ASM module erroring out on a count var

[pramodsetlur]

TL;DR

Error: Invalid count argument

  on .terraform/modules/gke_cluster.asm_managed_control_plane.cpr/main.tf line 57, in resource "random_id" "cache":
  57:   count = (!local.skip_download) ? 1 : 0

The "count" value depends on resource attributes that cannot be determined
until apply, so Terraform cannot predict how many instances will be created.
To work around this, use the -target argument to first apply only the
resources that the count depends on.

Expected behavior

No response

Observed behavior

No response

Terraform Configuration

# Managed ASM inside GKE
module "asm_managed_control_plane" {
  depends_on = [
    google_container_cluster.gke_cluster
  ]
  count = var.asm_managed_control_plane_enabled == true ? 1 : 0
  source                    = "github.com/terraform-google-modules/terraform-google-kubernetes-engine//modules/asm?ref=v21.0.0"
  project_id                = var.project_id
  cluster_name              = var.cluster_name
  cluster_location          = var.region
  enable_cni                = true
  enable_fleet_registration = true
  enable_mesh_feature       = false
}

# The above depends on the below GKE cluster resource.

resource "google_container_cluster" "gke_cluster" {
  provider = google-beta

  name     = var.cluster_name
  location = var.region
  .
  .
  .
}

Terraform Version

Terraform version: "0.14.8"

Additional information

I was initially pointing to master and then updated it to v21.0.0 after #1189 was merged and released. It had been working last week when I created a new cluster with managed ASM control plane, but facing this error now.

[bharathkkb]

Hi @pramodsetlur
I believe this is due to the depends_on block in the asm module.

 depends_on = [
    google_container_cluster.gke_cluster
  ]

#1189 works around this by making the GKE module cluster_name output a computed attribute. You can use the GKE module instead of the google_container_cluster resource or follow a similar approach of making the cluster_name computed.