In this pattern an Amazon EventBridge rule triggers an AWS Lambda function which deregisters an Amazon Machine Image (AMI), deletes the associated snapshot and moves them to the Recycle Bin for retention.

The AWS Lambda function automates the expiration of Amazon Machine Images (AMIs) by moving the AMIs and their associated snapshots to Recycle Bin. Recycle Bin is a feature of Amazon Elastic Compute Cloud (EC2) that allows you to retain AMIs that you have de-registered for a specified retention period, providing an opportunity to recover them if needed. To recover the deleted AMI, its associated snapshot should be recovered first. The Lambda function also adds corresponding tags to both, the AMI and the EBS snapshot, before moving them to Recycle Bin.