有没有办法确定试图连接到您的"HTTP服务器“的协议？

GET /index.html HTTP/1.1
Host: example.com
Upgrade-Insecure-Requests: 1

GET /chat HTTP/1.1
Host: example.com
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
Sec-WebSocket-Version: 13

GET /index.html HTTP/1.1
Host: example.com:80

GET /index.html HTTP/1.1
Host: example.com:443

const http = require('http');

const server = http.createServer((req, res) => {
  if (req.headers['upgrade-insecure-requests'] === '1') {
    res.writeHead(200, {'Content-Type': 'text/plain'});
    res.end('Protocol: HTTP (with upgrade request)');
  } else if (req.connection.encrypted) {
    res.writeHead(200, {'Content-Type': 'text/plain'});
    res.end('Protocol: HTTPS');
  } else {
    res.writeHead(200, {'Content-Type': 'text/plain'});
    res.end('Protocol: HTTP');
  }
});

server.listen(8080, () => {
  console.log('Server running at http://localhost:8080/');
});