A function for reopening a winston File logging transport post logrotation on a HUP signal. To send a HUP to your node service, use the postrotate configuration option from logrotate. `postrotate kill -HUP ‘cat /var/run/mynodeservice.pid‘`

winston-logrotate.js

function reopenTransportOnHupSignal(fileTransport) {
  process.on('SIGHUP', function() {
    var fullname = path.join(fileTransport.dirname, fileTransport._getFile(false));

    function reopen() {
      if (fileTransport._stream) {
        fileTransport._stream.end();
        fileTransport._stream.destroySoon();
      }

      var stream = fs.createWriteStream(fullname, fileTransport.options);
      stream.setMaxListeners(Infinity);

      fileTransport._size = 0;
      fileTransport._stream = stream;

      fileTransport.once('flush', function () {
        fileTransport.opening = false;
        fileTransport.emit('open', fullname);
      });

      fileTransport.flush();
    }

    fs.stat(fullname, function (err) {
      if (err && err.code == 'ENOENT') {
        return reopen();
      }
    });

  });
}

please, can you show who is fileTransport param?