Add comments for check-gke-ingress rules

cmd/check-gke-ingress/app/ingress/rule.go

@@ -34,6 +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 {
@@ -45,6 +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 {
@@ -60,6 +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 {
@@ -71,6 +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)
@@ -84,6 +93,7 @@ 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`"