A quite nasty first shot which does the trick. Feel free to improve it !
This piece of PHP code can be used to backup a website (root dir + db) on your google drive It has several prerequisites wich can also be found inside of the config sample
Don't forget to create your GOOGLE API KEY, to place the credentials.json in the same dir as this script and to run composer update to get all dependancies NOTICE: On the first call, you will have a command line prompt to enter a code
THIS VERSION OF THE SCRIPT DOES NOT CREATE A FOLDER ON GDRIVE. If you want to put your backup in a specific folder, use FOLDER_ID attribute. If not set, backups will be put at the root of your GDrive
TO ADD TO CRONTAB Example: to run the job every monday at 19:30
30 19 * * 1 php <dir of install>/run.php