Lambda handler

lambda.py

def lambda_handler(event, context):
  amis_in_use = []
  total_amis_deleted = 0
  total_snapshots_deleted = 0
  try:
    regions = event['regions']
    max_ami_age_to_prevent_deletion = event['max_ami_age_to_prevent_deletion']

    filters = makeAmiFilters(event['ami_tags'])

    for region in regions:
      amis_in_use = list(set(imagesInASGs(region) + imagesUsedInEC2s(region)))
      ec2 = boto3.client('ec2', region_name = region)
      amis = ec2.describe_images(
        Owners = ['self'],
        Filters = filters
      ).get('Images')
      for ami in amis:
        now = datetime.now()
        ami_id = ami['ImageId']
        img_creation_datetime = datetime.strptime(ami['CreationDate'], '%Y-%m-%dT%H:%M:%S.%fZ')
        days_since_creation = (now - img_creation_datetime).days

        if ami_id not in amis_in_use and days_since_creation > max_ami_age_to_prevent_deletion:
          ec2.deregister_image(ImageId = ami_id)
          total_amis_deleted += 1

          for ebs in ami['BlockDeviceMappings']:
            if 'Ebs' in ebs:
              snapshot_id = ebs['Ebs']['SnapshotId']              
              ec2.delete_snapshot(SnapshotId=snapshot_id)
              total_snapshots_deleted += 1

    print(f"Deleted {total_amis_deleted} AMIs and {total_snapshots_deleted} EBS snapshots")

  except Exception as e:
    send_alert(f"AMI cleaner failure", e)