detect if the cluster has endpoint slices

the endpoint slice controller was checking if the kubernetes
version was greater than 1.20 in order to run, so it can verify
the dual-stack api was implemented.

Since the endpoint slice controller in ovn can run with or without
the dualstack api, we only need to check that the API for slices
is enabled.

Signed-off-by: Antonio Ojea <aojea@redhat.com>

go-controller/pkg/util/kube.go

@@ -3,7 +3,6 @@ package util
 import (
 	"encoding/json"
 	"fmt"
-	"strconv"
 	"strings"
 
 	kapi "k8s.io/api/core/v1"
@@ -240,22 +239,11 @@ func EventRecorder(kubeClient kubernetes.Interface) record.EventRecorder {
 	return recorder
 }
 
-// UseEndpointSlices if the EndpointSlice API is available
-// and if the kubernetes versions supports DualStack (Kubernetes >= 1.20)
+// UseEndpointSlices detect if Endpoints Slices are enabled in the cluster
 func UseEndpointSlices(kubeClient kubernetes.Interface) bool {
-	endpointSlicesEnabled := false
 	if _, err := kubeClient.Discovery().ServerResourcesForGroupVersion(discovery.SchemeGroupVersion.String()); err == nil {
-		// The EndpointSlice API is enabled check if is running in a supported version
 		klog.V(2).Infof("Kubernetes Endpoint Slices enabled on the cluster: %s", discovery.SchemeGroupVersion.String())
-		endpointSlicesEnabled = true
+		return true
 	}
-	// We only use Slices if > 1.19 since we only need them for Dual Stack
-	sv, _ := kubeClient.Discovery().ServerVersion()
-	major, _ := strconv.Atoi(sv.Major)
-	minor, _ := strconv.Atoi(sv.Minor)
-	klog.Infof("Kubernetes running with version %d.%d", major, minor)
-	if major <= 1 && minor < 20 || !endpointSlicesEnabled {
-		return false
-	}
-	return true
+	return false
 }