Can a lambda in an AWS Step Function know the name of the step it is in?

Question

For a lambda executed within a step function, I kind of expected that I could get the name of the current step from the lambda context, but it doesn't seem to be that simple.

Is there any way to get the name of the current step in a lambda that is executed within a Step Function?

Answer 1

Based on the documentation, I was using Parameters and $$ to pass the step function context object into my lambda function. To test and see if it was working, I thought I could go to the step function console, start a new execution and see the context object being passed into the step function on the "Step Input" tab. To my dismay, it wasn't displayed there. I added some diagnostic logging to the lambda function serializing the input to JSON and logging out to CloudWatch. Cloudwatch logs showed that the context object was being passed in.

Anyway, thought I would post this here to maybe help someone avoid the time I spent trying to figure this one out. It gets passed in, just doesn't show up in the step function console.

Answer 2

AWS Step Functions released Context Object where you can access information about your execution.

You can use it to send the execution arn to your lambda.

https://docs.aws.amazon.com/step-functions/latest/dg/input-output-contextobject.html