#!/usr/bin/env perl
# Copyright (c) 2007, Sofian Brabez <sbrabez@gmail.com>, <sbz@gcu.info>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer
#    in this position and unchanged.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. The name(s) of the author(s) may not be used to endorse or promote
#    products derived from this software without specific prior written
#    permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# $Id$ - configure the opendns nameserver from opendns.com
#
use strict;
use warnings;
use LWP::UserAgent;
use HTML::TreeBuilder;

my $path = {
  opendns => "https://www.opendns.com/start",
  resolvconf => '/etc/resolv.conf'
};

# webscraping at opendns.com
my $ua = new LWP::UserAgent("opendns/1.0");
my $response = $ua->get($path->{opendns});

die("Impossible to fetch opendns.com: " . $response->status_line) unless $response->is_success;

my $tree = new_from_content HTML::TreeBuilder($response->content);

# retrieve nameserver ip
my @list;
foreach my $element ($tree->find('h4')) {
  push(@list,$element->as_text);
}

open(my $fh, ">", "$path->{resolvconf}") or die("Can't open file $path->{resolvconf} $!");

# write nameserver ip
foreach my $ip (split(" ",($list[-2,-1]))) {
  print $fh "nameserver $ip$/";
}

close($fh);