Fetches CloudFlare's official IPv4 and IPv6 addresses and formats them for use from NGinx's HttpRealipModule

CloudFlare's IPs for NGinx HttpRealipModule

# File name: cf_nginx_realip.rb

if ARGV.first == "--help"
  puts "Fetches CloudFlare's official IPv4 and IPv6 addresses and formats them for use from NGinx's HttpRealipModule"
  puts "Usage:\n\truby cf_nginx_realip.rb > cf_realip.conf\n\n"
  puts 'Then add "include cf_realip.conf" in a http|server|location block of your nginx config'
  exit
end
 
ips = []
ips << `curl -Ls https://www.cloudflare.com/ips-v4`
ips << `curl -Ls https://www.cloudflare.com/ips-v6`
puts ips.join("\n")
        .split("\n")
        .map { |ip_addr| "set_real_ip_from #{ip_addr};" }
        .push("real_ip_header CF-Connecting-IP;")
        .join("\n")