enabled = 'false' causes "Resource 'null_resource.default' not found for variable 'null_resource.default.triggers.x''

[lestephane]

When i use enabled = "false":

module "mylabel" {
  enabled = "false"
  source = "git::https://github.com/cloudposse/terraform-null-label.git?ref=0.3.1"
  namespace = "${var.namespace}"
  stage = "${var.stage}"
  name = "${var.cname_label}"
  tags = "${module.infrastructure.default_tags}"
}

I get errors because the module outputs refer to a resource that is not present when enabled is false:

Error: Error running plan: 7 error(s) occurred:

* module.mylabel.output.id: Resource 'null_resource.default' not found for variable 'null_resource.default.triggers.id'
* module.mylabel.output.attributes: Resource 'null_resource.default' not found for variable 'null_resource.default.triggers.attributes'
* module.mylabel.output.tags: Resource 'null_resource.default' not found for variable 'null_resource.default.triggers.id'
* module.mylabel.output.stage: Resource 'null_resource.default' not found for variable 'null_resource.default.triggers.stage'
* module.mylabel.output.name: Resource 'null_resource.default' not found for variable 'null_resource.default.triggers.name'
* module.mylabel.output.namespace: Resource 'null_resource.default' not found for variable 'null_resource.default.triggers.namespace'

terragrunt -version

terragrunt version v0.13.23

terraform -version

Terraform v0.11.1

[aknysh]

@lestephane thank you for testing the module and reporting the issue.
It's a known issue in the new versions of Terraform.

They made it a fatal error in 0.11.0 to reference a resource with count=0 even if that recource is not used.
hashicorp/terraform#16726

But then switched it to warning in 0.11.1
https://github.com/hashicorp/terraform/blob/v0.11.1/CHANGELOG.md

Since the new feature was already rolled out, and since development for 0.12 depends on the foundational changes that enabled it, we decided to compromise with an opt-out mechanism in 0.11.1, so those with configurations containing problematic output expressions have a means to use 0.11.1 without first fixing all modules. We understand that this is not the most ideal migration path -- if we could do this over again we would've introduced the warning in one of the 0.10 point releases -- but we hope that this compromise is acceptable so that we can continue to make progress towards 0.12.

To enable that behavior, you need to set the variable TF_WARN_OUTPUT_ERRORS=1

They mentioned they will make it an error again in 0.12, so it's a temporarily fix anyway.

But if they fix ternaries (to short-circuit and not evaluate left and right part at the same time), we can work around the issue very easily
hashicorp/hil#50

Since you mentioned you are using Terraform 0.11.1, could you please try to set TF_WARN_OUTPUT_ERRORS=1 and test again?

Thank you

[lestephane]

Thanks for the detailed explanation. Terraform has rough edges around conditionals, not just ternary operator, but also conditional modules (module counts) are not supported. I'll stay away from using conditionals for now.

…

On Thu, Dec 7, 2017 at 6:54 PM, Andriy Knysh ***@***.***> wrote: @lestephane <https://github.com/lestephane> thank you for testing the module and reporting the issue. It's a known issue in the new versions of Terraform. They made it a fatal error in 0.11.0 to reference a resource with count=0 even if that recource is not used. hashicorp/terraform#16726 <hashicorp/terraform#16726> But then switched it to warning in 0.11.1 https://github.com/hashicorp/terraform/blob/v0.11.1/CHANGELOG.md Since the new feature was already rolled out, and since development for 0.12 depends on the foundational changes that enabled it, we decided to compromise with an opt-out mechanism in 0.11.1, so those with configurations containing problematic output expressions have a means to use 0.11.1 without first fixing all modules. We understand that this is not the most ideal migration path -- if we could do this over again we would've introduced the warning in one of the 0.10 point releases -- but we hope that this compromise is acceptable so that we can continue to make progress towards 0.12. To enable that behavior, you need to set the variable TF_WARN_OUTPUT_ERRORS=1 They mentioned they will make it an error again in 0.12, so it's a temporalily fix anyway. But if they fix ternaries (to short-circuit and not evaluate left and right part at the same time), we can work around the issue very easily hashicorp/hil#50 <hashicorp/hil#50> Since you mentioned you are using Terraform 0.11.1, could you please try to set TF_WARN_OUTPUT_ERRORS=1 and test again? Thank you — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#14 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AFNTlMTA0fussoZGWHyC36hxM8uGALh9ks5s-CZggaJpZM4Q5xx4> .

[aknysh]

@lestephane let us know if you have any other questions or concerns, we'll try to address them