Add quickstart sample for private AKS cluster with custom DNS

quickstart/301-aks-private-cluster/variables.tf

@@ -0,0 +1,65 @@
+variable resource_group_name {
+  type        = string
+  description = "Name of the Azure resource group"
+  default     = "aks-quickstart"
+}
+
+variable cluster_name {
+  type        = string
+  description = "Name of the AKS cluster"
+  default     = "demo-private"
+}
+
+variable custom_dns {
+  type        = string
+  description = "IP of custom DNS server"
+  default     = "168.63.129.16"
+}
+
+variable custom_dns_vnet_id {
+  type        = string
+  description = "Resource ID of the Azure VNet that holds custom DNS server"
+  default     = ""
+}
+
+variable "client_id" {
+  type        = string
+  description = "The service principal ID"
+  default     = "<client-id>"
+}
+
+variable "client_secret" {
+  type        = string
+  description = "The service principal password"
+  default     = "<client-secret>"
+}
+
+variable "agent_count" {
+  type        = string
+  description = "The number of K8S nodes to provision"
+  default     = 3
+}
+
+variable "kubernetes_version" {
+  type        = string
+  description = "The version of K8S to provision"
+  default     = "1.17.9"
+}
+
+variable "ssh_public_key" {
+  type        = string
+  description = "The SSH public key of K8S nodes"
+  default     = "~/.ssh/id_rsa.pub"
+}
+
+variable "dns_prefix" {
+  type        = string
+  description = "The DNS prefix"
+  default     = "aks"
+}
+
+variable location {
+  type        = string
+  description = "The location"
+  default     = "East US"
+}