can't provision a cluster with less than than 2 "zones"

[czka]

$ terraform --version
Terraform v0.11.11
+ provider.google v1.19.1

With code as pasted in the bottom-most section of this ticket, which seems valid as per your docs and examples, I'm getting the following error at terraform plan:

Error: Error running plan: 1 error(s) occurred:

* module.gke.local.cluster_type_output_zonal_zones: local.cluster_type_output_zonal_zones: Resource 'google_container_cluster.zonal_primary' does not have attribute 'additional_zones' for variable 'google_container_cluster.zonal_primary.*.additional_zones'

Why is user forced to specify more than 1 zone? This is supposed to be a generic module after all.

variable "default-scopes" {
  type = "list"

  default = [
    "https://www.googleapis.com/auth/monitoring",
    "https://www.googleapis.com/auth/devstorage.read_only",
    "https://www.googleapis.com/auth/logging.write",
    "https://www.googleapis.com/auth/service.management.readonly",
    "https://www.googleapis.com/auth/servicecontrol",
    "https://www.googleapis.com/auth/trace.append",
  ]
}

module "gke" {
  source                     = "github.com/terraform-google-modules/terraform-google-kubernetes-engine?ref=master"
  ip_range_pods              = ""                 #TODO
  ip_range_services          = ""                 #TODO
  name                       = "cluster-you-name-it"
  network                    = "vpc-you-name-it"
  project_id                 = "project-you-name-it"
  region                     = "europe-west1"
  subnetwork                 = "vpc-sub-you-name-it"
  zones                      = ["europe-west1-c"]
  monitoring_service         = "monitoring.googleapis.com/kubernetes"
  logging_service            = "logging.googleapis.com/kubernetes"
  maintenance_start_time     = "04:00"
  kubernetes_version         = "1.11.3-gke.18"
  horizontal_pod_autoscaling = true
  regional                   = false

  node_pools = [
    {
      name               = "core"
      machine_type       = "n1-standard-2"
      oauth_scopes       = "${var.default-scopes}"
      min_count          = 1
      max_count          = 20
      auto_repair        = true
      auto_upgrade       = false
      initial_node_count = 20
    },
    {
      name               = "cc"
      machine_type       = "custom-6-23040"
      oauth_scopes       = "${var.default-scopes}"
      min_count          = 0
      max_count          = 20
      auto_repair        = true
      auto_upgrade       = false
      initial_node_count = 20
      preemptible        = true
      node_version       = "1.10.9-gke.7"
    },
  ]

  node_pools_labels = {
    all  = {}
    core = {}
    cc   = {}
  }

  node_pools_tags = {
    all  = []
    core = []
    cc   = []
  }

  node_pools_taints = {
    all  = []
    core = []
    cc   = []
  }
}

[morgante]

I don't think it's supported to have a regional cluster with a single zone. For that case, I think you would want to create a zonal cluster, as per this example: https://github.com/terraform-google-modules/terraform-google-kubernetes-engine/tree/master/examples/simple_zonal

[czka]

@morgante Why do you think I want to have a regional cluster? I've set regional = false.

[bzub]

I'm hitting this issue as well, although it only started happening after a terraform destroy in which the previously created cluster was deleted already outside of terraform (gcloud cli). So there may be some resources left over in my GCP project that get picked up when terraform refreshes. terraform show is empty so I don't think it's a state issue on the terraform side.

[bzub]

Now I'm seeing this issue on a brand new GCP project (created with project-factory module).

[bzub]

This interpolation basically looks for a non-existent list element at index 1 when var.zones has a length of only one.

terraform-google-kubernetes-engine/cluster_zonal.tf

Line 27 in 60baab8

additional_zones = ["${slice(var.zones,1,length(var.zones))}"]

I'm assuming that's part of the issue, since this local variable ends up with no zones instead of the singular zone provided to the module's zone variable.

terraform-google-kubernetes-engine/main.tf

Line 54 in 60baab8

cluster_type_output_zonal_zones = "${concat(google_container_cluster.zonal_primary.*.additional_zones, list(list()))}"

[morgante]

Thanks for identifying the issue - that does indeed look like what needs to be fixed.

[ogreface]

Potential fix in: #50

[czka]

#50 works for me.