Setup An IP Whitelist With Nginx

Basic Configuration

Define a common IP whitelist conf to be included

Edit /etc/nginx/conf.d/shared/ipwhitelist.conf

deny 192.168.1.1;       # deny the actual IP address
allow 127.0.0.1;        # allow the actual IP address to access such as 127.0.0.1 for localhost
allow 192.168.0.0/16;   # allow IP addresses in range
allow 172.16.0.0/16;
allow 10.10.0.0/16;
deny all;               # deny the rest of the world

Include the IP whitelist to your app's conf

Edit /etc/nginx/conf.d/your.conf

server{
   include /etc/nginx/conf.d/shared/ipwhitelist.conf
}

How to define IP in range

RFC1918 name	IP address range	Number of addresses	Largest CIDR block (subnet mask)	Host ID size	Mask bits	Classful description
24-bit block	10.0.0.0 – 10.255.255.255	16777216	10.0.0.0/8 (255.0.0.0)	24 bits	8 bits	single class A network
20-bit block	172.16.0.0 – 172.31.255.255	1048576	172.16.0.0/12 (255.240.0.0)	20 bits	12 bits	16 contiguous class B networks
16-bit block	192.168.0.0 – 192.168.255.255	65536	192.168.0.0/16 (255.255.0.0)	16 bits	16 bits	256 contiguous class C networks

See Wikipedia: https://en.wikipedia.org/wiki/Private_network#Private_IPv4_addresses