service/cloudwatchevents: Handling for RemoveTargets failure entries and eventual consistency

[bflad]

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Closes #1479
Reference: https://docs.aws.amazon.com/eventbridge/latest/userguide/
Reference: https://docs.aws.amazon.com/eventbridge/latest/APIReference/API_RemoveTargets.html

Release note for CHANGELOG:

* resource/aws_cloudwatch_event_rule: Retry deletion on CloudWatch Events Target deletion eventual consistency
* resource/aws_cloudwatch_event_target: Return failed entry error code and message if provided in RemoveTargets response

In practice it appears there is some eventual consistency issues between removing CloudWatch Events Targets and associated CloudWatch Events Rules successfully deleting. This change introduces retry logic into the aws_cloudwatch_event_target resource deletion to potentially mitigate the observed service behavior.

The choice of five minutes for this deletion timeout is arbitrary. The only guidance on the subject is this information in the RemoveTargets API Reference:

When you remove a target, when the associated rule triggers, removed targets might continue to be invoked. Allow a short period of time for changes to take effect.

The RemoveTargets API reference also notes:

This action can partially fail if too many requests are made at the same time. If that happens, FailedEntryCount is non-zero in the response and each entry in FailedEntries provides the ID of the failed target and the error code.

Since it appears failures can occur even with "successful" API calls, we now will return the failures found in the API response, if non-empty, to operators as an error. These error entries should allow additional insight if the resource deletion is unsuccessful due to operator issues or potential temporary conditions that we should further mitigate within the resource itself.

Output from acceptance testing:

--- PASS: TestAccAWSCloudWatchEventRule_basic (31.84s)
--- PASS: TestAccAWSCloudWatchEventRule_description (30.48s)
--- PASS: TestAccAWSCloudWatchEventRule_IsEnabled (43.99s)
--- PASS: TestAccAWSCloudWatchEventRule_pattern (31.63s)
--- PASS: TestAccAWSCloudWatchEventRule_prefix (17.09s)
--- PASS: TestAccAWSCloudWatchEventRule_role (31.03s)
--- PASS: TestAccAWSCloudWatchEventRule_tags (43.22s)

--- PASS: TestAccAWSCloudWatchEventTarget_basic (34.50s)
--- PASS: TestAccAWSCloudWatchEventTarget_batch (99.43s)
--- PASS: TestAccAWSCloudWatchEventTarget_ecs (32.80s)
--- PASS: TestAccAWSCloudWatchEventTarget_ecsWithBlankTaskCount (33.34s)
--- PASS: TestAccAWSCloudWatchEventTarget_full (75.19s)
--- PASS: TestAccAWSCloudWatchEventTarget_input_transformer (43.14s)
--- PASS: TestAccAWSCloudWatchEventTarget_kinesis (75.03s)
--- PASS: TestAccAWSCloudWatchEventTarget_missingTargetId (19.97s)
--- PASS: TestAccAWSCloudWatchEventTarget_sqs (20.25s)
--- PASS: TestAccAWSCloudWatchEventTarget_ssmDocument (20.81s)

[rsareth]

Please, merge it. I'm facing the issue right now ! I can't delete the cloudwatch event because of the exisiting target.

[ryndaniels]

👍

--- PASS: TestAccAWSCloudWatchEventRule_prefix (14.68s)
--- PASS: TestAccAWSCloudWatchEventTarget_sqs (15.46s)
--- PASS: TestAccAWSCloudWatchEventTarget_missingTargetId (15.88s)
--- PASS: TestAccAWSCloudWatchEventTarget_ecs (18.23s)
--- PASS: TestAccAWSCloudWatchEventTarget_ecsWithBlankTaskCount (18.56s)
--- PASS: TestAccAWSCloudWatchEventTarget_ssmDocument (18.87s)
--- PASS: TestAccAWSCloudWatchEventRule_pattern (20.04s)
--- PASS: TestAccAWSCloudWatchEventRule_description (20.85s)
--- PASS: TestAccAWSCloudWatchEventTarget_basic (20.98s)
--- PASS: TestAccAWSCloudWatchEventRule_basic (21.30s)
--- PASS: TestAccAWSCloudWatchEventRule_IsEnabled (25.34s)
--- PASS: TestAccAWSCloudWatchEventRule_tags (26.01s)
--- PASS: TestAccAWSCloudWatchEventRule_role (29.76s)
--- PASS: TestAccAWSCloudWatchEventTarget_input_transformer (35.04s)
--- PASS: TestAccAWSCloudWatchEventTarget_kinesis (63.12s)
--- PASS: TestAccAWSCloudWatchEventTarget_full (63.76s)
--- PASS: TestAccAWSCloudWatchEventTarget_batch (80.07s)

[ghost]

This has been released in version 2.45.0 of the Terraform AWS provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

For further feature requests or bug reports with this functionality, please create a new GitHub issue following the template for triage. Thanks!

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

If you feel this issue should be reopened, we encourage creating a new issue linking back to this one for added context. Thanks!