vhost

What is vhost?

The vhost npm package is used to create virtual hosts in a Node.js application. It allows you to define different hostnames for different parts of your application, enabling you to serve multiple domains from a single server.

What are vhost's main functionalities?

Basic Virtual Host Setup

This code demonstrates how to set up two virtual hosts using the vhost package. Requests to app1.example.com will be handled by app1, and requests to app2.example.com will be handled by app2.

const express = require('express');
const vhost = require('vhost');
const app = express();

const app1 = express();
app1.get('/', (req, res) => {
  res.send('Hello from app1.example.com!');
});

const app2 = express();
app2.get('/', (req, res) => {
  res.send('Hello from app2.example.com!');
});

app.use(vhost('app1.example.com', app1));
app.use(vhost('app2.example.com', app2));

app.listen(3000, () => {
  console.log('Server running on port 3000');
});

Wildcard Subdomains

This code demonstrates how to use wildcard subdomains with the vhost package. Any subdomain of example.com will be handled by subApp, and the subdomain name will be available in req.vhost.

const express = require('express');
const vhost = require('vhost');
const app = express();

const subApp = express();
subApp.get('/', (req, res) => {
  res.send(`Hello from ${req.vhost[0]}.example.com!`);
});

app.use(vhost('*.example.com', subApp));

app.listen(3000, () => {
  console.log('Server running on port 3000');
});

Other packages similar to vhost

http-proxy

The http-proxy package is a full-featured HTTP proxy for Node.js. It can be used to create a reverse proxy server, which can route requests to different backend servers based on the hostname or other criteria. Unlike vhost, which is specifically designed for virtual hosting within a single application, http-proxy is more general-purpose and can be used for a wider range of proxying tasks.

express-subdomain

The express-subdomain package allows you to define subdomain-specific routes in an Express application. It is similar to vhost in that it helps manage different parts of an application based on the hostname, but it is specifically focused on subdomains rather than full virtual hosts.

README

vhost

Install

$ npm install vhost

API

var vhost = require('vhost')

vhost(hostname, handle)

Create a new middleware function to hand off request to handle when the incoming host for the request matches hostname. The function is called as handle(req, res, next), like a standard middleware.

hostname can be a string or a RegExp object. When hostname is a string it can contain * to match 1 or more characters in that section of the hostname. When hostname is a RegExp, it will be forced to case-insensitive (since hostnames are) and will be forced to match based on the start and end of the hostname.

When host is matched and the request is sent down to a vhost handler, the req.vhost property will be populated with an object. This object will have numeric properties corresponding to each wildcard (or capture group if RegExp object provided) and the hostname that was matched.

// for match of "foo.bar.example.com:8080" against "*.*.example.com":
req.vhost.host === 'foo.bar.example.com:8080'
req.vhost.hostname === 'foo.bar.example.com'
req.vhost.length === 2
req.vhost[0] === 'foo'
req.vhost[1] === 'bar'

Examples

using with connect for static serving

var connect = require('connect')
var serveStatic = require('serve-static')
var vhost = require('vhost')

var mailapp = connect()

// add middlewares to mailapp for mail.example.com

// create app to serve static files on subdomain
var staticapp = connect()
staticapp.use(serveStatic('public'))

// create main app
var app = connect()

// add vhost routing to main app for mail
app.use(vhost('mail.example.com', mailapp))

// route static assets for "assets-*" subdomain to get
// around max host connections limit on browsers
app.use(vhost('assets-*.example.com', staticapp))

// add middlewares and main usage to app

app.listen(3000)

using with connect for user subdomains

var connect = require('connect')
var serveStatic = require('serve-static')
var vhost = require('vhost')

var mainapp = connect()

// add middlewares to mainapp for the main web site

// create app that will server user content from public/{username}/
var userapp = connect()

userapp.use(function(req, res, next){
  var username = req.vhost[0] // username is the "*"

  // pretend request was for /{username}/* for file serving
  req.originalUrl = req.url
  req.url = '/' + username + req.url

  next()
})
userapp.use(serveStatic('public'))

// create main app
var app = connect()

// add vhost routing for main app
app.use(vhost('userpages.local', mainapp))
app.use(vhost('www.userpages.local', mainapp))

// listen on all subdomains for user pages
app.use(vhost('*.userpages.local', userapp))

app.listen(3000)

using with any generic request handler

var connect = require('connect')
var http = require('http')
var vhost = require('vhost')

// create main app
var app = connect()

app.use(vhost('mail.example.com', function (req, res) {
  // handle req + res belonging to mail.example.com
  res.setHeader('Content-Type', 'text/plain')
  res.end('hello from mail!')
}))

// an external api server in any framework
var httpServer = http.createServer(function (req, res) {
  res.setHeader('Content-Type', 'text/plain')
  res.end('hello from the api!')
})

app.use(vhost('api.example.com', function (req, res) {
  // handle req + res belonging to api.example.com
  // pass the request to a standard Node.js HTTP server
  httpServer.emit('request', req, res)
}))

app.listen(3000)

License

MIT