Rotational Backup with PHP

A PHP script that backs up the web server's HTML directories on ALL-INKL.COM (or elsewhere 😉). The script can be run with a KAS cron job. It is very suitable for people who only have an ALL-INKL account and do not have a remote server with SSH and crontab.

Features

Folder structure is created automatically and automatically rotated when executing the KAS cron job.
The oldest backup will be deleted automatically.
A symlink to the most recent backup will be set.
The variable $NUM_BACKUPS defines the maximum number of backups. The default value is 7 (for one week with a daily KAS cron job).

Source Code

mysql-backup-allinkl.php

<?php
/**
 * Rotational PHP backup for ALL-INKL.COM
 * 
 * Features:
 * Creates the following folder structure and rotates it:
 * current -> /path/to/backup/daily.0
 * daily.0
 * daily.1
 * daily.2
 * daily.3
 * daily.4
 * daily.5
 * daily.6
 * daily.7
 * 
 * Usage:
 * If the script is to be executed automatically via KAS cron job, it must be accessible on the web.
 * Alternatively, it can be run manually via shell with the following command:
 * "php /path/to/script.php" (pitfall wrong PHP CLI version, then e.g. "/usr/bin/php81 /path/to/script.php" for PHP 8.1
 * See also: https:all-inkl.com/wichtig/anleitungen/kas/ssh/dateiverwaltung/aenderung-der-php-cli-version_527.html)
 * 
 * Restore folder(s):
 * rsync -avz --progress /www/htdocs/v0xxxxx/backup/public_websites/daily.0/folder /www/htdocs/v0xxxxx/public_websites/folder/
 * 
 * @author Helmut Kaczmarek <email@helmutkaczmarek.de>
 * @link https://wiki.helmutkaczmarek.de/code:php:backup:rotation
 * @todo You could also back up the directories to a remote server via SSH. However, at this point one would probably no longer be dependent on the "trimmed" KAS cron jobs from ALL-INKL.com. A bash script and crontab would of course be the first choice in this case.
 */
 
// Configuration variables
$SRC = "/www/htdocs/v0xxxxx/public_websites/";
$DEST = "/www/htdocs/v0xxxxx/backup/public_websites";
$NUM_BACKUPS = 7;
 
// Creating the directories
for ($i = 0; $i <= $NUM_BACKUPS; $i++) {
    mkdir($DEST . '/daily.' . $i, 0777, true);
}
 
// Delete the oldest backup
system('rm -rf ' . $DEST . '/daily.' . $NUM_BACKUPS);
 
// Rotation of backups
for ($i = $NUM_BACKUPS - 1; $i >= 0; $i--) {
    $prev = $i + 1;
    system('mv ' . $DEST . '/daily.' . $i . ' ' . $DEST . '/daily.' . $prev);
}
 
// Creating the new backup
system('rsync -arl --delete --stats --link-dest=' . $DEST . '/daily.1 ' . $SRC . ' ' . $DEST . '/daily.0');
 
// Symlink to the latest backup
unlink($DEST . '/current');
symlink($DEST . '/daily.0', $DEST . '/current');
 
?>