Sync cloudflare IPs with NGINX

cloudflare_refresh_nginx.sh

# Based on https://support.cloudflare.com/hc/en-us/articles/200170706-How-do-I-restore-original-visitor-IP-with-Nginx-
# Save this file to /usr/bin/clodflare_refresh_nginx.sh
# Add the line "include /etc/nginx/global/cloudflare-ip.conf" to the server
# block of every nginx site you wish to expose the real IP for
# Add crontab (run a 03:05 every day): 5 3 * * * /usr/bin/clodflare_refresh_nginx.sh >/dev/null 2>&1                                                                                                                
NGINX_CONF=/etc/nginx/global/cloudflare-ip.conf
curl https://www.cloudflare.com/ips-v4 | perl -p -e 's/^(.*)$/set_real_ip_from \1;/g' >  $NGINX_CONF
curl https://www.cloudflare.com/ips-v6 | perl -p -e 's/^(.*)$/set_real_ip_from \1;/g' >> $NGINX_CONF
# use any of the following two
echo "real_ip_header CF-Connecting-IP;" >> $NGINX_CONF
# echo "real_ip_header X-Forwarded-For;" >> $NGINX_CONF

For CentOS 7, there are packages with those lists, which can be updated via yum update.