Recipes

Common usages of http-proxy-middleware.

Configuration example

Overview of http-proxy-middleware specific options.

http-proxy-middleware uses Nodejitsu's http-proxy to do the actual proxying. All of its options are exposed via http-proxy-middleware's configuration object.

const { createProxyMiddleware } = require('http-proxy-middleware');
const winston = require('winston');

/**
 * Context matching: decide which path(s) should be proxied. (wildcards supported)
 **/
const context = '/api';

/**
 * Proxy options
 */
const options = {
  // hostname to the target server
  target: 'http://localhost:3000',

  // set correct host headers for name-based virtual hosted sites
  changeOrigin: true,

  // enable websocket proxying
  ws: true,

  // additional request headers
  headers: {
    'x-powered-by': 'foobar',
  },

  // rewrite paths
  pathRewrite: {
    '^/api/old-path': '/api/new-path', // rewrite path
    '^/api/remove/path': '/path', // remove base path
  },

  // re-target based on the request's host header and/or path
  router: {
    // host[/path]                 :  <new target>
    // /path                       :  <new target>
    'integration.localhost:8000': 'http://localhost:8001', // host only
    'staging.localhost:8000': 'http://localhost:8002', // host only
    'localhost:8000/api': 'http://localhost:8003', // host + path
    '/rest': 'http://localhost:8004', // path only
  },

  // control logging
  logLevel: 'silent',

  // use a different lib for logging;
  // i.e., write logs to file or server
  logProvider: function (provider) {
    return winston;
  },

  // subscribe to http-proxy's error event
  onError: function onError(err, req, res) {
    res.writeHead(500, { 'Content-Type': 'text/plain' });
    res.end('Something went wrong.');
  },

  // subscribe to http-proxy's proxyRes event
  onProxyRes: function (proxyRes, req, res) {
    proxyRes.headers['x-added'] = 'foobar';
    delete proxyRes.headers['x-removed'];
  },

  // subscribe to http-proxy's proxyReq event
  onProxyReq: function (proxyReq, req, res) {
    // add custom header to request
    proxyReq.setHeader('x-powered-by', 'foobar');
  },

  /**
   * The following options are provided by Nodejitsu's http-proxy
   */

  // target
  // forward
  // agent
  // ssl
  // ws
  // xfwd
  // secure
  // toProxy
  // prependPath
  // ignorePath
  // localAddress
  // changeOrigin
  // auth
  // hostRewrite
  // autoRewrite
  // protocolRewrite
  // headers
};

/**
 * Create the proxy middleware, so it can be used in a server.
 */
const apiProxy = createProxyMiddleware(context, options);