const fs = require('fs') const https = require('https') const path = require('path') const server = https.createServer({ key: fs.readFileSync(path.resolve(__dirname, 'tls.key.pem')), cert: fs.readFileSync(path.resolve(__dirname, 'tls.cert.pem')) }, (req, res) => { res.end(JSON.stringify({ protocol: req.socket.getProtocol() })) setTimeout(() => { server.close() }, 0) }) server.listen(0, () => { console.log(server.address().port) })