azurerm_kubernetes_cluster - min_count can be updated when enable_auto_scaling is set to true

azurerm/internal/services/containers/kubernetes_nodepool.go

@@ -260,7 +260,7 @@ func ExpandDefaultNodePool(d *schema.ResourceData) (*[]containerservice.ManagedC
 		if minCount > 0 {
 			profile.MinCount = utils.Int32(int32(minCount))
 
-			if minCount > count {
+			if minCount > count && d.IsNewResource() {
 				return nil, fmt.Errorf("`node_count`(%d) must be equal to or greater than `min_count`(%d) when `enable_auto_scaling` is set to `true`", count, minCount)
 			}
 		} else {

azurerm/internal/services/containers/tests/kubernetes_cluster_upgrade_test.go

@@ -10,6 +10,7 @@ import (
 )
 
 var kubernetesUpgradeTests = map[string]func(t *testing.T){
+	"UpgradeAutoScaleMinCount":                      testAccAzureRMKubernetesCluster_upgradeAutoScaleMinCount,
 	"upgradeControlPlane":                           testAccAzureRMKubernetesCluster_upgradeControlPlane,
 	"upgradeControlPlaneAndDefaultNodePoolTogether": testAccAzureRMKubernetesCluster_upgradeControlPlaneAndDefaultNodePoolTogether,
 	"upgradeControlPlaneAndDefaultNodePoolTwoPhase": testAccAzureRMKubernetesCluster_upgradeControlPlaneAndDefaultNodePoolTwoPhase,
@@ -18,6 +19,37 @@ var kubernetesUpgradeTests = map[string]func(t *testing.T){
 	"upgradeCustomNodePoolBeforeControlPlaneFails":  testAccAzureRMKubernetesCluster_upgradeCustomNodePoolBeforeControlPlaneFails,
 }
 
+func TestAccAzureRMKubernetesCluster_upgradeAutoScaleMinCount(t *testing.T) {
+	checkIfShouldRunTestsIndividually(t)
+	testAccAzureRMKubernetesCluster_upgradeAutoScaleMinCount(t)
+}
+
+func testAccAzureRMKubernetesCluster_upgradeAutoScaleMinCount(t *testing.T) {
+	data := acceptance.BuildTestData(t, "azurerm_kubernetes_cluster", "test")
+
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:     func() { acceptance.PreCheck(t) },
+		Providers:    acceptance.SupportedProviders,
+		CheckDestroy: testCheckAzureRMKubernetesClusterDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccAzureRMKubernetesCluster_upgradeAutoScaleMinCountConfig(data, olderKubernetesVersion, 3, 8),
+				Check: resource.ComposeTestCheckFunc(
+					testCheckAzureRMKubernetesClusterExists(data.ResourceName),
+				),
+			},
+			data.ImportStep(),
+			{
+				Config: testAccAzureRMKubernetesCluster_upgradeAutoScaleMinCountConfig(data, olderKubernetesVersion, 4, 8),
+				Check: resource.ComposeTestCheckFunc(
+					testCheckAzureRMKubernetesClusterExists(data.ResourceName),
+				),
+			},
+			data.ImportStep(),
+		},
+	})
+}
+
 func TestAccAzureRMKubernetesCluster_upgradeControlPlane(t *testing.T) {
 	checkIfShouldRunTestsIndividually(t)
 	testAccAzureRMKubernetesCluster_upgradeControlPlane(t)
@@ -326,3 +358,36 @@ resource "azurerm_kubernetes_cluster_node_pool" "test" {
 }
 `, template, customNodePoolVersion)
 }
+
+func testAccAzureRMKubernetesCluster_upgradeAutoScaleMinCountConfig(data acceptance.TestData, controlPlaneVersion string, minCount int, maxCount int) string {
+	return fmt.Sprintf(`
+provider "azurerm" {
+  features {}
+}
+
+resource "azurerm_resource_group" "test" {
+  name     = "acctestRG-aks-%d"
+  location = "%s"
+}
+
+resource "azurerm_kubernetes_cluster" "test" {
+  name                = "acctestaks%d"
+  location            = azurerm_resource_group.test.location
+  resource_group_name = azurerm_resource_group.test.name
+  dns_prefix          = "acctestaks%d"
+  kubernetes_version  = %q
+
+  default_node_pool {
+    name                = "default"
+    vm_size             = "Standard_DS2_v2"
+    enable_auto_scaling = true
+    min_count           = %d
+    max_count           = %d
+  }
+
+  identity {
+    type = "SystemAssigned"
+  }
+}
+`, data.RandomInteger, data.Locations.Primary, data.RandomInteger, data.RandomInteger, controlPlaneVersion, minCount, maxCount)
+}