def create_simple_compute_environment()

in lib/workshop.py [0:0]

• 77 lines of code
• 10 McCabe index (conditional complexity)

def create_simple_compute_environment(proj_name): 
    computeEnvironmentName = f"CE-{proj_name}"
    
    iam_client = boto3.client('iam')
    ec2_client = boto3.client('ec2')
    batch_client = boto3.client('batch')
    
    # use the default VPC for simplicity
    vpc_filter = [{'Name':'isDefault', 'Values':['true']}]
    default_vpc = ec2_client.describe_vpcs(Filters=vpc_filter)
    vpc_id = default_vpc['Vpcs'][0]['VpcId']

    subnet_filter = [{'Name':'vpc-id', 'Values':[vpc_id]}]
    subnets = ec2_client.describe_subnets(Filters=subnet_filter)
    subnet1_id = subnets['Subnets'][0]['SubnetId']
    subnet2_id = subnets['Subnets'][1]['SubnetId']


    batch_instance_role_name = f"batch_instance_role_{proj_name}"
    batch_instance_policies = ["arn:aws:iam::aws:policy/CloudWatchFullAccess", "arn:aws:iam::aws:policy/service-role/AmazonEC2ContainerServiceforEC2Role","arn:aws:iam::aws:policy/AmazonS3FullAccess"]
    create_service_role_with_policies(batch_instance_role_name, "ec2.amazonaws.com", batch_instance_policies)
    instance_profile_name =f"instance_profile_{proj_name}"
    try:
        iam_client.create_instance_profile(InstanceProfileName=instance_profile_name)
    except ClientError as e:
        if e.response['Error']['Code'] == 'EntityAlreadyExists':
            print("Instance profile already attached, ignore")
        else:
            raise e
    try:
        iam_client.add_role_to_instance_profile(InstanceProfileName=instance_profile_name, RoleName=batch_instance_role_name)
    except ClientError as e:
        print(e)
        
    instanceRole = iam_client.get_instance_profile(InstanceProfileName=f"instance_profile_{proj_name}")['InstanceProfile']['Arn']
    
    batch_service_role_name = f"batch_service_role_{proj_name}"
    batch_service_policies = ["arn:aws:iam::aws:policy/service-role/AWSBatchServiceRole", "arn:aws:iam::aws:policy/CloudWatchFullAccess"]
    serviceRole = create_service_role_with_policies(batch_service_role_name, "batch.amazonaws.com", batch_service_policies)

    batch_sg_name = f"batch_sg_{proj_name}"
    try:
        sg = ec2_client.create_security_group(
            Description='security group for Compute Environment',
            GroupName=batch_sg_name,
            VpcId=vpc_id
        )
        batch_sec_group_id=sg["GroupId"]
    except ClientError as e:
        if e.response['Error']['Code'] == 'InvalidGroup.Duplicate':
            print("SG already exists, ")
            resp = ec2_client.describe_security_groups(Filters=[dict(Name='group-name', Values=[batch_sg_name])])
            batch_sec_group_id = resp['SecurityGroups'][0]['GroupId']

    print('Batch security group id - ' + batch_sg_name)
    print(batch_sec_group_id)

    security_groups = [batch_sec_group_id]
    
    compute_resources = {
        'type': 'EC2',
        'allocationStrategy': 'BEST_FIT_PROGRESSIVE',
        'minvCpus': 4,
        'maxvCpus': 64,
        'desiredvCpus': 4,
        'instanceTypes': ['optimal'],
        'subnets': [subnet1_id,  subnet2_id],
        'securityGroupIds': security_groups,
        'instanceRole': instanceRole
    }
        
    response = batch_client.create_compute_environment(
        computeEnvironmentName=computeEnvironmentName,
        type='MANAGED',
        serviceRole=serviceRole,
        computeResources=compute_resources
    )

    while True:
        describe = batch_client.describe_compute_environments(computeEnvironments=[computeEnvironmentName])
        computeEnvironment = describe['computeEnvironments'][0]
        status = computeEnvironment['status']
        if status == 'VALID':
            print('\rSuccessfully created compute environment {}'.format(computeEnvironmentName))
            break
        elif status == 'INVALID':
            reason = computeEnvironment['statusReason']
            raise Exception('Failed to create compute environment: {}'.format(reason))
        print('\rCreating compute environment...')
        time.sleep(10)
            
    return response