diff --git a/cmd/check-gke-ingress/app/ingress/rule.go b/cmd/check-gke-ingress/app/ingress/rule.go
index 348137fa72..8377e56ffc 100644
--- a/cmd/check-gke-ingress/app/ingress/rule.go
+++ b/cmd/check-gke-ingress/app/ingress/rule.go
@@ -22,6 +22,7 @@ import (
 	"fmt"
 
 	corev1 "k8s.io/api/core/v1"
+	networkingv1 "k8s.io/api/networking/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	clientset "k8s.io/client-go/kubernetes"
@@ -33,6 +34,7 @@ import (
 	feconfigclient "k8s.io/ingress-gce/pkg/frontendconfig/client/clientset/versioned"
 )
 
+// CheckServiceExistence checks whether a service exists.
 func CheckServiceExistence(namespace, name string, client clientset.Interface) (*corev1.Service, string, string) {
 	svc, err := client.CoreV1().Services(namespace).Get(context.TODO(), name, metav1.GetOptions{})
 	if err != nil {
@@ -44,6 +46,11 @@ func CheckServiceExistence(namespace, name string, client clientset.Interface) (
 	return svc, report.Passed, fmt.Sprintf("Service %s/%s found", namespace, name)
 }
 
+// CheckBackendConfigAnnotation checks the BackendConfig annotation of a
+// service for:
+//
+//	whether the annotation is a valid BackendConfig json object.
+//	whether the annotation has `default` or `ports` field.
 func CheckBackendConfigAnnotation(svc *corev1.Service) (*annotations.BackendConfigs, string, string) {
 	val, ok := getBackendConfigAnnotation(svc)
 	if !ok {
@@ -59,6 +66,7 @@ func CheckBackendConfigAnnotation(svc *corev1.Service) (*annotations.BackendConf
 	return beConfigs, report.Passed, fmt.Sprintf("BackendConfig annotation is valid in service %s/%s", svc.Namespace, svc.Name)
 }
 
+// CheckBackendConfigExistence checks whether a BackendConfig exists.
 func CheckBackendConfigExistence(ns string, beConfigName string, svcName string, client beconfigclient.Interface) (*beconfigv1.BackendConfig, string, string) {
 	beConfig, err := client.CloudV1().BackendConfigs(ns).Get(context.TODO(), beConfigName, metav1.GetOptions{})
 	if err != nil {
@@ -70,6 +78,8 @@ func CheckBackendConfigExistence(ns string, beConfigName string, svcName string,
 	return beConfig, report.Passed, fmt.Sprintf("BackendConfig %s/%s in service %s/%s found", ns, beConfigName, ns, svcName)
 }
 
+// CheckHealthCheckTimeout checks whether timeout time is smaller than check
+// interval in backendconfig health check configuration.
 func CheckHealthCheckTimeout(beConfig *beconfigv1.BackendConfig, svcName string) (string, string) {
 	if beConfig.Spec.HealthCheck == nil {
 		return report.Skipped, fmt.Sprintf("BackendConfig %s/%s in service %s/%s  does not have healthcheck specified", beConfig.Namespace, beConfig.Name, beConfig.Namespace, svcName)
@@ -83,6 +93,14 @@ func CheckHealthCheckTimeout(beConfig *beconfigv1.BackendConfig, svcName string)
 	return report.Passed, fmt.Sprintf("BackendConfig %s/%s in service %s/%s healthcheck configuration is valid", beConfig.Namespace, beConfig.Name, beConfig.Namespace, svcName)
 }
 
+// CheckIngressRule checks whether an ingress rule has the http field.
+func CheckIngressRule(ingressRule *networkingv1.IngressRule) (*networkingv1.HTTPIngressRuleValue, string, string) {
+	if ingressRule.HTTP == nil {
+		return nil, report.Failed, "IngressRule has no field `http`"
+	}
+	return ingressRule.HTTP, report.Passed, "IngressRule has field `http`"
+}
+
 // CheckFrontendConfigExistence checks whether a FrontendConfig exists.
 func CheckFrontendConfigExistence(namespace, name string, client feconfigclient.Interface) (*feconfigv1beta1.FrontendConfig, string, string) {
 	feConfig, err := client.NetworkingV1beta1().FrontendConfigs(namespace).Get(context.TODO(), name, metav1.GetOptions{})
diff --git a/cmd/check-gke-ingress/app/ingress/rule_test.go b/cmd/check-gke-ingress/app/ingress/rule_test.go
index a7e26c5c54..54c9620e21 100644
--- a/cmd/check-gke-ingress/app/ingress/rule_test.go
+++ b/cmd/check-gke-ingress/app/ingress/rule_test.go
@@ -22,6 +22,7 @@ import (
 
 	"github.com/google/go-cmp/cmp"
 	corev1 "k8s.io/api/core/v1"
+	networkingv1 "k8s.io/api/networking/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	"k8s.io/client-go/kubernetes/fake"
@@ -312,3 +313,40 @@ func TestCheckFrontendConfigExistence(t *testing.T) {
 		}
 	}
 }
+
+func TestCheckIngressRule(t *testing.T) {
+
+	for _, tc := range []struct {
+		desc        string
+		ingressRule networkingv1.IngressRule
+		expect      string
+	}{
+		{
+			desc: "Ingress rule with http field",
+			ingressRule: networkingv1.IngressRule{
+				IngressRuleValue: networkingv1.IngressRuleValue{
+					HTTP: &networkingv1.HTTPIngressRuleValue{
+						Paths: []networkingv1.HTTPIngressPath{
+							{
+								Path: "/*",
+							},
+						},
+					},
+				},
+			},
+			expect: report.Passed,
+		},
+		{
+			desc: "Ingress rule without http field",
+			ingressRule: networkingv1.IngressRule{
+				IngressRuleValue: networkingv1.IngressRuleValue{},
+			},
+			expect: report.Failed,
+		},
+	} {
+		_, res, _ := CheckIngressRule(&tc.ingressRule)
+		if diff := cmp.Diff(tc.expect, res); diff != "" {
+			t.Errorf("For test case %s,  (-want +got):\n%s", tc.desc, diff)
+		}
+	}
+}