Possibility to setup SNS dead letter queue for Lambda Function?

[MaartenThoelen]

❓ Possibility to setup SNS dead letter queue for Lambda Function?

The Question

Is it possible to setup an SNS dead letter queue for a Lambda Function using the AWS CDK?
It looks like only SQS dead letter queues are supported.

Environment

• CDK CLI Version: 1.15.0 (build bdbe3aa)
• Module Version: ^1.15.0
• OS: OSX Mojave
• Language: TypeScript

[nmussy]

Hey @MaartenThoelen,

I'm not sure I understand what you mean by SNS dead letter queue. Unlike SQS, SNS delivers its messages synchronously to its subscribers.

There is a feature to log the delivery status in SQS or to a Lambda, but it's currently not implemented in CloudFormation. You can track its progress on the roadmap: cloudformation-coverage-roadmap#66

[MaartenThoelen]

Hi @nmussy ,

I am trying to replicate the same behavior as I did before with an AWS SAM template.
See the attachment below for a snippet from the original template.

[nmussy]

Ah, I see, sorry. The CDK documentation only accepts an SQS queue, but the CloudFormation
AWS::Lambda::Function DeadLetterConfig property docs says:

The Amazon Resource Name (ARN) of an Amazon SQS queue or Amazon SNS topic.

I'll make a PR to fix this issue. In the meantime, you should be able to circumvent the issue using an escape hatch. Tell me if you need more info.

Just as an FIY, there's also a package for SAM if you want to keep using it, see aws-sam's CfnFunction.deadLetterQueue

[MaartenThoelen]

Great!

Thanks for the info.

[nmussy]

Duplicate of #2739