Specifying name_prefix in aws_cloudwatch_event_rule causes resource to be created twice

[otterley]

Summary

Specifying name_prefix instead of name as a parameter to an aws_cloudwatch_event_rule causes the provider to create the resource twice. One of them, however, will be orphaned by Terraform and will not be tracked in the state, leaving the Rule configured with CloudWatch even after a destroy operation until manually deleted by the user.

Terraform Version

Terraform v0.11.7

• provider.aws v1.18.0

Affected Resource(s)

• aws_cloudwatch_event_rule

Terraform Configuration Files

resource "aws_cloudwatch_event_rule" "ebs_backup" {
  name_prefix         = "ebs-backup-"
  # note: using "name" instead cures the problem
  description         = "Back up ${var.volume_name} every ${var.frequency}"
  schedule_expression = "rate(${var.frequency})"
  is_enabled          = "${var.enable_event_rule}"
}

Expected Behavior

A single CloudWatch Event Rule should be created with the specified name prefix.

Actual Behavior

Two CloudWatch Event Rules are created with the specified name prefix.

Steps to Reproduce

Declare a resource similar to the one above and apply it.

[bflad]

Thanks for reporting this. Bug fix pull request submitted: #4579

[bflad]

The fix for this will release with v1.20.0 of the AWS provider, likely later today. 👍

[bflad]

This has been released in version 1.20.0 of the AWS provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

[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!