def handler()

in functions/source/CleanupACMDNSValidation/handler.py [0:0]
43 lines of code
7 McCabe index (conditional complexity)

def handler(event, context):
    print('Received event: %s' % json.dumps(event))
    status = cfnresponse.SUCCESS
    physical_resource_id = None
    data = {}
    reason = None

    try:

        if event['RequestType'] == 'Create':
            token = ''.join(ch for ch in str(event['StackId'] + event['LogicalResourceId']) if ch.isalnum())
            token = token[len(token) - 32:]
            # Generated Physical ID doesn't do anything on create
            physical_resource_id = token
        elif event['RequestType'] == 'Update':
            # doesn't do anything on create
            physical_resource_id = event['PhysicalResourceId']
        elif event['RequestType'] == 'Delete':
            acm_arn = event["ResourceProperties"]["ACMArn"]
            hosted_zone_id = event['ResourceProperties']['HostedZoneId']
            physical_resource_id = event['PhysicalResourceId']

            changes = []
            for d in acm_client.describe_certificate(CertificateArn=acm_arn)['Certificate']['DomainValidationOptions']:
                record_name = d['ResourceRecord']['Name']
                record_type = d['ResourceRecord']['Type']

                # Retreiving information about the record (we need TTL in particular)
                response = r53_client.list_resource_record_sets(
                    HostedZoneId=hosted_zone_id,
                    StartRecordName=record_name,
                    StartRecordType=record_type
                )
                
                record = next(filter(lambda x: x['Name'] == record_name, response['ResourceRecordSets']))

                changes.append({
                    'Action': 'DELETE', 
                    'ResourceRecordSet': {
                        'Name': record_name, 
                        'Type': record_type, 
                        'TTL': record['TTL'], 
                        'ResourceRecords': record['ResourceRecords']
                    }
                })

            r53_client.change_resource_record_sets(HostedZoneId=hosted_zone_id, ChangeBatch={'Changes': changes})

    except Exception as e:
        logging.error('Exception: %s' % e, exc_info=True)
        reason = str(e)
        status = cfnresponse.FAILED
    finally:
        cfnresponse.send(event, context, status, data, physical_resource_id, reason)