0.12 Computed+Optional Attr syntax fixes (#3452)

<!-- This change is generated by MagicModules. -->
Original Author: @rileykarson

google/node_config.go

@@ -48,6 +48,9 @@ var schemaNodeConfig = &schema.Schema{
 				Optional: true,
 				Computed: true,
 				ForceNew: true,
+				// Legacy config mode allows removing GPU's from an existing resource
+				// See https://www.terraform.io/docs/configuration/attr-as-blocks.html
+				ConfigMode: schema.SchemaConfigModeAttr,
 				Elem: &schema.Resource{
 					Schema: map[string]*schema.Schema{
 						"count": {

google/resource_compute_instance_from_template_test.go

@@ -159,7 +159,6 @@ func TestAccComputeInstanceFromTemplate_012_removableFields(t *testing.T) {
 					testAccCheckComputeInstanceExists(resourceName, &instance),
 
 					// Check that fields were able to be removed
-					resource.TestCheckResourceAttr(resourceName, "service_account.#", "0"),
 					resource.TestCheckResourceAttr(resourceName, "scratch_disk.#", "0"),
 					resource.TestCheckResourceAttr(resourceName, "attached_disk.#", "0"),
 					resource.TestCheckResourceAttr(resourceName, "network_interface.0.alias_ip_range.#", "0"),

google/resource_container_node_pool_test.go

@@ -430,6 +430,39 @@ func TestAccContainerNodePool_regionalClusters(t *testing.T) {
 	})
 }
 
+func TestAccContainerNodePool_012_ConfigModeAttr(t *testing.T) {
+	t.Parallel()
+
+	cluster := fmt.Sprintf("tf-nodepool-test-%s", acctest.RandString(10))
+	np := fmt.Sprintf("tf-nodepool-test-%s", acctest.RandString(10))
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testAccCheckContainerNodePoolDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccContainerNodePool_012_ConfigModeAttr1(cluster, np),
+			},
+			{
+				ResourceName:            "google_container_node_pool.np",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"max_pods_per_node"},
+			},
+			{
+				Config: testAccContainerNodePool_012_ConfigModeAttr2(cluster, np),
+			},
+			{
+				ResourceName:            "google_container_node_pool.np",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"max_pods_per_node"},
+			},
+		},
+	})
+}
+
 func testAccCheckContainerNodePoolDestroy(s *terraform.State) error {
 	config := testAccProvider.Meta().(*Config)
 
@@ -824,3 +857,46 @@ resource "google_container_node_pool" "np" {
 	version = "${data.google_container_engine_versions.central1a.valid_node_versions.0}"
 }`, cluster, np)
 }
+
+func testAccContainerNodePool_012_ConfigModeAttr1(cluster, np string) string {
+	return fmt.Sprintf(`
+resource "google_container_cluster" "cluster" {
+	name               = "%s"
+	zone = "us-central1-f"
+	initial_node_count = 3
+}
+
+resource "google_container_node_pool" "np" {
+	name               = "%s"
+	zone = "us-central1-f"
+	cluster            = "${google_container_cluster.cluster.name}"
+	initial_node_count = 1
+
+	node_config {
+		guest_accelerator {
+			count = 1
+			type  = "nvidia-tesla-p100"
+		}
+	}
+}`, cluster, np)
+}
+
+func testAccContainerNodePool_012_ConfigModeAttr2(cluster, np string) string {
+	return fmt.Sprintf(`
+resource "google_container_cluster" "cluster" {
+	name               = "%s"
+	zone               = "us-central1-f"
+	initial_node_count = 3
+}
+
+resource "google_container_node_pool" "np" {
+	name               = "%s"
+	zone               = "us-central1-f"
+	cluster            = "${google_container_cluster.cluster.name}"
+	initial_node_count = 1
+
+	node_config {
+		guest_accelerator = []
+	}
+}`, cluster, np)
+}

website/docs/r/container_cluster.html.markdown

@@ -472,6 +472,8 @@ The `node_config` block supports:
 
 * `guest_accelerator` - (Optional) List of the type and count of accelerator cards attached to the instance.
     Structure documented below.
+    To support removal of guest_accelerators in Terraform 0.12 this field is an
+    [Attribute as Block](/docs/configuration/attr-as-blocks.html)
 
 * `image_type` - (Optional) The image type to use for this node. Note that changing the image type
     will delete and recreate all nodes in the node pool.