Set Cloudflare IP Addresses to nginx real_ip

cf_nginx.pl

#!/usr/bin/env perl

use strict;
use warnings;

use HTTP::Tiny;

my $prefix = 'cloudflare-origin';

die "ERR: requires one argument: output file path" unless scalar @ARGV == 1;

my @addrs = fetch('v4');
my @v6 = fetch('v6');
push(@addrs,@v6);

open(my $fh,">$ARGV[0]") or die "cannot open $ARGV[0]:$!";

# ngx_http_realip_module
foreach my $addr(@addrs){
        print $fh "set_real_ip_from $addr;\n";
}

print $fh "real_ip_header CF-Connecting-IP;\n";

close $fh;

sub fetch
{
        my $type = shift;

        my $client = HTTP::Tiny->new();
        my $res = $client->get("https://www.cloudflare.com/ips-$type");

        if(!$res->{success}){
                die "failure to fecth $type:$res->{reason}\n";
        }
        split(/\n/,$res->{content});
}