def lambda_handler()

in cross-account-register-ztp/python/lambda/lambda_function.py [0:0]
84 lines of code
9 McCabe index (conditional complexity)

def lambda_handler(event, context):
    
    global client
    
    region = 'us-east-1' #default
    certificatePEM = ""
    attribute_1 = "undefined"

    body = json.loads(event['body'])
    
    if 'region' in body.keys():
        region=body['region']
    
    if 'certificate' in body.keys():
        certificatePEM = body['certificate']
        
    if thing_attribute_name in body.keys():
        attribute_1 = body[thing_attribute_name]

    client = boto3.client('iot', region_name=region)
    
    if not verify_certificate(certificatePEM):
        return {
            'statusCode': 400,
            'body': json.dumps('Failed to verify certificate.')
        }
        
    try:
        response = client.register_certificate_without_ca(
            certificatePem=certificatePEM,
            status='ACTIVE'
        )
    except Exception as e:
        return {
            'statusCode': 400,
            'body': json.dumps('Failed to register certificate: {}'.format(e))
        }
    certificateArn = response['certificateArn']
    certificateId = response['certificateId']
    
    try:
        response = client.create_thing(
            thingName = certificateId,
            attributePayload={
                'attributes': {
                    thing_attribute_name : attribute_1
                },
                'merge': True
            }
        )
    except Exception as e:
        print ('Failed to Create Thing')
        cleanup_resources(certificateArn, certificateId)
        return {
            'statusCode': 400,
            'body': json.dumps('Failed to create thing: {}'.format(e))
        }
    thingName = response['thingName']
    thingArn = response['thingArn']
    
    try:
        response = client.attach_principal_policy(
            policyName=managed_iot_policy,
            principal=certificateArn
        )
    except Exception as e:
        print ('Failed to attach policy to certificate')
        cleanup_resources(certificateArn, certificateId, thingName)
        return {
            'statusCode': 400,
            'body': json.dumps('Failed to attach policy to cert: {}'.format(e))
        }
        
    try:
        response = client.attach_thing_principal(
            thingName=thingName,
            principal=certificateArn
        )
    except Exception as e:
        print ('Failed to attach certificate to Thing')
        cleanup_resources(certificateArn, certificateId, thingName)
        return {
            'statusCode': 400,
            'body': json.dumps('Failed to attach cert to thing: {}'.format(e))
        }
    
    response = client.describe_endpoint(
        endpointType='iot:Data-ATS'
    )
    endpointAddress = {
        'endpointAddress': response['endpointAddress']
    }
    
    print ('Successfully created thing, registered certificate.')
    return {
        'statusCode': 200,
        'body': json.dumps(endpointAddress)
    }