text: const http = require('http')
  
  http
    .createServer(function (req, res) {
      console.log(req.headers)
      res.writeHead(200, { 'Content-Type': 'text/plain' })
      res.end(
        [
          'Hello World',
          process.env.FOO,
          process.env.HTTP_PROXY,
          'x-forwarded-host: ' + req.headers['x-forwarded-host'],
          'host: ' + req.headers.host,
        ].join(' ')
      )
    })
    .listen(process.env.PORT, '127.0.0.1')
  
  console.log('Server listening on port', process.env.PORT)
  