Auto-Updater Script for Raspberry PI

I need a script to automatically update an application/folder on a Raspberry Pi. The script should be runnable as a cron job at night and check a server for the current software version by calling an URL like http://server/update/version The server will report the current version, a download URL for the update and a local folder where the update should be extracted. { "version": "5", "url": "http://server/update/[login to view URL]" "localFolder": "/home/application" } If the version number is larger than the one currently installed the script should download the archive from the URL provided into the local folder specified and extract it there. Then, the new software version number should be stored locally in a text file. Finally, the Raspberry Pi should be restarted. The downloaded file should be checked for integrity before extracting it.