CODEWITHSUNDEEP
amazon-web-servicesaws-lambda
Victor
Victor

Reputation: 23972

Send a request if Amazon Lambda function is successful or unsuccessful

My Amazon Lambda function (in Python) is called when an object 123456 is created in S3's input_bucket, do a transformation in the object and saves it in output_bucket.

I would like to notify my main application if the request was successful or unsuccessful. For example, a POST http://myapp.com/successful/123456 if the processing is successful and http://myapp.com/unsuccessful/123456 if its not.

One solution I thought is to create a second Amazon Lambda function that is triggered by a put event in output_bucket, and it to do the successful POST request. This solves half of the problem because but I can't trigger the unsuccessful POST request.

Maybe AWS has a more elegant solution using a parameter in Lambda or a service that deals with these types of notifications. Any advice or point in the right direction will be greatly appreciated.

Upvotes: 0

Views: 1007

Answers (2)

Ashan
Ashan

Reputation: 19758

Few possible solutions which I see as elegant

  • Using SNS Topic: From your transformation lambda, trigger a SNS topic, with success/unsuccess message, where SNS will call a HTTP/HTTPS endpoint with message payload. The advantage here is, your transformation lambda is loosely coupled with endpoint trigger and only connected through messaging.
  • Using Lambda Step Functions:

    You could arrange to run a Lambda function every time a new object is uploaded to an S3 bucket. This function can then kick off a state machine execution by calling StartExecution. The advantage in using step functions is that you can coordinate the components of your application as series of steps in a visual workflow.

Upvotes: 2

kosa
kosa

Reputation: 66667

I don't think there is any elegant AWS solution, unless you re-architect, something like your lambda sends message to SQS or some intermediatery messaging service with STATUS and then interemdeiatery invokes POST to your application.

If you still want to go with your way of solving, you might need to configure "DeadLetter queue" to do error handling in failure cases (note that use cases described here are not comprehensive, so need to make sure it covers your case) like described here.

Upvotes: 1

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