I'm launching a GKE private cluster via terraform template and getting the following error

   Error: Error loading ~/projects/tf-gke/variables.tf: Variable 'private_cluster_config' type must be one of [string, map, list] - 'bool' is not a valid type

However according to their docs 'bool' type should exist https://www.terraform.io/docs/configuration/variables.html#bool

My providers.tf file looks like this

provider "google" {
version = "~> 2.3"
project = "fantastic-cluster"
region = "australia-southeast1" }