(step-functions): Dynamic passing of bucket and prefix to result writer of distributed map

[Nicolas-SB]

Describe the feature

Analogous to #29409, which was solved in #31619, I would like to pass sfn.JsonPaths to sfn.ResultWriter(bucket=[...], prefix=[...]). Currently I have to know the bucket and can not read it dynamically from the input event.

Use Case

I want to define my state machine using CDK and use all features of the Distributed Map

Proposed Solution

Create a Result Writer that can take a string in place of a bucket.

Example cdk code in python:

my_map = sfn.DistributedMap(
    scope=self,
    id="my_id",
    item_reader=sfn.S3JsonItemReader(
        bucket_name_path=sfn.JsonPath.string_at("$.manifest_bucket"),
        key=sfn.JsonPath.string_at("$.input_manifest_key"),
    ),
    result_writer=sfn.ResultWriter(
        bucket_name_path=sfn.JsonPath.string_at("$.manifest_bucket"),
        prefix=sfn.JsonPath.string_at("$.distributed_map_result_prefix"),
    ),
)

Other Information

No response

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

CDK version used

2.173.2

Environment details (OS name and version, etc.)

macOS Sequoia 15.2

[pahud]

Thank you for the feature request. We welcome and appreciate your PR for this.