script for generating the snippet to include in the nginx configuration file for using the real ip address when logging access.

nginx-cloudflare-real-ip.sh

#!/usr/bin/env bash

for ip in $(curl -s https://www.cloudflare.com/ips-v4/); do
  echo "set_real_ip_from $ip;";
done
for ip in $(curl -s https://www.cloudflare.com/ips-v6/); do
  echo "set_real_ip_from $ip;";
done
echo "real_ip_header X-Forwarded-For;"
echo "real_ip_recursive on;"