azurerm_machine_learning_compute_cluster change subnet_resource_id co…

…nstraint: Respect Managed Vnet when creating compute clusters fixes #25901  (#26073)

* Respect ManagedVnet constraints when creating compute clusters

* Apply suggestions from code review

Co-authored-by: stephybun <steph@hashicorp.com>

* extend nil checks

* fix error statement

* add accidently removed ImportAsExistsErrore

* fix linting and test issues

---------

Co-authored-by: Hamade, Marcel  SF/HZA-ZC3P <hamadmrc@schaeffler.com>
Co-authored-by: stephybun <steph@hashicorp.com>

internal/services/machinelearning/machine_learning_compute_cluster_resource.go

@@ -173,21 +173,63 @@ func resourceComputeClusterCreate(d *pluginsdk.ResourceData, meta interface{}) e
 	if err != nil {
 		return err
 	}
-
+	// Get the Machine Learning Workspace...
 	id := machinelearningcomputes.NewComputeID(workspaceID.SubscriptionId, workspaceID.ResourceGroupName, workspaceID.WorkspaceName, d.Get("name").(string))
 
+	workspace, err := mlWorkspacesClient.Get(ctx, *workspaceID)
+	if err != nil {
+		return fmt.Errorf("retrieving %s: %+v", workspaceID, err)
+	}
+
+	workspaceModel := workspace.Model
+	if workspaceModel == nil {
+		return fmt.Errorf("retrieving %s: `model` was nil", workspaceID)
+	}
+
+	if workspaceModel.Sku == nil || workspaceModel.Sku.Tier == nil || workspaceModel.Sku.Name == "" {
+		return fmt.Errorf("retrieving %s: `sku` was nil or empty", workspaceID)
+	}
+
+	if workspaceModel.Location == nil {
+		return fmt.Errorf("retrieving %s: `location` was nil", workspaceID)
+	}
+
+	identity, err := expandIdentity(d.Get("identity").([]interface{}))
+	if err != nil {
+		return fmt.Errorf("expanding `identity`: %+v", err)
+	}
+
 	existing, err := client.ComputeGet(ctx, id)
 	if err != nil {
 		if !response.WasNotFound(existing.HttpResponse) {
 			return fmt.Errorf("checking for presence of existing %s: %+v", id, err)
 		}
 	}
+
 	if !response.WasNotFound(existing.HttpResponse) {
 		return tf.ImportAsExistsError("azurerm_machine_learning_compute_cluster", id.ID())
 	}
+	nodePublicIPEnabled, ok := d.Get("node_public_ip_enabled").(bool)
+	if !ok {
+		return fmt.Errorf("unable to assert type for `node_public_ip_enabled`")
+	}
 
-	if !d.Get("node_public_ip_enabled").(bool) && d.Get("subnet_resource_id").(string) == "" {
-		return fmt.Errorf("`subnet_resource_id` must be set if `node_public_ip_enabled` is set to `false`")
+	subnetResourceID, ok := d.Get("subnet_resource_id").(string)
+	if !ok {
+		return fmt.Errorf("unable to assert type for `subnet_resource_id`")
+	}
+
+	workspaceInManagedVnet := false
+
+	if workspaceModel.Properties != nil &&
+		workspaceModel.Properties.ManagedNetwork != nil &&
+		workspaceModel.Properties.ManagedNetwork.Status != nil &&
+		workspaceModel.Properties.ManagedNetwork.Status.Status != nil {
+		workspaceInManagedVnet = *workspaceModel.Properties.ManagedNetwork.Status.Status == workspaces.ManagedNetworkStatusActive
+	}
+
+	if !nodePublicIPEnabled && subnetResourceID == "" && !workspaceInManagedVnet {
+		return fmt.Errorf("`subnet_resource_id` must be set if `node_public_ip_enabled` is set to `false` or the workspace is not in a managed network")
 	}
 
 	vmPriority := machinelearningcomputes.VMPriority(d.Get("vm_priority").(string))
@@ -217,30 +259,6 @@ func resourceComputeClusterCreate(d *pluginsdk.ResourceData, meta interface{}) e
 		DisableLocalAuth: utils.Bool(!d.Get("local_auth_enabled").(bool)),
 	}
 
-	// Get the Machine Learning Workspace...
-	workspace, err := mlWorkspacesClient.Get(ctx, *workspaceID)
-	if err != nil {
-		return err
-	}
-
-	workspaceModel := workspace.Model
-	if workspaceModel == nil {
-		return fmt.Errorf("machine learning %s Workspace: model was nil", id)
-	}
-
-	if workspaceModel.Sku == nil || workspaceModel.Sku.Tier == nil || workspaceModel.Sku.Name == "" {
-		return fmt.Errorf("machine learning %s Workspace: `SKU` was nil or empty", id)
-	}
-
-	if workspaceModel.Location == nil {
-		return fmt.Errorf("machine learning %s Workspace: `Location` was nil", id)
-	}
-
-	identity, err := expandIdentity(d.Get("identity").([]interface{}))
-	if err != nil {
-		return fmt.Errorf("expanding `identity`: %+v", err)
-	}
-
 	// NOTE: The 'ComputeResource' 'Location' field should always point
 	// to the workspace's 'location'...
 	computeClusterParameters := machinelearningcomputes.ComputeResource{