allow master authorized networks config to be removed

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

Author: megan07

google/resource_container_cluster.go

@@ -1771,7 +1771,9 @@ func expandMasterAuth(configured interface{}) *containerBeta.MasterAuth {
 func expandMasterAuthorizedNetworksConfig(configured interface{}) *containerBeta.MasterAuthorizedNetworksConfig {
 	l := configured.([]interface{})
 	if len(l) == 0 {
-		return nil
+		return &containerBeta.MasterAuthorizedNetworksConfig{
+			Enabled: false,
+		}
 	}
 	result := &containerBeta.MasterAuthorizedNetworksConfig{
 		Enabled: true,
@@ -1990,7 +1992,7 @@ func flattenMasterAuth(ma *containerBeta.MasterAuth) []map[string]interface{} {
 }
 
 func flattenMasterAuthorizedNetworksConfig(c *containerBeta.MasterAuthorizedNetworksConfig) []map[string]interface{} {
-	if c == nil {
+	if c == nil || !c.Enabled {
 		return nil
 	}
 	result := make(map[string]interface{})

google/resource_container_cluster_test.go

@@ -390,6 +390,15 @@ func TestAccContainerCluster_withMasterAuthorizedNetworksConfig(t *testing.T) {
 				ImportState:         true,
 				ImportStateVerify:   true,
 			},
+			{
+				Config: testAccContainerCluster_removeMasterAuthorizedNetworksConfig(clusterName),
+			},
+			{
+				ResourceName:        "google_container_cluster.with_master_authorized_networks",
+				ImportStateIdPrefix: "us-central1-a/",
+				ImportState:         true,
+				ImportStateVerify:   true,
+			},
 		},
 	})
 }
@@ -1463,7 +1472,7 @@ func testAccContainerCluster_withMasterAuthorizedNetworksConfig(clusterName stri
 	return fmt.Sprintf(`
 resource "google_container_cluster" "with_master_authorized_networks" {
 	name = "%s"
-	zone = "us-central1-a"
+	location = "us-central1-a"
 	initial_node_count = 1
 
 	master_authorized_networks_config {
@@ -1472,6 +1481,16 @@ resource "google_container_cluster" "with_master_authorized_networks" {
 }`, clusterName, cidrBlocks)
 }
 
+func testAccContainerCluster_removeMasterAuthorizedNetworksConfig(clusterName string) string {
+
+	return fmt.Sprintf(`
+resource "google_container_cluster" "with_master_authorized_networks" {
+	name = "%s"
+	location = "us-central1-a"
+	initial_node_count = 1
+}`, clusterName)
+}
+
 func testAccContainerCluster_regional(clusterName string) string {
 	return fmt.Sprintf(`
 resource "google_container_cluster" "regional" {