wait subnet lb clear in set subnet EnableLb to false e2e (#2450)

test/e2e/kube-ovn/subnet/subnet.go

@@ -12,6 +12,7 @@ import (
 	"time"
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/wait"
 	clientset "k8s.io/client-go/kubernetes"
 	"k8s.io/kubernetes/test/e2e/framework/deployment"
 	e2enode "k8s.io/kubernetes/test/e2e/framework/node"
@@ -858,10 +859,21 @@ var _ = framework.Describe("[group:subnet]", func() {
 		modifiedSubnet := subnet.DeepCopy()
 		modifiedSubnet.Spec.EnableLb = &enbleLb
 		subnet = subnetClient.PatchSync(subnet, modifiedSubnet)
-		execCmd = "kubectl ko nbctl --format=csv --data=bare --no-heading --columns=load_balancer find logical-switch " + fmt.Sprintf("name=%s", subnetName)
-		output, err = exec.Command("bash", "-c", execCmd).CombinedOutput()
+		err = wait.PollImmediate(2*time.Second, 1*time.Minute, func() (bool, error) {
+			execCmd = "kubectl ko nbctl --format=csv --data=bare --no-heading --columns=load_balancer find logical-switch " + fmt.Sprintf("name=%s", subnetName)
+			output, err = exec.Command("bash", "-c", execCmd).CombinedOutput()
+			if err != nil {
+				return false, err
+			}
+			if strings.TrimSpace(string(output)) == "" {
+				return true, nil
+			}
+			return false, nil
+		})
+		if framework.IsTimeout(err) {
+			framework.Failf("timed out while wait lb record of subnet %s to clear ", subnet.Name)
+		}
 		framework.ExpectNoError(err)
-		framework.ExpectEmpty(strings.TrimSpace(string(output)))
 
 		ginkgo.By("Validating empty subnet spec enableLb field, should keep same value as args enableLb")
 		modifiedSubnet = subnet.DeepCopy()