minor fix for making map (#6076)

Signed-off-by: NYaoZengzeng <yaozengzeng@huawei.com>

discovery/kubernetes/ingress.go

@@ -144,7 +144,8 @@ const (
 )
 
 func ingressLabels(ingress *v1beta1.Ingress) model.LabelSet {
-	ls := make(model.LabelSet, len(ingress.Labels)+len(ingress.Annotations)+2)
+	// Each label and annotation will create two key-value pairs in the map.
+	ls := make(model.LabelSet, 2*(len(ingress.Labels)+len(ingress.Annotations))+2)
 	ls[ingressNameLabel] = lv(ingress.Name)
 	ls[namespaceLabel] = lv(ingress.Namespace)
 

discovery/kubernetes/node.go

@@ -151,7 +151,8 @@ const (
 )
 
 func nodeLabels(n *apiv1.Node) model.LabelSet {
-	ls := make(model.LabelSet, len(n.Labels)+len(n.Annotations)+1)
+	// Each label and annotation will create two key-value pairs in the map.
+	ls := make(model.LabelSet, 2*(len(n.Labels)+len(n.Annotations))+1)
 
 	ls[nodeNameLabel] = lv(n.Name)
 

discovery/kubernetes/service.go

@@ -149,7 +149,8 @@ const (
 )
 
 func serviceLabels(svc *apiv1.Service) model.LabelSet {
-	ls := make(model.LabelSet, len(svc.Labels)+len(svc.Annotations)+2)
+	// Each label and annotation will create two key-value pairs in the map.
+	ls := make(model.LabelSet, 2*(len(svc.Labels)+len(svc.Annotations))+2)
 
 	ls[serviceNameLabel] = lv(svc.Name)
 	ls[namespaceLabel] = lv(svc.Namespace)