hode-http2-server-push.js

const server = http2.createSecureServer(options);
const commonCSS = fs.readFileSync('common.css');
server.on('stream', (stream, headers) => {
  console.log(`${headers[':method']} ${headers[':path']}`);
  const parsedUrl = url.parse(headers[':path']);

  let pathname = `.${parsedUrl.pathname}`;
  const ext = path.parse(pathname).ext;
  if (headers[':path'] === '/index.html') {
    stream.pushStream({ ':path': 'common.css' },
      (pushStream) => {
        pushStream.respond({
          ':status': 200,
          'content-type': 'text/css'
        });
        pushStream.end(commonCSS, () => {});
      });
    const indexPath = path.join(__dirname, pathname);
    const readStream = fs.createReadStream(indexPath);
    readStream.on('open', function () {
      stream.respond({
        'content-type': mimeType[ext] || 'text/plain',
        ':status': 200
      });
      readStream.pipe(stream);
    });
  } else {
    // остальная статика
  }
});

server.listen(8800);