account for nil holderIdentity case

Author: lantingchiang

internal/store/lease.go

@@ -42,13 +42,18 @@ var (
 			wrapLeaseFunc(func(l *coordinationv1.Lease) *metric.Family {
 				labelKeys := []string{"owner_kind", "owner_name", "namespace", "lease_holder"}
 
+				var holder string
+				if l.Spec.HolderIdentity != nil {
+					holder = *l.Spec.HolderIdentity
+				}
+
 				owners := l.GetOwnerReferences()
 				if len(owners) == 0 {
 					return &metric.Family{
 						Metrics: []*metric.Metric{
 							{
 								LabelKeys:   labelKeys,
-								LabelValues: []string{"<none>", "<none>", l.Namespace, *l.Spec.HolderIdentity},
+								LabelValues: []string{"<none>", "<none>", l.Namespace, holder},
 								Value:       1,
 							},
 						},
@@ -59,7 +64,7 @@ var (
 				for i, owner := range owners {
 					ms[i] = &metric.Metric{
 						LabelKeys:   labelKeys,
-						LabelValues: []string{owner.Kind, owner.Name, l.Namespace, *l.Spec.HolderIdentity},
+						LabelValues: []string{owner.Kind, owner.Name, l.Namespace, holder},
 						Value:       1,
 					}
 				}

internal/store/lease_test.go

@@ -57,6 +57,33 @@ func TestLeaseStore(t *testing.T) {
 				},
 				Want: metadata + `
                     kube_lease_owner{lease="kube-master",owner_kind="Node",owner_name="kube-master",namespace="default",lease_holder="kube-master"} 1
+                    kube_lease_renew_time{lease="kube-master"} 1.5e+09
+			`,
+				MetricNames: []string{
+					"kube_lease_owner",
+					"kube_lease_renew_time",
+				},
+			},
+			{
+				Obj: &coordinationv1.Lease{
+					ObjectMeta: metav1.ObjectMeta{
+						Generation:        2,
+						Name:              "kube-master",
+						Namespace:         "default",
+						CreationTimestamp: metav1.Time{Time: time.Unix(1500000000, 0)},
+						OwnerReferences: []metav1.OwnerReference{
+							{
+								Kind: "Node",
+								Name: leaseOwner,
+							},
+						},
+					},
+					Spec: coordinationv1.LeaseSpec{
+						RenewTime: &metav1.MicroTime{Time: time.Unix(1500000000, 0)},
+					},
+				},
+				Want: metadata + `
+                    kube_lease_owner{lease="kube-master",owner_kind="Node",owner_name="kube-master",namespace="default",lease_holder=""} 1
                     kube_lease_renew_time{lease="kube-master"} 1.5e+09
 			`,
 				MetricNames: []string{