CODEWITHSUNDEEP
amazon-web-servicespython-3.6aws-cloudformationamazon-sqsaws-step-functions
Carlos
Carlos

Reputation: 935

AWS SQS trigger Step Functions

Quick question: Is it possible to trigger the execution of a Step Function after an SQS message was sent?, if so, how would you specify it into the cloudformation yaml file?

Thanks in advance.

Upvotes: 47

Views: 57482

Answers (2)

Justin Callison
Justin Callison

Reputation: 2189

EventBridge Pipes (launched at re:Invent 2022) allows you to trigger Step Functions State Machines without need for a Lambda function.

https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-pipes.html

You can find an example here:

https://github.com/aws-samples/aws-stepfunctions-examples/blob/main/sam/demo-trigger-stepfunctions-from-sqs/template.yaml

Upvotes: 26

Matthew Pope
Matthew Pope

Reputation: 7669

The first think to consider is this: do you really need to use SQS to start a Step Functions state machine? Can you use API gateway instead? Or could you write your messages to a S3 bucket and use the CloudWatch events to start a state machine?

If you must use SQS, then you will need to have a lambda function to act as a proxy. You will need to set up the queue as a lambda trigger, and you will need to write a lambda that can parse the SQS message and make the appropriate call to the Step Functions StartExecution API.

I’m on mobile, so I can’t type up the yaml right now, but if you need it, I can try to update with it later. For now, here is detailed walkthrough of how to invoke a Step Functions state machine from Lambda (including example yaml), and here is walkthrough of how to use CloudFormation to set up SQS to trigger a Lambda.

Upvotes: 67

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