Allow updating google_container_cluster.monitoring_service (#598)

google/resource_container_cluster.go

@@ -173,7 +173,6 @@ func resourceContainerCluster() *schema.Resource {
 				Type:     schema.TypeString,
 				Optional: true,
 				Computed: true,
-				ForceNew: true,
 			},
 
 			"network": {
@@ -647,6 +646,31 @@ func resourceContainerClusterUpdate(d *schema.ResourceData, meta interface{}) er
 		d.SetPartial("enable_legacy_abac")
 	}
 
+	if d.HasChange("monitoring_service") {
+		desiredMonitoringService := d.Get("monitoring_service").(string)
+
+		req := &container.UpdateClusterRequest{
+			Update: &container.ClusterUpdate{
+				DesiredMonitoringService: desiredMonitoringService,
+			},
+		}
+		op, err := config.clientContainer.Projects.Zones.Clusters.Update(
+			project, zoneName, clusterName, req).Do()
+		if err != nil {
+			return err
+		}
+
+		// Wait until it's updated
+		waitErr := containerOperationWait(config, op, project, zoneName, "updating GKE cluster monitoring service", timeoutInMinutes, 2)
+		if waitErr != nil {
+			return waitErr
+		}
+		log.Printf("[INFO] Monitoring service for GKE cluster %s has been updated to %s", d.Id(),
+			desiredMonitoringService)
+
+		d.SetPartial("monitoring_service")
+	}
+
 	if n, ok := d.GetOk("node_pool.#"); ok {
 		for i := 0; i < n.(int); i++ {
 			if err := nodePoolUpdate(d, meta, clusterName, fmt.Sprintf("node_pool.%d.", i), timeoutInMinutes); err != nil {

google/resource_container_cluster_test.go

@@ -306,6 +306,36 @@ func TestAccContainerCluster_withLogging(t *testing.T) {
 	})
 }
 
+func TestAccContainerCluster_withMonitoring(t *testing.T) {
+	t.Parallel()
+
+	clusterName := fmt.Sprintf("cluster-test-%s", acctest.RandString(10))
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testAccCheckContainerClusterDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccContainerCluster_withMonitoring(clusterName),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckContainerCluster(
+						"google_container_cluster.with_monitoring"),
+					resource.TestCheckResourceAttr("google_container_cluster.with_monitoring", "monitoring_service", "monitoring.googleapis.com"),
+				),
+			},
+			{
+				Config: testAccContainerCluster_updateMonitoring(clusterName),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckContainerCluster(
+						"google_container_cluster.with_monitoring"),
+					resource.TestCheckResourceAttr("google_container_cluster.with_monitoring", "monitoring_service", "none"),
+				),
+			},
+		},
+	})
+}
+
 func TestAccContainerCluster_withNodePoolBasic(t *testing.T) {
 	t.Parallel()
 
@@ -1065,6 +1095,28 @@ resource "google_container_cluster" "with_logging" {
 }`, clusterName)
 }
 
+func testAccContainerCluster_withMonitoring(clusterName string) string {
+	return fmt.Sprintf(`
+resource "google_container_cluster" "with_monitoring" {
+	name               = "cluster-test-%s"
+	zone               = "us-central1-a"
+	initial_node_count = 1
+
+	monitoring_service = "monitoring.googleapis.com"
+}`, clusterName)
+}
+
+func testAccContainerCluster_updateMonitoring(clusterName string) string {
+	return fmt.Sprintf(`
+resource "google_container_cluster" "with_monitoring" {
+	name               = "cluster-test-%s"
+	zone               = "us-central1-a"
+	initial_node_count = 1
+
+	monitoring_service = "none"
+}`, clusterName)
+}
+
 func testAccContainerCluster_withNodePoolBasic(cluster, nodePool string) string {
 	return fmt.Sprintf(`
 resource "google_container_cluster" "with_node_pool" {