given key is not an element when using latest private-cluter

[endorama]

I'm tring to setup a private cluster, using the private-cluster module.

Unfortunately an error comes up and I've not been able to find it's root cause.

I'm using this module at version 7.0.0

The error is:

Error: Invalid index

  on .terraform/modules/cluster/terraform-google-modules-terraform-google-kubernetes-engine-7be707a/modules/private-cluster/main.tf line 100, in locals:
 100:   cluster_endpoint = var.enable_private_nodes ? (var.deploy_using_private_endpoint ? google_container_cluster.primary.private_cluster_config.0.private_endpoint : google_container_cluster.primary.private_cluster_config.0.public_endpoint) : google_container_cluster.primary.endpoint
    |----------------
    | google_container_cluster.primary.private_cluster_config is empty list of object

The given key does not identify an element in this collection value.

My usage of the module is:

module "cluster" {
  # source  = "terraform-google-modules/kubernetes-engine/google"
  source  = "terraform-google-modules/kubernetes-engine/google//modules/beta-private-cluster"
  version = "~> 7.0"

  project_id         = local.google_project
  name               = local.cluster_name
  kubernetes_version = "1.15.8-gke.2"
  regional           = true
  region             = var.cluster_location
  zones              = var.cluster_zones

  remove_default_node_pool = true
  maintenance_start_time   = "04:00"
  http_load_balancing      = false
  grant_registry_access    = true

  enable_private_nodes          = true
  enable_private_endpoint       = false
  deploy_using_private_endpoint = false

  network    = module.network.network_name
  subnetwork = "${local.cluster_name}-subnet-${var.cluster_location}"

  ip_range_pods     = "${local.cluster_name}-subnet-${var.cluster_location}-pods"
  ip_range_services = "${local.cluster_name}-subnet-${var.cluster_location}-services"

  master_authorized_networks = [
    { cidr_block = "[REDACTED]", display_name = "[REDACTED]" }
  ]
}

Any hint on how to fix it or where to look for further debug? Thanks!

[morgante]

Thanks for the report. It looks like the error is on this line.

Could you try this fix (and regenerate the modules)?

-  cluster_endpoint = var.enable_private_nodes ? (var.deploy_using_private_endpoint ? google_container_cluster.primary.private_cluster_config.0.private_endpoint : google_container_cluster.primary.private_cluster_config.0.public_endpoint) : google_container_cluster.primary.endpoint
+  cluster_endpoint = (var.enable_private_nodes && length(google_container_cluster.primary.private_cluster_config) > 0) ? (var.deploy_using_private_endpoint ? google_container_cluster.primary.private_cluster_config.0.private_endpoint : google_container_cluster.primary.private_cluster_config.0.public_endpoint) : google_container_cluster.primary.endpoint

[endorama]

@morgante it works! Both plan and apply worked as expected.

[endorama]

I'd like to understand in what case google_container_cluster.primary.private_cluster_config may be empty. 🤔

I was expecting that block to be set when enable_private_nodes is true, but that does not seem the case? (I'm still new to the dynamic Terraform syntax)

[morgante]

Truth be told, I'm not quite sure how/when it ends up being empty either. I'm guessing it has something to do with changing the value of enable_private_nodes to true.

In either case, I think it's good to have this failsafe.