Installation

npm

npm i -S koa-verify-hostname

yarn

yarn add koa-verify-hostname

Usage

const app = new Koa()

const verifyHostname = require('koa-verify-hostname')
app.use(verifyHostname('localhost'))
// access 'localhost' -> next middleware
// access '127.0.0.1' -> response status 403
// access '[::1]' -> response status 403

You can also pass into a RegExp, or an Array contains string and RegExp .

app.use(verifyHostname(/[a-z]+\.example\.com/i))
// access 'example.com' -> response status 403
// access 'foo.example.com' -> next middleware
// access 'bar.example.com' -> next middleware
// access 'barexample.com' -> response status 403

app.use(verifyHostname(['example.com', /[a-z]+\.example\.com/i]))
// access 'example.com' -> next middleware
// access 'foo.example.com' -> next middleware
// access 'bar.example.com' -> next middleware
// access 'barexample.com' -> response status 403

If you want to customize the response, you can pass a function into verifyHostname() as the second argument.

app.use(verifyHostname('example.com', async (ctx, next, isValid) => {
    // isValid will be true when accessed by valid hostname
  if(!isValid) {
    ctx.status = 403
    ctx.body = 'Invalid Hostname.'
  }
  else
    await next()
})))