DNS prefetch control header for Express

This middleware lets you set the X-DNS-Prefetch-Control to control browsers' DNS prefetching. Read more about it on MDN and on Chromium's docs.

Usage:

const dnsPrefetchControl = require('dns-prefetch-control')

// Set X-DNS-Prefetch-Control: off
app.use(dnsPrefetchControl())

// Set X-DNS-Prefetch-Control: off
app.use(dnsPrefetchControl({ allow: false }))

// Set X-DNS-Prefetch-Control: on
app.use(dnsPrefetchControl({ allow: true }))