ShellScript to output EBS Snapshots that are no longer referenced by AMIs

tda-stale-ami-snapshots.sh

#!/bin/bash

aws ec2 describe-snapshots --owner-ids $AWS_ACCOUNT_ID > snapshots.json
aws ec2 describe-images --owners $AWS_ACCOUNT_ID > images.json

cat snapshots.json \
  | jq '.Snapshots[] | select(.Description//""|startswith("Created by CreateImage"))' \
  > snapshot-to-ami.json

cat images.json \
  | jq '.Images[]|select(.RootDeviceType == "ebs")| {ImageId, SnapshotId:.BlockDeviceMappings[0].Ebs.SnapshotId}' \
  > ami-to-snapshot.json

cat snapshot-to-ami.json ami-to-snapshot.json \
  | jq -s 'group_by(.SnapshotId) | .[] | {SnapshotId:.[0].SnapshotId, ImageId: (.[].ImageId//null)} ' \
  > snapshot-ami-merge.json

cat snapshot-ami-merge.json \
  | jq -r 'select(.ImageId == null) | .SnapshotId'

Thanks, man! It's working well, does not touch any snapshots, used in existing AMI(s)