I need to make my nginx so that it will only allow certain ips to use it .

My question is there anyway to create and external database that ngix will check to see if the ip is allowed to view the site as the way it will work is that all users will have a registerd account on my website and they will be able to each have one ip that they will be able to use with nginx and if there ip address changes they will be able to update there ip on my website .If a users ip is not on the white list the webpage that loads should be a my website to give the user the chance to update there ip to the whitelist

All the allowed Ips Will be stored in some sort off database but unsure on how i would implement this with nginx .

If anyone could tell me the best database to use and how to get nginx to read from that database that would be a massive help as i can then build the web system around that

Thanks