[kdoctor-io#303]fix-Failed_to_get_the_dns_service_IP_list

pkg/agentDnsServer/appDnsServer.go

@@ -36,6 +36,12 @@ func SetupAppDnsServer(rootLogger *zap.Logger, tlsCert, tlsKey string) {
 		if err != nil {
 			logger.Sugar().Fatalf("failed get kube dns service,err: %v", err)
 		}
+
+		// If the ip address list is empty, the corresponding service does not exist or the selected label is incorrect
+		if len(dnsServiceIPs) == 0 {
+			logger.Sugar().Fatalf("failed get kube dns service: %v", "the corresponding service does not exist or the selected label is incorrect")
+		}
+
 		logger.Sugar().Infof("kube dns service %s ", dnsServiceIPs)
 		coreDnsAddr = fmt.Sprintf("%s:53", dnsServiceIPs[0])
 	}

pkg/k8ObjManager/service.go

@@ -9,6 +9,7 @@ import (
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/labels"
+	"os"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 )
 
@@ -98,8 +99,20 @@ func (nm *k8sObjManager) ListServicesDnsIP(ctx context.Context) ([]string, error
 	serviceList := new(corev1.ServiceList)
 	var err error
 	var result []string
+	// default dns service selector key:
+	selectorLabelKey := os.Getenv("DNS_SERVICE_SELECT_LABEL_KEY")
+	if len(selectorLabelKey) == 0 {
+		selectorLabelKey = "kubernetes.io/name"
+	}
+
+	// default dns service selector value: CoreDNS
+	selectorLabelValue := os.Getenv("DNS_SERVICE_SELECT_LABEL_VALUE")
+	if len(selectorLabelValue) == 0 {
+		selectorLabelValue = "CoreDNS"
+	}
+
 	label := map[string]string{
-		"k8s-app": "kube-dns",
+		selectorLabelKey: selectorLabelValue,
 	}
 	ListOption := &client.ListOptions{
 		Namespace:     "kube-system",