Make node_pool_labels, node_pool_tags, and node_pool_taints all optional

[morgante]

Desired flow:

1. Defaults are available for the entire variable.
2. I can override the variable for one node pool without having to set a value for the whole variable.

[kiran002]

Could you elaborate a bit more? Because from the definition all of these variable seem to have default values (https://github.com/terraform-google-modules/terraform-google-kubernetes-engine/blob/master/variables.tf#L167-L170) and if i am not wrong, that should enough correct?

[morgante]

This might be out of date, but the specific desire is:

1. Defaults are available for the entire variable.
2. I can override the variable for one node pool without having to set a value for the whole variable.

[evkuzin]

@morgante @aaron-lane It could be move to done actually.
Now you could just add block of tags/labels/taints with name of pool and it will not affect other pools

variable "node_pools_labels" {
  type        = map(map(string))
  description = "Map of maps containing node labels by node-pool name"

  default = {
    all               = {}
    default-node-pool = {}
  }
}

[morgante]

@evkuzin What if I have a custom node pool? Do I have to set the node_pools_labels to set an empty map for that custom pool.

[evkuzin]

@morgante exactly you need to create object inside node_pools_labels with name equal to node pool name and set it to {}

labels = merge(
      {
        "cluster_name" = var.name
      },
      {
        "node_pool" = var.node_pools[count.index]["name"]
      },
      var.node_pools_labels["all"],
      var.node_pools_labels[var.node_pools[count.index]["name"]],
    )

[morgante]

So this has not been fixed.

As stated in the original issue, the ask is that I don't have to specify node_pools_labels at all if I don't want to set any custom labels.

[evkuzin]

Okay, I understand now.

[naseemkullah]

I find myself having to do this with clusters whose default-pool is deleted and custom pools default and preemptible are added.

  node_pools_metadata = {
    all         = {}
    default     = {}
    preemptible = {}
  }

  node_pools_labels = {
    all = {
      env = var.env
    }
    default     = {}
    preemptible = {}
  }

  node_pools_taints = {
    all         = []
    default     = []
    preemptible = []
  }

  node_pools_tags = {
    all         = []
    default     = []
    preemptible = []
  }

My understanding is that #269 will allow me to not specify the empty values, is that correct?