Clear conntrack entries for externalIP

When an endpoint is deleted, the conntrack entries are cleared for
clusterIP but not for externalIP of the service. This change adds
that step.

pkg/proxy/types.go

@@ -19,7 +19,7 @@ package proxy
 import (
 	"fmt"
 
-	"k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/types"
 )
 
@@ -50,6 +50,8 @@ type ServicePort interface {
 	String() string
 	// ClusterIPString returns service cluster IP in string format.
 	ClusterIPString() string
+	// ExternalIPStrings returns service ExternalIPs as a string array.
+	ExternalIPStrings() []string
 	// GetProtocol returns service protocol.
 	GetProtocol() v1.Protocol
 	// GetHealthCheckNodePort returns service health check node port if present.  If return 0, it means not present.