[stepfunctions-tasks] Broken example code

[kafka399]

❓ General Issue

https://docs.aws.amazon.com/cdk/api/latest/python/aws_cdk.aws_stepfunctions_tasks.README.html

The Question

According the official AWS documentation, the following code should work:

    vpc = ec2.Vpc.from_lookup(stack, "Vpc",
        is_default=True
    )
    run_task = tasks.EcsRunTask(stack, "RunFargate",
        integration_pattern=sfn.IntegrationPattern.RUN_JOB,
        cluster=cluster,
        task_definition=task_definition,
        container_overrides=[ContainerOverride(
            container_definition=container_definition,
            environment=[TaskEnvironmentVariable(name="SOME_KEY", value=sfn.JsonPath.string_at("$.SomeKey"))]
        )],
        launch_target=tasks.EcsFargateLaunchTarget()
    )

However, I'm getting the following error:

    jsii.errors.JSIIError: There are no 'Private' subnet groups in this VPC. Available types: Public

I can add the following, but it just pushing the problem into StepFunction task, where subnets are created empty:

    subnets=ec2.SubnetSelection(subnets=vpc.private_subnets)

Can you update the documentation with working code?

Environment

• CDK CLI Version: 1.66.0 (build 459488d)
• Module Version:
• Node.js Version: v10.15.3
• OS: OSX Mojave
• Language (Version): Python (3.7.3)

Other information

[kafka399]

The following code allows to create a StepFunction task

   run_task = sf_task.EcsRunTask(self, "RunFargate",
                                        integration_pattern=sfn.IntegrationPattern.RUN_JOB,
                                        cluster=cluster,
                                        task_definition=task_def,
                                        **assign_public_ip=True,**
    .....)

However, the question remains, why docs provide a broken solution.

[shivlaks]

thanks for reporting @kafka399 - I'll update the example (or happy to accept a PR if you want to open one!)
as for why there's a broken example - it's likely an oversight as it was some reused code plugged in to the README from a unit test.

[doodlesbykumbi]

@kafka399 @shivlaks If I understood the solution correctly (which seems very simple) then here's a PR #11028

[github-actions]

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