Use new azurerm_network_interface_backend_address_pool_association

* Require terraform-provider-azurerm v1.17+
* Inline load_balancer_backend_address_pools_ids is deprecated
and scheduled for removal in the v2.0 provider
* hashicorp/terraform-provider-azurerm#2079

CHANGES.md

@@ -18,7 +18,9 @@ Notable changes between versions.
 
 #### Azure
 
-* Add `primary` field to `ip_configuration`. Required by `terraform-provider-azurerm` v1.17+ ([#331](https://github.com/poseidon/typhoon/pull/331))
+* Use new `azurerm_network_interface_backend_address_pool_association`
+  * Require `terraform-provider-azurerm` v1.17+ (action required)
+* Add `primary` field to `ip_configuration` needed by v1.17+ ([#331](https://github.com/poseidon/typhoon/pull/331))
 
 #### Addons
 

azure/container-linux/kubernetes/controllers.tf

@@ -105,12 +105,16 @@ resource "azurerm_network_interface" "controllers" {
 
     # public IPv4
     public_ip_address_id = "${element(azurerm_public_ip.controllers.*.id, count.index)}"
-
-    # backend address pool to which the NIC should be added
-    load_balancer_backend_address_pools_ids = ["${azurerm_lb_backend_address_pool.controller.id}"]
   }
 }
 
+# Add controller NICs to the controller backend address pool
+resource "azurerm_network_interface_backend_address_pool_association" "controllers" {
+  network_interface_id    = "${azurerm_network_interface.controllers.id}"
+  ip_configuration_name   = "ip0"
+  backend_address_pool_id = "${azurerm_lb_backend_address_pool.controller.id}"
+}
+
 # Controller public IPv4 addresses
 resource "azurerm_public_ip" "controllers" {
   count               = "${var.controller_count}"

azure/container-linux/kubernetes/require.tf

@@ -5,7 +5,7 @@ terraform {
 }
 
 provider "azurerm" {
-  version = "~> 1.16"
+  version = "~> 1.17"
 }
 
 provider "local" {