plugin/kubernetes: fix tombstone unwrapping (#3924)

* fix tombstone unwrapping

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

plugin/kubernetes/object/endpoint.go

@@ -1,6 +1,8 @@
 package object
 
 import (
+	"fmt"
+
 	api "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 )
@@ -43,8 +45,19 @@ type EndpointPort struct {
 // EndpointsKey return a string using for the index.
 func EndpointsKey(name, namespace string) string { return name + "." + namespace }
 
-// ToEndpoints converts an api.Endpoints to a *Endpoints.
-func ToEndpoints(end *api.Endpoints) *Endpoints {
+// ToEndpoints returns a function that converts an *api.Endpoints to a *Endpoints.
+func ToEndpoints(skipCleanup bool) ToFunc {
+	return func(obj interface{}) (interface{}, error) {
+		eps, ok := obj.(*api.Endpoints)
+		if !ok {
+			return nil, fmt.Errorf("unexpected object %v", obj)
+		}
+		return toEndpoints(skipCleanup, eps), nil
+	}
+}
+
+// toEndpoints converts an *api.Endpoints to a *Endpoints.
+func toEndpoints(skipCleanup bool, end *api.Endpoints) *Endpoints {
 	e := &Endpoints{
 		Version:   end.GetResourceVersion(),
 		Name:      end.GetName(),
@@ -88,6 +101,10 @@ func ToEndpoints(end *api.Endpoints) *Endpoints {
 		}
 	}
 
+	if !skipCleanup {
+		*end = api.Endpoints{}
+	}
+
 	return e
 }