default node pool

 default_node_pool {
   name       = "default"
   node_count = var.node_count
   vm_size    = "Standard_A2_v2"
 }

os_sku
Terraform AKS module: enable auto scaling

Terraform AKS, azurerm_resource_group, azurerm_kubernetes_cluster, azurerm_role_assignment, azurerm_virtual_network, azurerm_dns_zone