circular dependency between aws_lb_listener_rule and aws_lb_target_group when replacing aws_lb_target_group

[khumps]

When trying to do anything that causes the target group to be replaced (changing the name, port, etc) It detects that the listener rule can be updated in place but the target group can not be deleted until the listener rule is not depending on it.

The output of the terraform plan/apply is https://pastebin.com/yN6tHvM8 and will result in the provider timing out trying to delete the target group due to the relationship to the listener rule. To fix this, any change to listener_rule.target_group_arn needs to force replacement of the listener rule

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Terraform CLI and Terraform AWS Provider Version

Terraform v1.0.4
on darwin_amd64

• provider registry.terraform.io/hashicorp/aws v3.48.0
• provider registry.terraform.io/hashicorp/template v2.2.0

Affected Resource(s)

aws_lb_listener_rule
aws_lb_target_group

Terraform Configuration Files

resource "aws_lb_target_group" "my_target_group" {
  name     = NAME
  port     = PORT
  protocol = "HTTP"
  vpc_id   = VPC_ID
}

resource "aws_lb_listener_rule" "my_listener_rule" {
  listener_arn = var.listener_arn

  action {
    type             = "forward"
    target_group_arn = aws_lb_target_group.my_target_group.arn
  }

  condition {
    host_header {
      values = ["DOMAIN_NAME"]
    }
  }
}

Terraform logs (with TF_LOG=DEBUG)

https://pastebin.com/CZzrTSEc

[khumps]

I believe this would be fixed by adding ForceNew: true here

[justinretzolk]

Hey @khumps 👋 Thank you for taking the time to file this issue. Can you update the issue description with debug output as well so that we have all of the information necessary to investigate this?

Additionally, it looks like you may have redacted/changed some of the Terraform config, based on the output you provided (totally understand needing to do this sometimes!). Can you confirm whether aws_lb_listener_rule.my_listener_rule.action.target_group_arn is an interpolation of the other resource, or is a hardcoded ARN?

[khumps]

Hey @khumps 👋 Thank you for taking the time to file this issue. Can you update the issue description with debug output as well so that we have all of the information necessary to investigate this?

Additionally, it looks like you may have redacted/changed some of the Terraform config, based on the output you provided (totally understand needing to do this sometimes!). Can you confirm whether aws_lb_listener_rule.my_listener_rule.action.target_group_arn is an interpolation of the other resource, or is a hardcoded ARN?

Hey Justin, I can definitely get some debug input when I get in tomorrow. LISTENER_ARN and TARGET_ARN are both just substitutions to redact code. in code they actually are a direct reference to a terraform resource. I have updated OP to be a little clearer on that

[khumps]

@justinretzolk I have appended the relevant part of the debug logs to OP

[lindlaaa]

Any update on this? Having a similar issue but with a Listener instead of a Rule.