Node.js 实现同端口监听HTTP与HTTPS

const path = require('path');
const fs = require('fs');
const http = require('http');
const https = require('https');
const net = require('net');

/**
* Enable request handler being in HTTPS mode.
* @param handler {RequestListener}
* @param httpsConfig {{keyPath: string, certPath: string, [forceHttpsWhenEnabled]: boolean}}
* @return {Server & { https: Server, http: Server } }
*/
function enableHandlerHttps(handler, httpsConfig) {
  const options = {
    key: fs.readFileSync(path.resolve(httpsConfig.keyPath)),
    cert: fs.readFileSync(path.resolve(httpsConfig.certPath))
  };

  // If no need to forcibly redirect HTTP requests to same path HTTPS route.
  if (!httpsConfig.forceHttpsWhenEnabled) {
    // OK. Normal flow.
    return https.createServer(options, handler);
  }

  /**
   * Automatically redirect http request to https.
   * Only change the protocol.
   * @see https://stackoverflow.com/a/42019773
   */
  const net = require('net');
  const server = net.createServer(conn => {
    conn.once('data', buffer => {
      // Pause the socket.
      conn.pause();

      const firstByte = buffer[0];
      const httpReqFirstByteRange = [32, 127];
      const httpsReqFirstByte = 22;

      // Determine what proxy we need to use.
      let protocol;

      if (firstByte === httpsReqFirstByte) {
        protocol = 'https';
      } else if (
        httpReqFirstByteRange[0] < firstByte &&
        firstByte < httpReqFirstByteRange[1]
      ) {
        protocol = 'http';
      }

      const proxy = server[protocol];
      if (proxy) {
        // Push the buffer back onto the front of the data stream.
        conn.unshift(buffer);
        // Emit the socket to the HTTP(s) server.
        proxy.emit('connection', conn);
      }

      // As of NodeJS 10.x the socket must be
      // resumed asynchronously or the socket
      // connection hangs, potentially crashing
      // the process. Prior to NodeJS 10.x
      // the socket may be resumed synchronously.
      process.nextTick(() => {
        conn.resume();
      });
    });
  });

  // HTTP server proxy.
  server.http = http.createServer((req, res) => {
    // Force redirect.
    const host = req.headers['host'];
    // Use 301 - Moved Permanently.
    // To notify browsers that update the bookmarks and cache the redirection.
    res.writeHead(301, { Location: 'https://' + host + req.url });
    res.end();
  });

  // HTTPS server proxy.
  server.https = https.createServer(options, handler);

  return server;
}

const app = new Koa();

const server = enableHandlerHttps(app.callback(), {
  keyPath: '', // HTTPS cert key path.
  certPath: '', // HTTPS cert file path.
  forceHttpsWhenEnabled: true // Enable.
});

server.listen(3000, function () {
  // Server already started.
});