plugin.js

'use strict'
const fp = require('fastify-plugin')
const http = require('http')

function plugin (fastify, options, next) {
  const httpPort = options.httpPort ? options.httpPort : 80

  const server = http
    .createServer(function (req, res) {
      const {
        headers: { host },
        url
      } = req
      if (host) {
        const redirectUrl = `https://${host.split(':')[0]}${options.httpsPort ? `:${options.httpsPort}` : ''}${url}`
        res.writeHead(301, {
          Location: redirectUrl
        })
        res.end()
      }
    })
    .listen(httpPort)

  fastify.addHook('onClose', (_, done) => {
    server.close(function (err) {
      if (err) {
        throw err
      } else {
        done()
      }
    })
  })
  next()
}

module.exports = fp(plugin, {
  fastify: '>=2.0.0',
  name: 'fastify-https-redirect'
})