Terraform Core Version

1.7.4

AWS Provider Version

5.36.0

Affected Resource(s)

aws_lb_listener data source

Expected Behavior

It should fill the default_action.target_group_arn attribute in an aws_lb_listener data source even if the type is forward.

Actual Behavior

the target_group_arn value is an empty string

Relevant Error/Panic Output Snippet

No response

Terraform Configuration Files

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "> 5.36"
    }
  }
  required_version = "~> 1.0"
}


provider "aws" {
  region = "<REGION>"
}


data "aws_lb_listener" "prod-listener" {
  load_balancer_arn = "<FILL_THE_ARN>"
  port              = 443
}

output "target_group" {
	value = one(data.aws_lb_listener.prod-listener.default_action[*].target_group_arn)
}

Steps to Reproduce

If you pin the version to < 5.36.0 then the proper target_group_arn is returned, but starting from 5.36.0, there is only an empty string.

Debug Output

No response

Panic Output

No response

Important Factoids

No response

References

The error was introduced in this PR: #35671

Would you like to implement a fix?

Yes