Generate a W3C valid rss feed for apt upgradeable packages. It first runs apt update then takes the output of apt list --upgradable.
To configure, just set url_origin which is your full url, eg https://www.myserver.com, save and run. You can also set the following optional variables...
url_pathname - the url subdirectory or file, defaults to index.html
file_path - path to your www directory and file, defaults to /var/www/html/index.html
feed_name - set the feed title, defaults to Apt Upgradeable Packages
Run regularly using cron.
Enjoy!