如何在 Nodejs 中查找所有用户的 geoip 位置

I have a requirement where i have to find the geoip location of the users. I have used the code where i store the address of the user in database and then display the geoip location of that user.Now suppose the users changed his location to some other place.If the user now logs in from that region or country, how should i display the geoip of that user. The code that i use is:

geo.geocoder(geo.google, address, sensor,function(formattedAddress, latitude, longitude) {
             console.log("Formatted Address: " + formattedAddress);
             console.log("Latitude: " + latitude);
             console.log("Longitude: " + longitude);
             user.latitude = latitude;
             user.longitude = longitude;
             user.save(function(err) {
               if(err)
                 return userUpdateFailed();
               req.flash('info', 'Succesfully Upadated Changes');
               res.redirect('/userinfo');
             });
          });

有没有其他方法可以找到用户的确切位置.请帮助