router.md

router

Allows you to route to a different target by using a table of a custom function.

• Custom router function
• Proxy Table
  • Example

Custom router function

Write your own router to dynamically route to a different target. The req object is provided to retrieve contextual data.

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

const customRouter = function (req) {
  return 'http://www.example.org'; // protocol + host
};

const options = {
  target: 'http://localhost:8000',
  router: customRouter,
};

const myProxy = createProxyMiddleware(options);

const app = express();
app.use(myProxy); // add the proxy to express

app.listen(3000);

Proxy Table

Use a Proxy Table to proxy requests to a different target based on:

• Host HTTP header.
• Request path
• Host HTTP header + path

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

const proxyTable = {
  '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
};

const options = {
  target: 'http://localhost:8000',
  router: proxyTable,
};

const myProxy = createProxyMiddleware(options);

const app = express();
app.use(myProxy); // add the proxy to express

app.listen(3000);

Example

In the example above; all requests will be proxied to http://localhost:8000.

When request's Host HTTP header and/or path match a configuration in the proxyTable, they will be send to matching target.

http://localhost:3000/lorum/ipsum             -> http://localhost:8000/lorum/ipsum
http://integration.localhost:3000/lorum/ipsum -> http://localhost:8001/lorum/ipsum
http://staging.localhost:3000/rest/foo/bar    -> http://localhost:8002/rest/foo/bar
http://localhost:3000/api/houses/123          -> http://localhost:8003/api/houses/123
http://localhost:3000/rest/books/123          -> http://localhost:8004/rest/books/123