cd /opt
wget https://download.owncloud.com/server/stable/owncloud-complete-20210721.tar.bz2 --no-check-certificate
tar -xvf owncloud-complete-20210721.tar
sudo -u www-data php /var/www/html/owncloud/occ maintenance:mode --on
systemctl stop apache2
mv /var/www/html/owncloud /var/www/html/owncloud-current
mv /opt/owncloud /var/www/
chown -R www-data:www-data /var/www/html/owncloud
cp /var/www/html/owncloud-current/config/*config.php /var/www/html/owncloud/config/
cp -r /var/www/html/owncloud-current/apps-external /var/www/html/owncloud/
find -L /var/www/html/owncloud -type f -print0 | xargs -0 chmod 640
find -L /var/www/html/owncloud -type d -print0 | xargs -0 chmod 750
sudo -u www-data php /var/www/html/owncloud/occ upgrade
sudo -u www-data php /var/www/html/owncloud/occ maintenance:mode --off
systemctl start apache2