Service Topology implementation

* Implement Service Topology for ipvs and iptables proxier
* Add test files
* API validation

pkg/proxy/types.go

@@ -30,6 +30,7 @@ type Provider interface {
 	config.EndpointsHandler
 	config.EndpointSliceHandler
 	config.ServiceHandler
+	config.NodeHandler
 
 	// Sync immediately synchronizes the Provider's current state to proxy rules.
 	Sync()
@@ -77,6 +78,8 @@ type ServicePort interface {
 	NodePort() int
 	// GetOnlyNodeLocalEndpoints returns if a service has only node local endpoints
 	OnlyNodeLocalEndpoints() bool
+	// TopologyKeys returns service TopologyKeys as a string array.
+	TopologyKeys() []string
 }
 
 // Endpoint in an interface which abstracts information about an endpoint.
@@ -87,6 +90,8 @@ type Endpoint interface {
 	String() string
 	// GetIsLocal returns true if the endpoint is running in same host as kube-proxy, otherwise returns false.
 	GetIsLocal() bool
+	// GetTopology returns the topology information of the endpoint.
+	GetTopology() map[string]string
 	// IP returns IP part of the endpoint.
 	IP() string
 	// Port returns the Port part of the endpoint.