Make GKE cluster enable_l4_ilb_subsetting a computed field (#15814)

Author: FelipeYepez

mmv1/third_party/terraform/services/container/resource_container_cluster.go.tmpl

@@ -2353,8 +2353,8 @@ func ResourceContainerCluster() *schema.Resource {
 			"enable_l4_ilb_subsetting": {
 			   Type: schema.TypeBool,
 			   Optional: true,
+			   Computed: true,
 			   Description: `Whether L4ILB Subsetting is enabled for this cluster.`,
-			   Default: false,
 			},
 			"disable_l4_lb_firewall_reconciliation": {
 				Type:        schema.TypeBool,

mmv1/third_party/terraform/services/container/resource_container_cluster_test.go.tmpl

@@ -621,6 +621,50 @@ func TestAccContainerCluster_withILBSubsetting(t *testing.T) {
 	})
 }
 
+func TestAccContainerCluster_omittedILBSubsetting(t *testing.T) {
+	t.Parallel()
+
+	clusterName := fmt.Sprintf("tf-test-cluster-%s", acctest.RandString(t, 10))
+	npName := fmt.Sprintf("tf-test-cluster-nodepool-%s", acctest.RandString(t, 10))
+	networkName := acctest.BootstrapSharedTestNetwork(t, "gke-cluster")
+	subnetworkName := acctest.BootstrapSubnet(t, "gke-cluster", networkName)
+
+	acctest.VcrTest(t, resource.TestCase{
+		PreCheck:                 func() { acctest.AccTestPreCheck(t) },
+		ProtoV5ProviderFactories: acctest.ProtoV5ProviderFactories(t),
+		CheckDestroy:             testAccCheckContainerClusterDestroyProducer(t),
+		Steps: []resource.TestStep{
+			{
+				Config: testAccContainerCluster_omittedILBSubSetting(clusterName, npName, networkName, subnetworkName),
+			},
+			{
+				ResourceName:            "google_container_cluster.confidential_nodes",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"deletion_protection"},
+			},
+			{
+				Config: testAccContainerCluster_withILBSubSetting(clusterName, npName, networkName, subnetworkName),
+			},
+			{
+				ResourceName:            "google_container_cluster.confidential_nodes",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"deletion_protection"},
+			},
+			{
+				Config: testAccContainerCluster_omittedILBSubSetting(clusterName, npName, networkName, subnetworkName),
+			},
+			{
+				ResourceName:            "google_container_cluster.confidential_nodes",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"deletion_protection"},
+			},
+		},
+	})
+}
+
 func TestAccContainerCluster_disableL4LbFirewallReconciliation(t *testing.T) {
 	t.Parallel()
 
@@ -7837,6 +7881,33 @@ resource "google_container_cluster" "confidential_nodes" {
 `, clusterName, npName, networkName, subnetworkName)
 }
 
+func testAccContainerCluster_omittedILBSubSetting(clusterName, npName, networkName, subnetworkName string) string {
+	return fmt.Sprintf(`
+resource "google_container_cluster" "confidential_nodes" {
+  name     = "%s"
+  location = "us-central1-a"
+  release_channel {
+    channel = "RAPID"
+  }
+
+  node_pool {
+    name               = "%s"
+    initial_node_count = 1
+    node_config {
+      machine_type = "e2-medium"
+    }
+  }
+
+  // enable_l4_ilb_subsetting omitted
+
+  network    = "%s"
+  subnetwork = "%s"
+
+  deletion_protection = false
+}
+`, clusterName, npName, networkName, subnetworkName)
+}
+
 func testAccContainerCluster_disableILBSubSetting(clusterName, npName, networkName, subnetworkName string) string {
 	return fmt.Sprintf(`
 resource "google_container_cluster" "confidential_nodes" {