#!/usr/bin/perl

#------------------------------------------------------------------------------
# check_http_content
# 	retrieve an http/s url and checks its content for a given expression
# 	if the expression is found exits with OK, otherwise exits with CRITICAL
#
# Copyright 2007, CAPSiDE SL	http://www.capside.com
# Licensed under GPLv2
#------------------------------------------------------------------------------
# 	Updated by Vahid Hedayati April 2013 - (improves nagios plugin result)
# 	Performance data for graphing added:
# 	1. time taken in milli seconds
# 	2. content size
#	Also added url and pattern match in alert output to make it easier to 
# 	identify actual issue
# 	This matches the check_http performance layout 
# 	and produces graphs in the same way
#------------------------------------------------------------------------------
#     This program is free software; you can redistribute it and/or modify
#     it under the terms of the GNU General Public License as published by
#     the Free Software Foundation; either version 2 of the License, or
#     (at your option) any later version.
# 
#     This program is distributed in the hope that it will be useful,
#     but WITHOUT ANY WARRANTY; without even the implied warranty of
#     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#     GNU General Public License for more details.
# 
#     You should have received a copy of the GNU General Public License
#     along with Opsview; if not, write to the Free Software
#     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#
# -----------------------------------------------------------------------------

use strict;
use Getopt::Std;
use LWP::UserAgent;
use Time::HiRes qw/ time sleep /;



my $plugin_name = 'check_http_content';
my $VERSION		= '0.01';

# getopt module config
$Getopt::Std::STANDARD_HELP_VERSION = 1;

# nagios exit codes
use constant EXIT_OK		=> 0;
use constant EXIT_WARNING	=> 1;
use constant EXIT_CRITICAL	=> 2;
use constant EXIT_UNKNOWN	=> 3;

my $start_run = time;
# parse cmd opts
my %opts;
getopts('vU:t:m:', \%opts);
$opts{t} = 60 unless (defined $opts{t});
if (not (defined $opts{U} and defined $opts{m})) {
	print "ERROR: INVALID USAGE\n";
	HELP_MESSAGE();
	exit EXIT_CRITICAL;
}

my $status = EXIT_OK;
# set trx timeout 
my $ua = LWP::UserAgent->new;
$ua->timeout($opts{t});

# retrieve url
 my $response = $ua->get($opts{U});
 my $expected_length;
 my $bytes_received = 0;
 my $end_run   = time;
 my $run_time = $end_run - $start_run;
if (not $response->is_success) {
	print "ERROR: CANNOT RETRIEVE URL: $opts{m} ", $response->status_line, "|time=".$run_time."s;;;0.000000 size=0B;;;0 \n";
	$status = EXIT_UNKNOWN;
} else {
	my $content = $response->content;
	if ($content =~ m/$opts{m}/gsm) {
               my($chunk, $resp) = $content;
               $bytes_received += length($chunk);
               unless (defined $expected_length) { $expected_length = $response->content_length || 0; }
               if ($expected_length) { printf STDERR "%d%% - ", 100 * $bytes_received / $expected_length; }
		print "CONTENT OK: EXPR $opts{m} FOUND on $opts{U}|time=".$run_time."s;;;0.000000 size=".$bytes_received."B;;;0 \n";
		$status = EXIT_OK;
	} else {
		my @output_lines = split(/\n/, $content);
		print "CONTENT ERROR: EXPR $opts{m} NOT FOUND on $opts{U} NOT FOUND (last: $output_lines[$#output_lines])\nfull output was:\n".$content."|time=".$run_time."s;;;0.000000 size=0B;;;0 \n";
		$status = EXIT_CRITICAL;
	}
}

exit $status;



sub HELP_MESSAGE 
{
	print <<EOHELP
	Retrieve an http/s URL and looks in its output for a given text. 
	Returns CRITICAL is not found, OK if found, UNKNOWN otherwise.
	
	--help      shows this message
	--version   shows version information

	-U          URL to retrieve (http or https)
	-m <text>   Text to match in the output of the URL
	-t          Timeout in seconds to wait for the URL to load. If the page fails to load, 
	            $plugin_name will exit with UNKNOWN state (default 60)

EOHELP
;
}


sub VERSION_MESSAGE 
{
	print <<EOVM
$plugin_name v. $VERSION
Copyright 2007, CAPSiDE SL - http://www.capside.com - Licensed under GPLv2

EOVM
;
}