#!/usr/local/bin/php -n
<?
/*

This script is designed to inform about the status of the 
server it runs on and send an warning by email, if any 
problems are detected. 

Only PHP and a mail server are required - no database like MySQL

The author is Michael Mayer (michael@liquidbytes.net)

(c) 2003 Liquid Bytes Technologies, Germany 

*/

// IMPORT COMMAND LINE ARGUMENTS

$argc = $_SERVER['argc'];
$argv = $_SERVER['argv'];

$config['mail_to']			= 'your@address';
$config['mail_from']			= 'Watchdog <from@address>';
$config['hostname']			= 'full.server.name';
$config['init_script_ok'] 		= 'done';
$config['sshd_init']      		= 'sshd';
$config['httpd_init']     		= '/etc/httpd/bin/apachectl';
$config['mysqld_init']    		= 'mysql';
$config['mysqld_user']    		= 'root';
$config['mysqld_pass']    		= '';
$config['load_limit']			= 4;
$config['filesystem_warning_limit']	= 10;
$config['filesystem_error_limit']	= 5; // must be less than filesystem_warning_limit!

// INIT ERROR VARIABLE

$error = 0;

// TEST MySQL

if(function_exists("mysql_connect")) {
	if(mysql_connect('localhost',$config['mysqld_user'],$config['mysqld_pass']) === FALSE) {
		$mysql_status = 'ERROR (could not connect)';
		$error = 1;

		// here, we want to try to restart the mysql process [TODO]
		/*
		$result = '';
		system('/etc/init.d/'.$config['mysqld_init'].' stop &');
		sleep(5);
		system('killall -9 mysqld');
		system('killall -9 save_mysqld');
		system('/etc/init.d/'.$config['mysqld_init'].' start && /root/scripts/watchdog.php &');
		exit;
		*/
		}
	else {
		$mysql_status = 'Ok';
		}
	}
else {
	$mysql_status = 'ERROR (no MySQL support in PHP)';
	$error = 1;
	}

// TEST HTTPD WEBSERVER

if(fsockopen('localhost',80,$errno,$errstr,30) === FALSE) {
	$httpd_status = 'ERROR ('.$errstr.')';
	$error = 1;
	system($config['httpd_init'].' stop');
	system($config['httpd_init'].' start');
	if(fsockopen('localhost',80,$errno,$errstr,30) !== FALSE) {
		$httpd_status .= ' - RESTART SUCCESSFUL - NO ACTION REQUIRED';
		}
	}
else {
	$httpd_status = 'Ok';
	}

// TEST SSHD

if(fsockopen('localhost',22,$errno,$errstr,30) === FALSE) {
	$sshd_status = 'ERROR ('.$errstr.')';
	$error = 1;
	system('/etc/init.d/'.$config['sshd_init'].' stop');
	system('/etc/init.d/'.$config['sshd_init'].' start');
	if(fsockopen('localhost',22,$errno,$errstr,30) !== FALSE) {
		$sshd_status .= ' - RESTART SUCCESSFUL - NO ACTION REQUIRED';
		}
	}
else {
	$sshd_status = 'Ok';
	}

// TEST FREE BOOT SPACE

$boot_free_space = round(100 * (disk_free_space('/boot') / disk_total_space('/boot')));

if($boot_free_space <= 10) {
	$boot_status = "WARNING - ONLY $boot_free_space % FREE ON BOOT DEVICE";
	$error = 1;
	}
else {
	$boot_status = "Ok - $boot_free_space % free";
	}

// TEST FREE FILESYSTEM SPACE

$free_space = round(100 * (disk_free_space('/') / disk_total_space('/')));

if($free_space == 0) {
	$filesystem_status = "ERROR - NO SPACE LEFT ON DEVICE";
	$error = 1;
	}
elseif($free_space <= $config['filesystem_error_limit']) {
	$filesystem_status = "WARNING - ONLY $free_space % FREE ON DEVICE";
	$error = 1;
	}
elseif($free_space <= $config['filesystem_warning_limit']) {
	$filesystem_status = "WARNING - ONLY $free_space % FREE ON DEVICE";
	}
else {
	$filesystem_status = "Ok - $free_space % free";
	}

// TEST SERVER LOAD

$fp = fopen('/proc/loadavg', 'r');
$loadavg = fgetcsv($fp, 1000, ' ');
fclose($fp);

if(is_numeric($loadavg[1])) {
	$load = $loadavg[1];
	}
else {
	$load = -1;
	}

if($load >= $config['load_limit']) {
	$load_status = "WARNING - SERVER LOAD IS $load";
	$error = 1;
	}
else {
	$load_status = "Ok - $load (5min avg)";
	}

// TEST SYSTEM MEMORY

$mem_file = file('/proc/meminfo');
while(list($key, $value) = each($mem_file)) {
	if(strpos($value, ':') !== FALSE) {
		$line_tok = explode(':', $value);
		$value_tok = explode(' ', trim($line_tok[1]));
		if(is_numeric($value_tok[0])) {
			$mem_array[trim($line_tok[0])] = trim($value_tok[0]);
			}
		}	
	}

// test array size, just to be sure, that there will be no errors...
if(count($mem_array) > 10) {

	$swap_free_space = round(100 * ($mem_array['SwapFree'] / $mem_array['SwapTotal']));

	if($swap_free_space >= 20) {
		$swap_status = "Ok - $swap_free_space % swap space free";
		}
	elseif($swap_free_space > 0) {
		$swap_status = "WARNING - ONLY $swap_free_space % SWAP SPACE FREE";
		$error = 1;
		}
	elseif($swap_free_space == 0) {
		$swap_status = "ERROR - NO FREE SWAP SPACE";
		$error = 1;
		}


	}
else {
	$swap_status = 'ERROR - PROBLEMS WHILE READING MEMORY INFORMATION';
	$error = 1;
	}

// COMPOSE MAIL

$body = "SERVICES\n".
	"MySQL : $mysql_status\n".
	"HTTPD : $httpd_status\n".
	"SSHD  : $sshd_status\n\n".
	"FILESYSTEM STATUS\nTotal space: ".round(disk_total_space('/') / 1048576)." MB\n".
	"Free space : ".round(disk_free_space('/') / 1048576)." MB\n".
	"Status     : ".$filesystem_status."\n".
	"Boot Device: ".$boot_status."\n\n".
	"OPERATING SYSTEM\n".
	"Server Load : $load_status\n".
	"Total Memory: ".round($mem_array['MemTotal'] / 1024)." MB\n".
	"Free Memory : ".round($mem_array['MemFree'] / 1024)." MB\n".
	"Swap Total  : ".round($mem_array['SwapTotal'] / 1024)." MB\n".
	"Swap Free   : ".round($mem_array['SwapFree'] / 1024)." MB\n".
	"Swap Status : $swap_status\n\n".
	"Report generated by ".$config['hostname']." (".date('D M j G:i:s T Y').")";

// SEND MAIL

if($error == 0 && $argc > 0 && $argv[1] == 'send_mail') {
	$subject = 'Server Status Report ('.$config['hostname'].')';
	$body .= "\nNote: This mail was sent though there is no error on this system. There is no action required.";
	mail($config['mail_to'], $subject, $body, 'From: '.$config['mail_from']);
	}
elseif($error == 1) {
	$subject = 'CRITICAL SYSTEM FAILURE DETECTED ('.$config['hostname'].')';
	mail($config['mail_to'], $subject, $body, 'From: '.$config['mail_from']);
	}


?>