new_contents: import boto3
  import re
  import datetime
  
  ec = boto3.client('ec2')
  iam = boto3.client('iam')
  
  """
  This function looks at *all* snapshots that have a "DeleteOn" tag containing
  the current day formatted as YYYY-MM-DD. This function should be run at least
  daily.
  """
  
  def lambda_handler(event, context):
      account_ids = list()
      try:
          """
          You can replace this try/except by filling in `account_ids` yourself.
          Get your account ID with:
          > import boto3
          > iam = boto3.client('iam')
          > print iam.get_user()['User']['Arn'].split(':')[4]
          """
          iam.get_user()
      except Exception as e:
          # use the exception message to get the account ID the function executes under
          account_ids.append(re.search(r'(arn:aws:sts::)([0-9]+)', str(e)).groups()[1])
  
  
      delete_on = datetime.date.today().strftime('%Y-%m-%d')
      filters = [
          {'Name': 'tag-key', 'Values': ['DeleteOn']},
          {'Name': 'tag-value', 'Values': [delete_on]},
      ]
      snapshot_response = ec.describe_snapshots(OwnerIds=account_ids, Filters=filters)
  
  
      for snap in snapshot_response['Snapshots']:
          print "Deleting snapshot %s" % snap['SnapshotId']
          ec.delete_snapshot(SnapshotId=snap['SnapshotId'])
  
subject: Create lambda-ebs-backup-cleanup.py