Overriding command in AWS Fargate task in AWS Step Function

Question

The aim is to have an AWS state machine that runs an AWS Fargate task with a custom command. Per AWS docs , the command in the Docker image of the Fargate task may be overridden by having

"Overrides": {
    "ContainerOverrides": [{
        "Name": "container-name",
        "Command.$": "$.commands"
    }]
}

as one item of "Parameters" . Note the .$ after Command .

I want to build the state machine with AWS CDK. Per CDK Docs , I can pass a container override, see parameter container_overrides , which expects a sequence of values of type ContainerOverride as value. In one such ContainerOverride I can specify the command to executed. When I do that, I end up getting

"Overrides": {
    "ContainerOverrides": [{
        "Name": "container-name",
        "Command": ["$.commands"]
    }]
}

as one item of "Parameters" . The key of the command item should include .$ and the value shouldn't be a list.

My question is: how to parameterize aws_cdk.aws_stepfunctions_tasks.EcsRunTask such that the desired "Parameters" item is obtained.

Answer 1

Answering my own question based on this information.

Consider the objective to use AWS CDK to pass the items of the value of {"command": ["arg1", "arg2"]} as command line arguments to a Fargate task inside a step function task. This may be achieved as follows:

from aws_cdk import aws_stepfunctions, aws_stepfunctions_task

aws_stepfunctions_tasks.EcsRunTask(
    ...,
    container_overrides=[
        aws_stepfunctions_tasks.ContainerOverride(
           container_definition=aws_stepfunctions.StateMachine(...),
           command=aws_stepfunctions.JsonPath.list_at("$.command")
        )
    ],
    ...
)