gistfile1.php

#!/usr/bin/php
<?php

function latest_base_lsn() {
	exec('grep -H to_lsn /root/backup/base/*/xtrabackup_checkpoints', $options);
	if (!$options) {
		return null;
	}
	$options = array_map(function($opt) {
		preg_match('#/(\d+)/.+= (\d+)#', $opt, $matches);
		return array('date' => $matches[1], 'lsn' => $matches[2]);
	}, $options);
	usort($options, function($a, $b) {
		if ($b['lsn'] === $a['lsn']) {
			return $b['date'] - $a['date'];
		}
		return $b['lsn'] - $a['lsn'];
	});
	return $options[0];
}

function get_next_lsn($current, $date) {
	$dir = '/root/backup/increment/' . $current . '-' . $date;
	assert(file_exists($dir) && is_dir($dir));
	$file = $dir . '/xtrabackup_checkpoints';
	assert(file_exists($file));

	$settings = parse_ini_file($file);
	assert($settings['from_lsn'] == $current);

	return $settings['to_lsn'];
}

function available_increments() {
	$increments = array();

	$dir = dir('/root/backup/increment');

	while (false !== ($file = $dir->read())) {
		if (preg_match('#^(\d+)-(\d{14})$#', $file, $match)) {
			$date = $match[2];
			$lsn = $match[1];
			if (!isset($increments[$lsn]) || $increments[$lsn] < $date) {
				$next = get_next_lsn($lsn, $date);
				if ($next == $lsn) {
					// Skip empty incremental backups
					continue;
				}
				$increments[$lsn] = array('date' => $date, 'next' => $next);
			}
		}
	}
	$dir->close();

	ksort($increments, SORT_NUMERIC);

	return $increments;
}

function run_script($script) {
	$script = escapeshellarg($script);
	$command = "ssh root@localhost $script";
	$ret = system($command, $code);
	return array($ret, $code);
}

function prep_stream() {
	$script = <<<SCRIPT
mkdir /tmp/restore
if [ $? -ne 0 ]
then
	exit 1
fi
#service mysql stop
#rm -rf /var/lib/mysql/*
SCRIPT;
	list(, $code) = run_script($script);
	return !$code;
	$script = escapeshellarg($script);
	$command = "ssh root@localhost $script";
	$ret = system($command, $var);
	return !$var;
}

function cleanup() {
	$script = <<<SCRIPT
rm -rf /tmp/restore
SCRIPT;
	run_script($script);
}

function stream($path, $last, $base = false) {
	echo "Will stream $path";
	if ($base) echo " as base";
	if ($last) echo " and finish preparing\n";
	else echo " and do a partial prepare\n";
}

function restore() {
	echo "Restoring.\n";
}

$base = latest_base_lsn();

if (!$base) {
	echo 'No backups found.';
	exit(1);
}

$increments = available_increments();

$toStream = array();

$lsn = $base['lsn'];

while (isset($increments[$lsn])) {
	$inc = $increments[$lsn];
	$toStream[] = '/root/backup/increment/' . $lsn . '-' . $inc['date'];
	$lsn = $inc['next'];
}

if (!prep_stream()) {
	echo 'Unable to prepare for restore. ';
	echo "Is another restore happening?\n";
	exit(1);
}

// stream the base
stream('/root/backup/base/' . $base['date'], !$toStream, true);

// Stream everything else
while ($toStream) {
	$path = array_shift($toStream);
	stream($path, !$toStream);
}

// Do the restore
restore();

// Cleanup
cleanup();