelog
• License

Install

1$ npm install --save-dev koa-http2-proxy2

Core concept

Proxy middleware configuration.

proxy([context,] config)

1var proxy = require('koa-http2-proxy2');
2
3var apiProxy = proxy('/api', { target: 'http://www.example.org' });
4//                   \____/   \_____________________________/
5//                     |                    |
6//                   context             options
7
8// '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-proxy2 configuration options)

proxy(uri [, config])

1// shorthand syntax for the example above:
2var apiProxy = proxy('http://www.example.org/api');

More about the shorthand configuration.

Example

1// include dependencies
2var Koa = require('koa');
3var proxy = require('koa-http2-proxy2');
4
5// proxy middleware options
6var options = {
7  target: 'http://www.example.org', // target host
8  ws: true, // proxy websockets
9  pathRewrite: {
10    '^/api/old-path': '/api/new-path', // rewrite path
11    '^/api/remove/path': '/path' // remove base path
12  },
13  router: {
14    // when request.headers.host == 'dev.localhost:3000',
15    // override target 'http://www.example.org' to 'http://localhost:8000'
16    'dev.localhost:3000': 'http://localhost:8000'
17  }
18};
19
20// create the proxy (without context)
21var exampleProxy = proxy(options);
22
23// mount `exampleProxy` in web server
24var app = new Koa();
25app.use(exampleProxy);
26app.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 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
  • proxy(/^\/([a-zA-Z0-9_/-]{1,})$/, {...}) - matches paths with regexp

• 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-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.

  1/**
  2 * @return {Boolean}
  3 */
  4var filter = function(pathname, req) {
  5  return pathname.match('^/api') && req.method === 'GET';
  6};
  7
  8var apiProxy = proxy(filter, { target: 'http://www.example.org' });

Options

• option.pathRewrite: object/function, rewrite target's url path. Object-keys will be used as RegExp to match paths.

  1// rewrite path
  2pathRewrite: {'^/old/api' : '/new/api'}
  3
  4// remove path
  5pathRewrite: {'^/remove/api' : ''}
  6
  7// add base path
  8pathRewrite: {'^/' : '/basepath/'}
  9
  10// custom rewriting
  11pathRewrite: function (path, req) { return path.replace('/api', '/base/api') }

• option.router: object/function, re-target option.target for specific requests.

  1// Use `host` and/or `path` to match requests. First match will be used.
  2// The order of the configuration matters.
  3router: {
  4    'integration.localhost:3000' : 'http://localhost:8001',  // host only
  5    'staging.localhost:3000'     : 'http://localhost:8002',  // host only
  6    'localhost:3000/api'         : 'http://localhost:8003',  // host + path
  7    '/rest'                      : 'http://localhost:8004'   // path only
  8}
  9
  10// Custom router function
  11router: function(req) {
  12    return 'http://localhost:8004';
  13}

• option.logLevel: string, ['debug', 'info', 'warn', 'error', 'silent']. Default: 'info'

• option.logProvider: function, modify or replace log provider. Default: console.

  1// simple replace
  2function logProvider(provider) {
  3  // replace the default console log provider.
  4  return require('winston');
  5}

  1// verbose replacement
  2function logProvider(provider) {
  3  var logger = new (require('winston')).Logger();
  4
  5  var myCustomProvider = {
  6    log: logger.log,
  7    debug: logger.debug,
  8    info: logger.info,
  9    warn: logger.warn,
  10    error: logger.error
  11  };
  12  return myCustomProvider;
  13}

• option.onError: function, subscribe to http-proxy's error event for custom error handling.

  1function onError(err, ctx) {
  2  ctx.response.status = 500;
  3  ctx.response.body =
  4    'Something went wrong. And we are reporting a custom error message.';
  5}

• option.onProxyRes: function, subscribe to http-proxy's proxyRes event.

  1function onProxyRes(proxyRes, ctx) {
  2  proxyRes.headers['x-added'] = 'foobar'; // add new header to response
  3  delete proxyRes.headers['x-removed']; // remove header from response
  4}

• option.onProxyReq: function, subscribe to http-proxy's proxyReq event.

  1function onProxyReq(proxyReq, ctx) {
  2  // add custom header to request
  3  proxyReq.setHeader('x-added', 'foobar');
  4  // or log the req
  5}

• option.onUpgrade: function, called before upgrading a websocket connection.

  1onUpgrade: async ctx => {
  2  // add session middleware to the websocket connection
  3  // see option.app
  4  await session(ctx, () => {});
  5};

• 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

• option.logs: true/false: Whether to enable log printing, default false

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.

1proxy('http://www.example.org:8000/api');
2// proxy('/api', {target: 'http://www.example.org:8000'});
3
4proxy('http://www.example.org:8000/api/books/*/**.json');
5// proxy('/api/books/*/**.json', {target: 'http://www.example.org:8000'});
6
7proxy('http://www.example.org:8000/api');
8// proxy('/api', {target: 'http://www.example.org:8000'});

WebSocket

1// verbose api
2proxy('/', { target: 'http://echo.websocket.org', ws: true });
3
4// shorthand
5proxy('http://echo.websocket.org', { ws: true });
6
7// shorter shorthand
8proxy('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.

1var wsProxy = proxy('ws://echo.websocket.org');
2
3var app = new Koa();
4app.use(wsProxy);
5
6var server = app.listen(3000);
7server.on('upgrade', wsProxy.upgrade); // <-- subscribe to http 'upgrade'

Tests

Run the test suite:

1# install dependencies
2$ yarn
3
4# linting
5$ yarn lint
6$ yarn lint:fix
7
8# building (compile typescript to js)
9$ yarn build
10
11# unit tests
12$ yarn test
13
14# code coverage
15$ yarn cover

Changelog

• View 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.