Add support for no-downtime disk resizes.

internal/features/defaults.go

@@ -27,6 +27,9 @@ func Default() UserFeatures {
 		LogAnalyticsWorkspace: LogAnalyticsWorkspaceFeatures{
 			PermanentlyDeleteOnDestroy: true,
 		},
+		ManagedDisk: ManagedDiskFeatures{
+			NoDowntimeResize: true,
+		},
 		ResourceGroup: ResourceGroupFeatures{
 			PreventDeletionIfContainsResources: true,
 		},

internal/features/user_flags.go

@@ -10,6 +10,7 @@ type UserFeatures struct {
 	TemplateDeployment     TemplateDeploymentFeatures
 	LogAnalyticsWorkspace  LogAnalyticsWorkspaceFeatures
 	ResourceGroup          ResourceGroupFeatures
+	ManagedDisk            ManagedDiskFeatures
 }
 
 type CognitiveAccountFeatures struct {
@@ -60,3 +61,7 @@ type ApiManagementFeatures struct {
 type ApplicationInsightFeatures struct {
 	DisableGeneratedRule bool
 }
+
+type ManagedDiskFeatures struct {
+	NoDowntimeResize bool
+}

internal/provider/features.go

@@ -243,6 +243,21 @@ func schemaFeatures(supportLegacyTestSuite bool) *pluginsdk.Schema {
 				},
 			},
 		},
+
+		"managed_disk": {
+			Type:     pluginsdk.TypeList,
+			Optional: true,
+			MaxItems: 1,
+			Elem: &pluginsdk.Resource{
+				Schema: map[string]*pluginsdk.Schema{
+					"no_downtime_resize": {
+						Type:     pluginsdk.TypeBool,
+						Optional: true,
+						Default:  true,
+					},
+				},
+			},
+		},
 	}
 
 	// this is a temporary hack to enable us to gradually add provider blocks to test configurations
@@ -407,5 +422,15 @@ func expandFeatures(input []interface{}) features.UserFeatures {
 		}
 	}
 
+	if raw, ok := val["managed_disk"]; ok {
+		items := raw.([]interface{})
+		if len(items) > 0 {
+			managedDiskRaw := items[0].(map[string]interface{})
+			if v, ok := managedDiskRaw["no_downtime_resize"]; ok {
+				featuresMap.ManagedDisk.NoDowntimeResize = v.(bool)
+			}
+		}
+	}
+
 	return featuresMap
 }

internal/provider/features_test.go

@@ -42,6 +42,9 @@ func TestExpandFeatures(t *testing.T) {
 				LogAnalyticsWorkspace: features.LogAnalyticsWorkspaceFeatures{
 					PermanentlyDeleteOnDestroy: true,
 				},
+				ManagedDisk: features.ManagedDiskFeatures{
+					NoDowntimeResize: true,
+				},
 				TemplateDeployment: features.TemplateDeploymentFeatures{
 					DeleteNestedItemsDuringDeletion: true,
 				},
@@ -98,6 +101,11 @@ func TestExpandFeatures(t *testing.T) {
 							"permanently_delete_on_destroy": true,
 						},
 					},
+					"managed_disk": []interface{}{
+						map[string]interface{}{
+							"no_downtime_resize": true,
+						},
+					},
 					"network": []interface{}{
 						map[string]interface{}{
 							"relaxed_locking": true,
@@ -154,6 +162,9 @@ func TestExpandFeatures(t *testing.T) {
 				LogAnalyticsWorkspace: features.LogAnalyticsWorkspaceFeatures{
 					PermanentlyDeleteOnDestroy: true,
 				},
+				ManagedDisk: features.ManagedDiskFeatures{
+					NoDowntimeResize: true,
+				},
 				ResourceGroup: features.ResourceGroupFeatures{
 					PreventDeletionIfContainsResources: true,
 				},
@@ -210,6 +221,11 @@ func TestExpandFeatures(t *testing.T) {
 							"permanently_delete_on_destroy": false,
 						},
 					},
+					"managed_disk": []interface{}{
+						map[string]interface{}{
+							"no_downtime_resize": false,
+						},
+					},
 					"network_locking": []interface{}{
 						map[string]interface{}{
 							"relaxed_locking": false,
@@ -266,6 +282,9 @@ func TestExpandFeatures(t *testing.T) {
 				LogAnalyticsWorkspace: features.LogAnalyticsWorkspaceFeatures{
 					PermanentlyDeleteOnDestroy: false,
 				},
+				ManagedDisk: features.ManagedDiskFeatures{
+					NoDowntimeResize: false,
+				},
 				ResourceGroup: features.ResourceGroupFeatures{
 					PreventDeletionIfContainsResources: false,
 				},
@@ -1025,3 +1044,68 @@ func TestExpandFeaturesResourceGroup(t *testing.T) {
 		}
 	}
 }
+
+func TestExpandFeaturesManagedDisk(t *testing.T) {
+	testData := []struct {
+		Name     string
+		Input    []interface{}
+		EnvVars  map[string]interface{}
+		Expected features.UserFeatures
+	}{
+		{
+			Name: "Empty Block",
+			Input: []interface{}{
+				map[string]interface{}{
+					"managed_disk": []interface{}{},
+				},
+			},
+			Expected: features.UserFeatures{
+				ManagedDisk: features.ManagedDiskFeatures{
+					NoDowntimeResize: true,
+				},
+			},
+		},
+		{
+			Name: "No Downtime Resize Enabled",
+			Input: []interface{}{
+				map[string]interface{}{
+					"managed_disk": []interface{}{
+						map[string]interface{}{
+							"no_downtime_resize": true,
+						},
+					},
+				},
+			},
+			Expected: features.UserFeatures{
+				ManagedDisk: features.ManagedDiskFeatures{
+					NoDowntimeResize: true,
+				},
+			},
+		},
+		{
+			Name: "No Downtime Resize Disabled",
+			Input: []interface{}{
+				map[string]interface{}{
+					"managed_disk": []interface{}{
+						map[string]interface{}{
+							"no_downtime_resize": false,
+						},
+					},
+				},
+			},
+			Expected: features.UserFeatures{
+				ManagedDisk: features.ManagedDiskFeatures{
+					NoDowntimeResize: false,
+				},
+			},
+		},
+	}
+
+	for _, testCase := range testData {
+		t.Logf("[DEBUG] Test Case: %q", testCase.Name)
+		result := expandFeatures(testCase.Input)
+		if !reflect.DeepEqual(result.ManagedDisk, testCase.Expected.ManagedDisk) {
+			t.Fatalf("Expected %+v but got %+v", result.ManagedDisk, testCase.Expected.ManagedDisk)
+		}
+	}
+}

internal/services/compute/managed_disk_resource.go

@@ -673,7 +673,9 @@ func resourceManagedDiskUpdate(d *pluginsdk.ResourceData, meta interface{}) erro
 
 	if d.HasChange("disk_size_gb") {
 		if old, new := d.GetChange("disk_size_gb"); new.(int) > old.(int) {
-			shouldShutDown = true
+			if !meta.(*clients.Client).Features.ManagedDisk.NoDowntimeResize || shutDownOnResize(disk, old.(int), new.(int)) {
+				shouldShutDown = true
+			}
 			diskUpdate.Properties.DiskSizeGB = utils.Int64(int64(new.(int)))
 		} else {
 			return fmt.Errorf("- New size must be greater than original size. Shrinking disks is not supported on Azure")
@@ -1000,3 +1002,27 @@ func resourceManagedDiskDelete(d *pluginsdk.ResourceData, meta interface{}) erro
 
 	return nil
 }
+
+// shutDownOnResize implements live resize restrictions according to https://docs.microsoft.com/en-us/azure/virtual-machines/linux/expand-disks#expand-without-downtime
+func shutDownOnResize(disk compute.Disk, oldSizeGB, newSizeGB int) bool {
+	// OS disks can't be expanded without downtime.
+	if disk.OsType != "" {
+		return true
+	}
+	// Disks smaller than 4 TiB can't be expanded to 4 TiB or larger without downtime.
+	if oldSizeGB < 4096 && newSizeGB >= 4096 {
+		return true
+	}
+	// Only  Premium SSD v1 and Standard SSD disks support live resize
+	for _, diskType := range []compute.DiskStorageAccountTypes{
+		compute.DiskStorageAccountTypesPremiumLRS,
+		compute.DiskStorageAccountTypesPremiumZRS,
+		compute.DiskStorageAccountTypesStandardSSDLRS,
+		compute.DiskStorageAccountTypesStandardSSDZRS,
+	} {
+		if disk.Sku.Name == diskType {
+			return false
+		}
+	}
+	return true
+}

website/docs/guides/features-block.html.markdown

@@ -49,6 +49,10 @@ provider "azurerm" {
       permanently_delete_on_destroy = true
     }
 
+    managed_disk {
+      no_downtime_resize = true
+    }
+
     resource_group {
       prevent_deletion_if_contains_resources = true
     }
@@ -86,6 +90,8 @@ The `features` block supports the following:
 
 * `log_analytics_workspace` - (Optional) A `log_analytics_workspace` block as defined below.
 
+* `managed_disk` - (Optional) A `managed_disk` block as defined below.
+
 * `resource_group` - (Optional) A `resource_group` block as defined below.
 
 * `template_deployment` - (Optional) A `template_deployment` block as defined below.
@@ -150,6 +156,12 @@ The `log_analytics_workspace` block supports the following:
 
 ---
 
+The `managed_disk` block supports the following:
+
+* `no_downtime_resize` (Optional) Specifies if no-downtime resizes are enabled for the managed disk resources. Defaults to `true`.
+
+---
+
 The `resource_group` block supports the following:
 
 * `prevent_deletion_if_contains_resources` - (Optional) Should the `azurerm_resource_group` resource check that there are no Resources within the Resource Group during deletion? This means that all Resources within the Resource Group must be deleted prior to deleting the Resource Group. Defaults to `true`.