Script that takes the current IP address of a server and updates its record with Google Domains

google-dns-updater.pl

#!/usr/bin/env perl

use strict;
use warnings;
use HTTP::Request;
use LWP::UserAgent;
use Regexp::Common qw /net/;
use JSON;
use Socket;

my $username = '<FILLME>';
my $password = '<FILLME>';
my $hostname = '<FILLME>';

my $ua = LWP::UserAgent->new;

# Get the current external IP according to checkip.dyndns.org
my $ipreq = HTTP::Request->new(GET => 'http://checkip.dyndns.org');
my $ipres = $ua->request($ipreq);
my $ip = '';
if ($ipres->is_success) {
  if ($ipres->content =~ /$RE{net}{IPv4}{-keep}/) {
    $ip = $1;
  }
}
else {
  die ($ipres->content);
}

my $address = inet_ntoa(inet_aton($hostname));

# Print the time so we have a point of reference
print time() . "\n";

unless ($address =~ $ip) {
  my $api = "https://domains.google.com/nic/update?hostname=${hostname}&myip=$ip";
  my $req = HTTP::Request->new(GET => $api);
  $req->authorization_basic($username, $password);

  my $res = $ua->request($req);

  if ($res->is_success) {
    print $res->content . "\n";
  }
  else {
    die ($res->content);
  }
}
else {
  print "No update needed\n";
}