如何在node.js express中获取IP地址

我们如何从node.js获取IP地址我尝试了很多方法，但它不起作用并返回:: ffff：127.0.0.1，请给我一些建议

这是我的代码：

app.put('/update-user-info', function(req, res){
  // it's doesn't work and return ::ffff:127.0.0.1
  var ip = req.headers['x-forwarded-for'] || req.connection.remoteAddress ||  req.socket.remoteAddress || req.connection.socket.remoteAddress; 
});