if(Seconds_Behind_Master > 900) RESTART_VSERVER();

check.sh

#!/bin/bash
set -euf -o pipefail
cd "$(dirname "$0")"

SERVER_HOST="fqdn.example.net"
SERVER_NAME="vXXXXXXXXXXXXXXXX"
SSH_HOST="user@server.internal-network.example.net"
SSH_ARGS="-i ./ssh.key -o ConnectTimeout=10 -o BatchMode=yes"
SSH_COMMAND="mysql --defaults-file=~/.slave.cnf -e 'show slave status \G' | grep -F Seconds_Behind_Master | cut -d : -f 2 | awk '{\$1=\$1};1'"

result=`ssh $SSH_ARGS "$SSH_HOST" -- "$SSH_COMMAND"`

if [[ "$result" != "NULL" && "$result" > 900 ]]
then
	echo "Seconds_Behind_Master: $result"
	echo ./reboot.php "$SERVER_NAME" "$SERVER_HOST"
fi

reboot.php

#!/usr/bin/php
<?php

if(php_sapi_name() !== 'cli' || $argc !== 3)
{
	dbg('Usage: %s <VSERVERNAME> <HOSTNAME>', basename(isset($argv[0]) ? $argv[0] : __file__));
	exit(1);
}

define('SCP_USERNAME', '1234567890');
define('SCP_PASSWORD', 'SECRETPASSWORD');
define('SERVER_NAME', $argv[1]);
define('SERVER_HOST', $argv[2]);

define('SHUTDOWN_WAIT',    5);
define('SHUTDOWN_RETRY',  20);
define('SHUTDOWN_LIMIT',  60);

define('START_WAIT',       1);
define('START_LIMIT',    120);

set_error_handler('exception_error_handler'); #error_reporting(-1);
$SCPWebServiceEndUser = new SCPWebServiceEndUser(SCP_USERNAME, SCP_PASSWORD);

$i = 0;
$t = null;
while(true)
{
	$state = $SCPWebServiceEndUser->getVServerState(SERVER_NAME);

	if($state === 'online')
	{
		if(!($i++ % SHUTDOWN_RETRY) || $t === null)
		{
			if($i > SHUTDOWN_LIMIT)
			{
				dbg(null);
				dbg('Time limit of %d seconds reached: Power off server %s!', SHUTDOWN_LIMIT * SHUTDOWN_WAIT, SERVER_NAME);

				$SCPWebServiceEndUser->vServerPoweroff(SERVER_NAME);

				dbg('Server %s powered off after %d seconds.', SERVER_NAME, time() - $t);
				break;
			}
			else if($t !== null)
			{
				dbg(null);
			}

			try
			{
				dbg('Sending ACPI shutdown signal to server %s!', SERVER_NAME);

				$SCPWebServiceEndUser->vServerACPIShutdown(SERVER_NAME);
				$t = time();

				dbg('Waiting for state update...', false);
			}
			catch(RuntimeException $e)
			{
				dbg('SOAP->vServerACPIShutdown(): %s', $e->getMessage());
			}
		}

		sleep(SHUTDOWN_WAIT);
		dbg('.', false);

		continue;
	}
	else if($state === 'offline')
	{
		if($t === null)
		{
			dbg('Server %s is already stopped.', SERVER_NAME);
		}
		else
		{
			dbg(null);
			dbg('Server %s successfully stopped after %d seconds.', SERVER_NAME, time() - $t);
		}

		break;
	}

	throw new RuntimeException(sprintf('Unsupported state: %s', $state));
}
unset($i, $t);

dbg('Starting server %s!', SERVER_NAME);
$SCPWebServiceEndUser->vServerStart(SERVER_NAME);
dbg('Waiting for online status...', false);

$i = 0;
$t = time();
while(true)
{
	$_ = $return = null;
	exec('ping -c 1 -n ' . escapeshellarg(SERVER_HOST) . ' 1>/dev/null', $_, $return);

	if(!$return)
	{
		dbg(null);
		dbg('Server %s successfully started after %d seconds.', SERVER_NAME, time() - $t);
		exit(0);
	}
	else if($i++ > START_LIMIT)
	{
		dbg(null);
		dbg('Time limit of %d seconds reached: Giving up!', SHUTDOWN_LIMIT * SHUTDOWN_WAIT);
		dbg(null);
		dbg('--------------------------------------');
		dbg(' !!! UNABLE TO CHECK SERVER STATE !!! ');
		dbg('--------------------------------------');
		exit(1);
	}
	else if($return !== 1)
	{
		dbg(null);
		dbg('-----------------------------------------------');
		dbg(' !!! UNSUPPORTED RESULT FROM PING RECEIVED !!! ');
		dbg('-----------------------------------------------');
		exit($return);
	}

	sleep(START_WAIT);
	dbg('.', false);
}

class SCPWebServiceEndUser
{
	const WSDL = 'https://www.servercontrolpanel.de/WSEndUser?wsdl';

	private $soap;
	private $username;
	private $password;

	public function __construct($username, $password)
	{
		$this->username = $username;
		$this->password = $password;

		$this->soap = new SOAPClient(self::WSDL);
	}

	public function getVServerState($name)
	{
		$result = $this->soap->getVServerState([
			'loginName'   => $this->username,
			'password'    => $this->password,
			'vserverName' => $name,
		]);

		return $result->return;
	}

	public function vServerPoweroff($name)
	{
		$result = $this->soap->vServerPoweroff([
			'loginName'   => $this->username,
			'password'    => $this->password,
			'vserverName' => $name,
		]);

		if($result->return === true)
		{
			return true;
		}

		$e = isset($result->return->message) ? new SCPWebServiceEndUserException($result->return->message) : null;
		throw new RuntimeException(sprintf('Could not power off vServer %s', $name), null, $e);
	}

	public function vServerACPIShutdown($name)
	{
		$result = $this->soap->vServerACPIShutdown([
			'loginName'   => $this->username,
			'password'    => $this->password,
			'vserverName' => $name,
		]);

		if($result->return === true)
		{
			return true;
		}

		$e = isset($result->return->message) ? new SCPWebServiceEndUserException($result->return->message) : null;
		throw new RuntimeException(sprintf('Could not send ACPI shutdown signal to vServer %s', $name), null, $e);
	}

	public function vServerStart($name)
	{
		$result = $this->soap->vServerStart([
			'loginName'   => $this->username,
			'password'    => $this->password,
			'vserverName' => $name,
		]);

		if($result->return === true)
		{
			return true;
		}

		$e = isset($result->return->message) ? new SCPWebServiceEndUserException($result->return->message) : null;
		throw new RuntimeException(sprintf('Could not start vServer %s', $name), null, $e);
	}
}

class SCPWebServiceEndUserException extends RuntimeException
{

}

function exception_error_handler($severity, $message, $file, $line)
{
	if(!(error_reporting() & $severity))
	{
		return;
	}

	throw new ErrorException($message, 0, $severity, $file, $line);
}

function dbg($message, $nl = null)
{
	$eol = PHP_EOL;
	$args = func_get_args();
	array_shift($args);

	if(is_bool($nl))
	{
		array_shift($args);

		if(!$nl)
		{
			$eol = '';
		}
	}

	fwrite(STDERR, vsprintf($message . $eol, $args));
}

?>