workbench: Fix a bug with instance metadata being removed not working as expected

mmv1/templates/terraform/constants/workbench_instance.go.tmpl

@@ -243,23 +243,23 @@ func resizeWorkbenchInstanceDisk(config *transport_tpg.Config, d *schema.Resourc
 	return nil
 }
 
-// mergeLabels takes two maps of labels and returns a new map with the labels merged.
-// If a key exists in old_labels but not in new_labels, it is added to the new map with an empty value.
-func mergeLabels(oldLabels, newLabels map[string]interface{}) map[string]string {
-	modifiedLabels := make(map[string]string)
+// mergeMaps takes two maps and returns a new map with the merged results.
+// If a key exists in old_maps but not in new_maps, it is added to the new map with an empty value.
+func mergeMaps(oldMaps, newMaps map[string]interface{}) map[string]string {
+	modifiedMaps := make(map[string]string)
 
-	// Add all labels from newLabels to modifiedLabels
-	for k, v := range newLabels {
-		modifiedLabels[k] = v.(string)
+	// Add all maps from newMaps to modifiedMaps
+	for k, v := range newMaps {
+		modifiedMaps[k] = v.(string)
 	}
 
-	// Add any keys from oldLabels that are not in newLabels with an empty value
-	for k := range oldLabels {
-		if _, ok := newLabels[k]; !ok {
-			modifiedLabels[k] = ""
+	// Add any keys from oldMaps that are not in newMaps with an empty value
+	for k := range oldMaps {
+		if _, ok := newMaps[k]; !ok {
+			modifiedMaps[k] = ""
 		}
 	}
 
-	return modifiedLabels
+	return modifiedMaps
 }
-{{- end }}
+{{- end }}

mmv1/templates/terraform/pre_update/workbench_instance.go.tmpl

@@ -42,7 +42,14 @@ if d.HasChange("effective_labels") {
   old_labels_interface, new_labels_interface := d.GetChange("effective_labels")
   old_labels := old_labels_interface.(map[string]interface{})
   new_labels := new_labels_interface.(map[string]interface{})
-  obj["labels"] = mergeLabels(old_labels,new_labels)
+  obj["labels"] = mergeMaps(old_labels,new_labels)
+}
+
+if d.HasChange("gce_setup.0.metadata") {
+  old_metadata_interface, new_metadata_interface := d.GetChange("gce_setup.0.metadata")
+  old_metadata := old_metadata_interface.(map[string]interface{})
+  new_metadata := new_metadata_interface.(map[string]interface{})
+  obj["gceSetup"].(map[string]interface{})["metadata"] = mergeMaps(old_metadata,new_metadata)
 }
 
 name := d.Get("name").(string)

mmv1/third_party/terraform/services/workbench/resource_workbench_instance_test.go.tmpl

@@ -290,6 +290,73 @@ func TestAccWorkbenchInstance_updateMetadata(t *testing.T) {
 				Check: resource.ComposeTestCheckFunc(
                     	resource.TestCheckResourceAttr(
                         		"google_workbench_instance.instance", "state", "ACTIVE"),
+                ),
+			},
+			{
+				ResourceName:            "google_workbench_instance.instance",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"name", "instance_owners", "location", "instance_id", "request_id", "labels", "terraform_labels"},
+			},
+			{
+				Config: testAccWorkbenchInstance_basic(context),
+				Check: resource.ComposeTestCheckFunc(
+                    	resource.TestCheckResourceAttr(
+                        		"google_workbench_instance.instance", "state", "ACTIVE"),
+                ),
+			},
+			{
+				ResourceName:            "google_workbench_instance.instance",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"name", "instance_owners", "location", "instance_id", "request_id", "labels", "terraform_labels"},
+			},
+		},
+	})
+}
+
+func TestAccWorkbenchInstance_updateMetadataKey(t *testing.T) {
+	t.Parallel()
+
+	context := map[string]interface{}{
+		"random_suffix": acctest.RandString(t, 10),
+	}
+
+	acctest.VcrTest(t, resource.TestCase{
+		PreCheck:                 func() { acctest.AccTestPreCheck(t) },
+		ProtoV5ProviderFactories: acctest.ProtoV5ProviderFactories(t),
+		Steps: []resource.TestStep{
+			{
+				Config: testAccWorkbenchInstance_updateMetadata(context),
+				Check: resource.ComposeTestCheckFunc(
+                    	resource.TestCheckResourceAttr(
+                        		"google_workbench_instance.instance", "state", "ACTIVE"),
+                ),
+			},
+			{
+				ResourceName:            "google_workbench_instance.instance",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"name", "instance_owners", "location", "instance_id", "request_id", "labels", "terraform_labels"},
+			},
+      		{
+				Config: testAccWorkbenchInstance_updateMetadataKey(context),
+				Check: resource.ComposeTestCheckFunc(
+                    	resource.TestCheckResourceAttr(
+                        		"google_workbench_instance.instance", "state", "ACTIVE"),
+                ),
+			},
+			{
+				ResourceName:            "google_workbench_instance.instance",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"name", "instance_owners", "location", "instance_id", "request_id", "labels", "terraform_labels"},
+			},
+			{
+				Config: testAccWorkbenchInstance_updateMetadata(context),
+				Check: resource.ComposeTestCheckFunc(
+                    	resource.TestCheckResourceAttr(
+                        		"google_workbench_instance.instance", "state", "ACTIVE"),
                 ),
 			},
 			{
@@ -322,6 +389,27 @@ resource "google_workbench_instance" "instance" {
 `, context)
 }
 
+func testAccWorkbenchInstance_updateMetadataKey(context map[string]interface{}) string {
+	return acctest.Nprintf(`
+resource "google_workbench_instance" "instance" {
+  name = "tf-test-workbench-instance%{random_suffix}"
+  location = "us-central1-a"
+
+  gce_setup {
+    metadata = {
+      terraform = "true",
+	  "idle-timeout-seconds" = "10800",
+    }
+  }
+
+  labels = {
+    k = "val"
+  }
+
+}
+`, context)
+}
+
 func TestAccWorkbenchInstance_updateState(t *testing.T) {
 	t.Parallel()