(aws-cdk-lib/aws-events-targets): `EventBus` target construct does not support `retryAttempts` or `maxEventAge`

[mattvalleycodes]

Describe the feature

Unlike other target constructs, including but not limited to LambdaFunction or SfnStateMachine, the EventBus target construct does not support the retryAttempts or maxEventAge props.

By looking at the ref CloudFormation doc for the AWS::Events::Rule, I can see that it does indeed support Retry Policy. Considering other target constructs support this feature, it would be good to have it implemented for EventBus as well.

Use Case

We're using EventBridge heavily to implement our event-oriented architecture following the Hub & Spoke pattern. Each business domain has a dedicated Event Bridge that uses a Rule to push events to the centralised Hub event bridge. Right now, we rely on the default retry policy (as we don't have a way to customise it via CDK). The issue is that the default 24 hours is way too long for us, we would like the fail procedure to complete significantly faster, for example in 10 minutes. The issue is that the default 24 hours is way too long for us; we would like the fail procedure to complete significantly faster, for example, in 10 minutes.

Proposed Solution

• Leverage the existing TargetBaseProps interface to support the new props
• Leverage the existing bindBaseTargetConfig to inject the new retryPolicy using the provided input

Other Information

No response

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

CDK version used

2.121.1

Environment details (OS name and version, etc.)

Mac OS Sonomo 14.2.1 (23C71)

[pahud]

Thank you for the feature request and we welcome and appreciate your PRs.

[mattvalleycodes]

@pahud Great! I should be able to file a PR for this soon.

[rrhodes]

When I tried this in the past I learned that we could not set a retry policy on event bus targets, unlike other targets. I'm struggling to find documentation for that limitation.

When I set an event bus as the target and attempted to create a retry policy, CloudFormation raised an error indicating the retry policy had to be 24 hours / 185 attempts (the default).