fix(discovery): Handle cache.DeletedFinalStateUnknown in node informers' DeleteFunc

Signed-off-by: machine424 <ayoubmrini424@gmail.com>

discovery/kubernetes/endpoints.go

@@ -167,8 +167,11 @@ func NewEndpoints(l *slog.Logger, eps cache.SharedIndexInformer, svc, pod, node
 				e.enqueueNode(node.Name)
 			},
 			DeleteFunc: func(o interface{}) {
-				node := o.(*apiv1.Node)
-				e.enqueueNode(node.Name)
+				nodeName, err := nodeName(o)
+				if err != nil {
+					l.Error("Error getting Node name", "err", err)
+				}
+				e.enqueueNode(nodeName)
 			},
 		})
 		if err != nil {

discovery/kubernetes/endpointslice.go

@@ -145,8 +145,11 @@ func NewEndpointSlice(l *slog.Logger, eps cache.SharedIndexInformer, svc, pod, n
 				e.enqueueNode(node.Name)
 			},
 			DeleteFunc: func(o interface{}) {
-				node := o.(*apiv1.Node)
-				e.enqueueNode(node.Name)
+				nodeName, err := nodeName(o)
+				if err != nil {
+					l.Error("Error getting Node name", "err", err)
+				}
+				e.enqueueNode(nodeName)
 			},
 		})
 		if err != nil {

discovery/kubernetes/kubernetes.go

@@ -804,3 +804,13 @@ func addObjectMetaLabels(labelSet model.LabelSet, objectMeta metav1.ObjectMeta,
 func namespacedName(namespace, name string) string {
 	return namespace + "/" + name
 }
+
+// nodeName knows how to handle the cache.DeletedFinalStateUnknown tombstone.
+// It assumes the MetaNamespaceKeyFunc keyFunc is used, which uses the node name as the tombstone key.
+func nodeName(o interface{}) (string, error) {
+	key, err := cache.DeletionHandlingMetaNamespaceKeyFunc(o)
+	if err != nil {
+		return "", err
+	}
+	return key, nil
+}

discovery/kubernetes/kubernetes_test.go

@@ -23,7 +23,9 @@ import (
 	prom_testutil "github.com/prometheus/client_golang/prometheus/testutil"
 	"github.com/prometheus/common/promslog"
 	"github.com/stretchr/testify/require"
+	apiv1 "k8s.io/api/core/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/version"
 	"k8s.io/apimachinery/pkg/watch"
@@ -320,3 +322,18 @@ func TestFailuresCountMetric(t *testing.T) {
 		})
 	}
 }
+
+func TestNodeName(t *testing.T) {
+	node := &apiv1.Node{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "foo",
+		},
+	}
+	name, err := nodeName(node)
+	require.NoError(t, err)
+	require.Equal(t, "foo", name)
+
+	name, err = nodeName(cache.DeletedFinalStateUnknown{Key: "bar"})
+	require.NoError(t, err)
+	require.Equal(t, "bar", name)
+}

discovery/kubernetes/node.go

@@ -82,7 +82,7 @@ func NewNode(l *slog.Logger, inf cache.SharedInformer, eventCount *prometheus.Co
 }
 
 func (n *Node) enqueue(obj interface{}) {
-	key, err := cache.DeletionHandlingMetaNamespaceKeyFunc(obj)
+	key, err := nodeName(obj)
 	if err != nil {
 		return
 	}

discovery/kubernetes/pod.go

@@ -95,8 +95,11 @@ func NewPod(l *slog.Logger, pods cache.SharedIndexInformer, nodes cache.SharedIn
 				p.enqueuePodsForNode(node.Name)
 			},
 			DeleteFunc: func(o interface{}) {
-				node := o.(*apiv1.Node)
-				p.enqueuePodsForNode(node.Name)
+				nodeName, err := nodeName(o)
+				if err != nil {
+					l.Error("Error getting Node name", "err", err)
+				}
+				p.enqueuePodsForNode(nodeName)
 			},
 		})
 		if err != nil {