From 0310e846423a657d866b4c130482532437108736 Mon Sep 17 00:00:00 2001
From: magodo <wztdyl@sina.com>
Date: Fri, 5 Feb 2021 15:06:20 +0800
Subject: [PATCH] azurerm_lb_backend_address_pool: mark `backend_address` as
 computed (#10481)

Fix the regression caused by #10291, that the associated NIC will be cleared by LB BAP
---
 .../backend_address_pool_resource.go          |  3 +
 ...ncer_backend_address_pool_resource_test.go | 72 ++++++++++++++++++-
 2 files changed, 73 insertions(+), 2 deletions(-)

diff --git a/azurerm/internal/services/loadbalancer/backend_address_pool_resource.go b/azurerm/internal/services/loadbalancer/backend_address_pool_resource.go
index e8868ed484b5..7821e636879c 100644
--- a/azurerm/internal/services/loadbalancer/backend_address_pool_resource.go
+++ b/azurerm/internal/services/loadbalancer/backend_address_pool_resource.go
@@ -64,6 +64,9 @@ func resourceArmLoadBalancerBackendAddressPool() *schema.Resource {
 			"backend_address": {
 				Type:     schema.TypeSet,
 				Optional: true,
+				// Making this block optional for standard sku LB associating NIC, where the `name` will be computed after
+				// NIC associates with LB BAP by azurerm_network_interface_backend_address_pool_association.
+				Computed: true,
 				MinItems: 1,
 				Elem: &schema.Resource{
 					Schema: map[string]*schema.Schema{
diff --git a/azurerm/internal/services/loadbalancer/loadbalancer_backend_address_pool_resource_test.go b/azurerm/internal/services/loadbalancer/loadbalancer_backend_address_pool_resource_test.go
index 27cfb852e9aa..6fa594e8071f 100644
--- a/azurerm/internal/services/loadbalancer/loadbalancer_backend_address_pool_resource_test.go
+++ b/azurerm/internal/services/loadbalancer/loadbalancer_backend_address_pool_resource_test.go
@@ -275,11 +275,79 @@ func (r LoadBalancerBackendAddressPool) standardSkuNIC(data acceptance.TestData)
 	return fmt.Sprintf(`
 %s
 
+resource "azurerm_virtual_network" "test" {
+  name                = "testvnet-%[2]d"
+  location            = azurerm_resource_group.test.location
+  resource_group_name = azurerm_resource_group.test.name
+  address_space       = ["192.168.0.0/16"]
+}
+
+resource "azurerm_subnet" "test" {
+  name                 = "testsubnet-%[2]d"
+  resource_group_name  = azurerm_resource_group.test.name
+  virtual_network_name = azurerm_virtual_network.test.name
+  address_prefixes     = ["192.168.0.0/24"]
+}
+
+resource "azurerm_network_interface" "test" {
+  name                = "testnic-%[2]d"
+  location            = azurerm_resource_group.test.location
+  resource_group_name = azurerm_resource_group.test.name
+
+  ip_configuration {
+    name                          = "testconfiguration1"
+    subnet_id                     = azurerm_subnet.test.id
+    private_ip_address_allocation = "Dynamic"
+  }
+}
+
+resource "azurerm_linux_virtual_machine_scale_set" "test" {
+  name                = "acctestvmss-%[2]d"
+  resource_group_name = azurerm_resource_group.test.name
+  location            = azurerm_resource_group.test.location
+  sku                 = "Standard_F2"
+  instances           = 1
+  admin_username      = "adminuser"
+  admin_password      = "P@ssword1234!"
+
+  disable_password_authentication = false
+
+  source_image_reference {
+    publisher = "Canonical"
+    offer     = "UbuntuServer"
+    sku       = "16.04-LTS"
+    version   = "latest"
+  }
+
+  os_disk {
+    storage_account_type = "Standard_LRS"
+    caching              = "ReadWrite"
+  }
+
+  network_interface {
+    name    = "example"
+    primary = true
+
+    ip_configuration {
+      name                                   = "internal"
+      primary                                = true
+      subnet_id                              = azurerm_subnet.test.id
+      load_balancer_backend_address_pool_ids = [azurerm_lb_backend_address_pool.test.id]
+    }
+  }
+}
+
+resource "azurerm_network_interface_backend_address_pool_association" "test" {
+  ip_configuration_name   = "testconfiguration1"
+  network_interface_id    = azurerm_network_interface.test.id
+  backend_address_pool_id = azurerm_lb_backend_address_pool.test.id
+}
+
 resource "azurerm_lb_backend_address_pool" "test" {
   loadbalancer_id = azurerm_lb.test.id
-  name            = "Address-pool-%d"
+  name            = "Address-pool-%[2]d"
 }
-`, template, data.RandomInteger)
+`, template, data.RandomIntOfLength(8))
 }
 
 func (r LoadBalancerBackendAddressPool) standardSkuIPBasic(data acceptance.TestData) string {