This requires requests to be installed:
pip install requests
This is based on the Slack notification post-processor for AutoPkg/JSSImporter that Graham Pugh created: https://grahamrpugh.com/2017/12/22/slack-for-autopkg-jssimporter.html Which inspired Slacker https://github.com/notverypc/autopkg-recipes/blob/master/PostProcessors/Slacker.py Which contains all the good bits this Post Processor uses. This is just a port from Slack to Google Chat.
Change the following values to match your environment or pass them as environmental variables.
webhook_url
card_img
Example:
/usr/local/bin/autopkg run <your_recipe_list> --post="com.github.johnmikep.autopkg-recipes.postprocessors/Chatter" --key webhook_url="Your_Chat_webhook" --key card_img="your_preferred_img"