Backing up an entire website with PHP

Question

I'm attempting to backup lots of website using this php code. The script basically goes through the whole public_html directory and adds all the folders and files recursively and zips them.

Here's what I've got so far:

if (!file_exists('/home/sites/'.$_SERVER['SERVER_NAME'].'/cbitsbackup/')) {
mkdir('/home/sites/'.$_SERVER['SERVER_NAME'].'/cbitsbackup/', 0777, true);
}
$filefront = '/home/sites/'.$_SERVER['SERVER_NAME'].'/cbitsbackup/backup-'.$_SERVER['SERVER_NAME'].'-day1';
$fileend = '.zip';
$time = time();

if(file_exists($filefront.$fileend)){
$file = $filefront.'-'.$time.$fileend;}
else{$file = $filefront.$fileend;};
zip_directory('/home/sites/'.$_SERVER['SERVER_NAME'].'/public_html',$file);


function zip_directory($source,$tempfile){
if(!extension_loaded('zip') || !file_exists($source)) return false;
$zip = new ZipArchive();
if(!$zip->open($tempfile,ZIPARCHIVE::CREATE)) return false;
$source = str_replace('\\','/',realpath($source));
if(is_dir($source) === true){
    $files = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($source), RecursiveIteratorIterator::SELF_FIRST);
    foreach($files as $file){
        $file = str_replace('\\', '/', realpath($file));
        if(is_dir($file) === true) $zip->addEmptyDir(str_replace($source . '/','', $file . '/'));
        else if(is_file($file) === true) $zip->addFromString(str_replace($source . '/', '', $file), file_get_contents($file));}}
elseif(is_file($source) === true) $zip->addFromString(basename($source), file_get_contents($source));
return $zip->close();}

The main problem at the moment is memory constraints (64M) because I'm running on a shared hosting platform. As far as I can see, the zip file is stored in memory until it is 'completed'. This is problem because I have a lot of websites which are much over this size. Is there anyway to write the zip file progressively to disk so my script isn't killed by the system? Could I even write this in Perl to get around this limit?

Answer 1

As you are using Linux, use this in a PHP file:

<?php system('zip -r backup *'); ?>

This will create a ZIP of all files/directories exists in the directory.

Answer 2

Depending on your intent, it might be better to skip PHP altogether and just run archiving programs on the command line (if your shared host allows SSH access), or through a cron job. Here are a few examples using programs commonly found on servers:

# Create a Gzipped TAR archive
tar -czf ~/backup.tar.gz /directory/to/archive

# Create a zip archive (`zip` isn't as common as tar in my experience)
zip -ur backup.zip /directory/to/archive

If you want dated backups of each site, that's still well within the scope of a shell command or script:

# This will iterate over all files and directories in the sites folder, so might
# need adjusting if there are other files in /home/sites/
for dir in /home/sites/*;
    do tar -czvf $dir/cbitsbackup/backup-$(date +%y-%m-%d).tar.gz -C $dir public_html;
done;

I'd consider the implications of archiving a site and downloading via a single HTTP request as it looks like you're trying to do: is this exposed/publicly accessible? If it isn't locked down, what is the impact of someone viewing any code in a site or sending many requests to the script (ie. denial of service)?