index.js

'use strict'
const express = require('express')
const LEX = require('letsencrypt-express').testing()

const DOMAIN = 'localhost'
const EMAIL = 'devnull@danpantry.me'
const lex = LEX.create({
  configDir: require('os').homedir() + '/letsencrypt/etc',
  approveRegistration(hostname, approve) {
    if (hostname === DOMAIN) {
      approve(null, { domains: [DOMAIN], email: EMAIL, agreeTos: true })
    }
  }
})

const app = express()
app.use(function (req, res) {
  // You can now use push here etc as 'res' is a Spdy response object.
  res.send('Hello, world!')
  res.end()
})

lex.onRequest = app
lex.listen([80], [443, 5001], function () {
  const protocol = 'requestCert' in this ? 'https' : 'http'
  console.log(`listening at ${protocol}://localhost:${this.address().port}`)
})