Enable Real IP in Nginx behind Cloudflare

enable_real_ip.sh

#!/bin/bash

# Check if nginx is installed
echo "Check if nginx is installed"
if [[ $(dpkg-query -W -f='${Status}' nginx 2>/dev/null | grep -c "ok installed") -eq 0 ]]; then
    echo "nginx is not installed"
    exit 1
fi

echo "Check if http_realip_module and realip_module are active in nginx"
# check if http_realip_module and realip_module are active in nginx
if [[ $(nginx -V 2>&1 | grep -o 'http_realip_module') != "http_realip_module" ]]; then
    echo "http_realip_module is not enabled"
    exit 1
fi

if [[ $(nginx -V 2>&1 | grep -o 'realip_module') != "realip_module" ]]; then
    echo "realip_module is not enabled"
    exit 1
fi

echo "Append configuration to nginx.conf"

sed -i -e '/set_real_ip_from/d' -e '/real_ip_header/d' /etc/nginx/nginx.conf
sed -i '/http {/a\    set_real_ip_from 173.245.48.0/20;' /etc/nginx/nginx.conf
sed -i '/http {/a\    set_real_ip_from 103.21.244.0/22;' /etc/nginx/nginx.conf
sed -i '/http {/a\    set_real_ip_from 103.22.200.0/22;' /etc/nginx/nginx.conf
sed -i '/http {/a\    set_real_ip_from 103.31.4.0/22;' /etc/nginx/nginx.conf
sed -i '/http {/a\    set_real_ip_from 141.101.64.0/18;' /etc/nginx/nginx.conf
sed -i '/http {/a\    set_real_ip_from 108.162.192.0/18;' /etc/nginx/nginx.conf
sed -i '/http {/a\    set_real_ip_from 190.93.240.0/20;' /etc/nginx/nginx.conf
sed -i '/http {/a\    set_real_ip_from 188.114.96.0/20;' /etc/nginx/nginx.conf
sed -i '/http {/a\    set_real_ip_from 197.234.240.0/22;' /etc/nginx/nginx.conf
sed -i '/http {/a\    set_real_ip_from 198.41.128.0/17;' /etc/nginx/nginx.conf
sed -i '/http {/a\    set_real_ip_from 162.158.0.0/15;' /etc/nginx/nginx.conf
sed -i '/http {/a\    set_real_ip_from 104.16.0.0/13;' /etc/nginx/nginx.conf
sed -i '/http {/a\    set_real_ip_from 104.24.0.0/14;' /etc/nginx/nginx.conf
sed -i '/http {/a\    set_real_ip_from 172.64.0.0/13;' /etc/nginx/nginx.conf
sed -i '/http {/a\    set_real_ip_from 131.0.72.0/22;' /etc/nginx/nginx.conf
sed -i '/http {/a\    real_ip_header CF-Connecting-IP;' /etc/nginx/nginx.conf

# test if nginx configuration is ok
if [[ $(nginx -t 2>&1 | grep -o 'successful') != "successful" ]]; then
    echo "nginx configuration is not ok"
    exit 1
fi

# restart nginx
echo "Restart nginx"
systemctl restart nginx

echo "Done"