[#11433] Update google_compute_instance description in place (#9748) (#16900)

[upstream:ce85734ca809d9b8769df5456854ea8f6b680468]

Signed-off-by: Modular Magician <[email protected]>

Author: modular-magician

.changelog/9748.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+compute: allow users to update `google_compute_instance` `description` without recreating VMs
+```

google/services/compute/resource_compute_instance.go

@@ -562,7 +562,6 @@ func ResourceComputeInstance() *schema.Resource {
 			"description": {
 				Type:        schema.TypeString,
 				Optional:    true,
-				ForceNew:    true,
 				Description: `A brief description of the resource.`,
 			},
 
@@ -1613,6 +1612,35 @@ func resourceComputeInstanceUpdate(d *schema.ResourceData, meta interface{}) err
 	// Enable partial mode for the resource since it is possible
 	d.Partial(true)
 
+	if d.HasChange("description") {
+		err = transport_tpg.Retry(transport_tpg.RetryOptions{
+			RetryFunc: func() error {
+				instance, err := config.NewComputeClient(userAgent).Instances.Get(project, zone, instance.Name).Do()
+				if err != nil {
+					return fmt.Errorf("Error retrieving instance: %s", err)
+				}
+
+				instance.Description = d.Get("description").(string)
+
+				op, err := config.NewComputeClient(userAgent).Instances.Update(project, zone, instance.Name, instance).Do()
+				if err != nil {
+					return fmt.Errorf("Error updating instance: %s", err)
+				}
+
+				opErr := ComputeOperationWaitTime(config, op, project, "description, updating", userAgent, d.Timeout(schema.TimeoutUpdate))
+				if opErr != nil {
+					return opErr
+				}
+
+				return nil
+			},
+		})
+
+		if err != nil {
+			return err
+		}
+	}
+
 	if d.HasChange("metadata") {
 		metadata, err := resourceInstanceMetadata(d)
 		if err != nil {

google/services/compute/resource_compute_instance_test.go

@@ -267,6 +267,37 @@ func TestAccComputeInstance_resourceManagerTags(t *testing.T) {
 	})
 }
 
+func TestAccComputeInstance_descriptionUpdate(t *testing.T) {
+	t.Parallel()
+
+	var instance compute.Instance
+	var instanceName = fmt.Sprintf("tf-test-%s", acctest.RandString(t, 10))
+
+	acctest.VcrTest(t, resource.TestCase{
+		PreCheck:                 func() { acctest.AccTestPreCheck(t) },
+		ProtoV5ProviderFactories: acctest.ProtoV5ProviderFactories(t),
+		CheckDestroy:             testAccCheckComputeInstanceDestroyProducer(t),
+		Steps: []resource.TestStep{
+			{
+				Config: testAccComputeInstance_description(instanceName),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckComputeInstanceExists(
+						t, "google_compute_instance.foobar", &instance),
+					resource.TestCheckResourceAttr("google_compute_instance.foobar", "description", "old_desc"),
+				),
+			},
+			{
+				Config: testAccComputeInstance_descriptionUpdate(instanceName),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckComputeInstanceExists(
+						t, "google_compute_instance.foobar", &instance),
+					resource.TestCheckResourceAttr("google_compute_instance.foobar", "description", "new_desc"),
+				),
+			},
+		},
+	})
+}
+
 func TestAccComputeInstance_IP(t *testing.T) {
 	t.Parallel()
 
@@ -3466,6 +3497,58 @@ resource "google_compute_instance" "foobar" {
 `, instance)
 }
 
+func testAccComputeInstance_description(instance string) string {
+	return fmt.Sprintf(`
+data "google_compute_image" "my_image" {
+  family  = "debian-11"
+  project = "debian-cloud"
+}
+
+resource "google_compute_instance" "foobar" {
+  name         = "%s"
+  machine_type = "e2-medium"
+  zone         = "us-central1-a"
+  description  = "old_desc"
+
+  boot_disk {
+    initialize_params {
+      image = data.google_compute_image.my_image.self_link
+    }
+  }
+
+  network_interface {
+    network = "default"
+  }
+}
+`, instance)
+}
+
+func testAccComputeInstance_descriptionUpdate(instance string) string {
+	return fmt.Sprintf(`
+data "google_compute_image" "my_image" {
+  family  = "debian-11"
+  project = "debian-cloud"
+}
+
+resource "google_compute_instance" "foobar" {
+  name         = "%s"
+  machine_type = "e2-medium"
+  zone         = "us-central1-a"
+  description  = "new_desc"
+
+  boot_disk {
+    initialize_params {
+      image = data.google_compute_image.my_image.self_link
+    }
+  }
+
+  network_interface {
+    network = "default"
+  }
+}
+`, instance)
+}
+
 func testAccComputeInstance_resourceManagerTags(context map[string]interface{}) string {
 	return acctest.Nprintf(`
 resource "google_tags_tag_key" "key" {