BUG/MINOR: Fix an incorrect lookup of the Endpoints corresponding to a

Service Port

When looking to the Endpoints corresponding to a service Port we used to
match the Service Port (Service.ports[].Port) against the Endpoints Port
(TargetPort) which is incorrect because they are not necessarily the
same.
An example of ServicePort config that may trigger this bug:
 ports:
  - name: http
    port: 8080
    protocol: TCP
    targetPort: 80
  - name: http-alt
    port: 8888
    protocol: TCP
    targetPort: 8080
If an ingress rule is using the "http" service port, the controller may
pick the "http-alt" endpoints (instead of "http" ones) because http.8080
== http-atl.8080

The fix is to simply check if EndpointPort.Name == Service.ports[].Name
when looking for corresponding endpoints.

Author: Mo3m3n

controller/service/endpoints.go

@@ -154,13 +154,9 @@ func (s *Service) getRuntimeBackend(k8s store.K8s) (backend *store.RuntimeBacken
 		}
 		return nil, fmt.Errorf("no available endpoints")
 	}
-	sp := s.path.SvcPortResolved
-	if sp != nil {
-		for portName, backend := range backends {
-			if portName == sp.Name || backend.Endpoints.Port == sp.Port {
-				return backend, nil
-			}
-		}
+	svcPort := s.path.SvcPortResolved
+	if svcPort != nil && backends[svcPort.Name] != nil {
+		return backends[svcPort.Name], nil
 	}
 	if s.path.SvcPortString != "" {
 		return nil, fmt.Errorf("no matching endpoints for port '%s'", s.path.SvcPortString)