step-functions: reference path in nested object doesn't work

[tonyhoo]

• I'm submitting a ...

  • [✔️] :rocket: feature request

• What is the current behavior? The $.syntax for nested parameter won't work. For example new sfn_tasks.SagemakerTransformTask(this, {transformJobName: "$.jobName"}); will result in failure due to name regex validation error during execution. The reason is that when converting to cloudformation, it won't suffix parameter name with .$ which is required for nested field per ASL definition

• What is the expected behavior (or behavior of feature suggested)? Automatically detect such use case and convert to cfn correctly

• What is the motivation / use case for changing the behavior or adding this feature? There are lots of use cases require dynamic loading parameters from workflow shared context per execution. For example, SageMaker enforces the transformJobName to be unique everytime, so there is a strong need to create new/dynamic jobName per execution instead of using hard coded value

• Please tell us about your environment:

  • CDK CLI Version: 0.35.0
  • Module Version: 0.35.0
  • OS: [all]
  • Language: [TypeScript ]

[NGL321]

Hi @tonyhoo!

Thank you for contributing! I just wanted to let you know, we are working hard to stabilize the CDK APIs and tuning them to meet our consistency guidelines. While we work on getting the APIs aligned with our guidelines, we are pausing work on most community feature-requests. We expect to get back to work on community feature-requests within a few weeks.

[wqzoww]

Hi @tonyhoo Thank you for your feedback. For information, we do not detect reference path given in a literal string today. To declare a reference path, users should use transformJobName: sfn.Data.stringAt('$.jobName'). Reference: https://github.com/awslabs/aws-cdk/blob/921dcc9f9f569331467a924ca4d849e501a3a557/packages/%40aws-cdk/aws-stepfunctions-tasks/test/sagemaker-transform-job.test.ts#L145

[tonyhoo]

Thanks @wqzoww , tried it out and works fine. Great! Is this gotcha captured anywhere in CDK documentation in case anyone else encounter the same problem?

[nija-at]

@tonyhoo - we have this documented here - https://docs.aws.amazon.com/cdk/api/latest/docs/aws-stepfunctions-readme.html#task-parameters-from-the-state-json