Nginx 取回 Cloudflare 代理後的瀏覽者真實 IP（搭配 http_realip_module 模組） Ref: https://virtubox.github.io/nginx-cloudflare-real-ip/

nginx_get_real_ip_from_cloudflare.sh

#!/bin/bash
if [ -z "$(command -v curl)" ]; then
    echo "####################################"
    echo "Installing CURL"
    echo "####################################"
    apt-get update
    apt-get install curl -y
fi

CURL_BIN=$(command -v curl)
CF_IPV4=$($CURL_BIN -sL https://www.cloudflare.com/ips-v4)
CF_IPV6=$($CURL_BIN -sL https://www.cloudflare.com/ips-v6)

echo '' > cloudflare.conf
echo "####################################"
echo "Adding Cloudflare IPv4"
echo "####################################"
for cf_ip4 in $CF_IPV4; do
    echo "set_real_ip_from $cf_ip4;" >> cloudflare.conf
done
echo "####################################"
echo "Adding Cloudflare IPv6"
echo "####################################"
for cf_ip6 in $CF_IPV6; do
    echo "set_real_ip_from $cf_ip6;" >> cloudflare.conf
done
echo 'real_ip_header CF-Connecting-IP;' >> cloudflare.conf