gist for blog post - https://pradeeploganathan.com/?p=5886&preview=true

variables.tf

variable "resource_prefix" {
  type        = string
  description = "(Required) Prefix given to all resources within the module."
}

variable "location" {
  type        = string
  description = "(Required) Specifies the supported Azure location where the resource exists. Changing this forces a new resource to be created."
}

variable "kubernetes_version" {
  type        = string
  default     = "1.16.8"
  description = "Version of Kubernetes specified when creating the AKS managed cluster. If not specified, the latest recommended version will be used at provisioning time (but won't auto-upgrade)."
}

variable "tags" {
  type        = map
  default     = {}
  description = "Set of base tags that will be associated with each supported resource."
}