azurerm_application_insights - re-add support for updating workspace_id

internal/services/applicationinsights/application_insights_resource.go

@@ -78,7 +78,6 @@ func resourceApplicationInsights() *pluginsdk.Resource {
 			"workspace_id": {
 				Type:         pluginsdk.TypeString,
 				Optional:     true,
-				ForceNew:     true,
 				ValidateFunc: workspaces.ValidateWorkspaceID,
 			},
 
@@ -227,6 +226,13 @@ func resourceApplicationInsightsCreateUpdate(d *pluginsdk.ResourceData, meta int
 		ForceCustomerStorageForProfiler: utils.Bool(forceCustomerStorageForProfiler),
 	}
 
+	if !d.IsNewResource() {
+		oldWorkspaceId, newWorkspaceId := d.GetChange("workspace_id")
+		if oldWorkspaceId.(string) != "" && newWorkspaceId.(string) == "" {
+			return fmt.Errorf("`workspace_id` can not be removed after set")
+		}
+	}
+
 	if workspaceRaw, hasWorkspaceId := d.GetOk("workspace_id"); hasWorkspaceId {
 		workspaceID, err := workspaces.ParseWorkspaceID(workspaceRaw.(string))
 		if err != nil {

internal/services/applicationinsights/application_insights_resource_test.go

@@ -152,10 +152,16 @@ func TestAccApplicationInsights_basicWorkspaceMode(t *testing.T) {
 
 	data.ResourceTest(t, r, []acceptance.TestStep{
 		{
-			Config: r.basic_workspace_mode(data),
+			Config: r.basicWorkspaceMode(data),
+			Check: acceptance.ComposeTestCheckFunc(
+				check.That(data.ResourceName).ExistsInAzure(r),
+			),
+		},
+		data.ImportStep(),
+		{
+			Config: r.basicWorkspaceModeUpdated(data),
 			Check: acceptance.ComposeTestCheckFunc(
 				check.That(data.ResourceName).ExistsInAzure(r),
-				check.That(data.ResourceName).Key("workspace_id").Exists(),
 			),
 		},
 		data.ImportStep(),
@@ -279,7 +285,7 @@ resource "azurerm_application_insights" "test" {
 `, data.RandomInteger, data.Locations.Primary, data.RandomInteger, applicationType)
 }
 
-func (AppInsightsResource) basic_workspace_mode(data acceptance.TestData) string {
+func (AppInsightsResource) basicWorkspaceMode(data acceptance.TestData) string {
 	return fmt.Sprintf(`
 provider "azurerm" {
   features {}
@@ -308,6 +314,43 @@ resource "azurerm_application_insights" "test" {
 `, data.RandomInteger, data.Locations.Primary, data.RandomInteger, data.RandomInteger)
 }
 
+func (AppInsightsResource) basicWorkspaceModeUpdated(data acceptance.TestData) string {
+	return fmt.Sprintf(`
+provider "azurerm" {
+  features {}
+}
+
+resource "azurerm_resource_group" "test" {
+  name     = "acctestRG-appinsights-%[2]d"
+  location = "%[1]s"
+}
+
+resource "azurerm_log_analytics_workspace" "test" {
+  name                = "acctest-%[2]d"
+  location            = azurerm_resource_group.test.location
+  resource_group_name = azurerm_resource_group.test.name
+  sku                 = "PerGB2018"
+  retention_in_days   = 30
+}
+
+resource "azurerm_log_analytics_workspace" "test2" {
+  name                = "acctest2-%[2]d"
+  location            = azurerm_resource_group.test.location
+  resource_group_name = azurerm_resource_group.test.name
+  sku                 = "PerGB2018"
+  retention_in_days   = 30
+}
+
+resource "azurerm_application_insights" "test" {
+  name                = "acctestappinsights-%[2]d"
+  location            = azurerm_resource_group.test.location
+  resource_group_name = azurerm_resource_group.test.name
+  workspace_id        = azurerm_log_analytics_workspace.test2.id
+  application_type    = "web"
+}
+`, data.Locations.Primary, data.RandomInteger)
+}
+
 func (AppInsightsResource) requiresImport(data acceptance.TestData, applicationType string) string {
 	template := AppInsightsResource{}.basic(data, applicationType)
 	return fmt.Sprintf(`

website/docs/r/application_insights.html.markdown

@@ -91,7 +91,9 @@ The following arguments are supported:
 
 * `tags` - (Optional) A mapping of tags to assign to the resource.
 
-* `workspace_id` - (Optional) Specifies the id of a log analytics workspace resource. Changing this forces a new resource to be created.
+* `workspace_id` - (Optional) Specifies the id of a log analytics workspace resource.
+
+~> **NOTE:** This can not be removed after set. More details can be found at [Migrate to workspace-based Application Insights resources](https://docs.microsoft.com/azure/azure-monitor/app/convert-classic-resource#migration-process)
 
 * `local_authentication_disabled` - (Optional) Disable Non-Azure AD based Auth. Defaults to `false`.