e2e: add -is-openshift option to disable certain checks

On OpenShift it is not possible for the Rook toolbox to get the metrics
from Kubelet (without additional configuration). By passing
-is-openshift, the metrics are not checked, and the e2e suite does not
fail on that particular piece.

Signed-off-by: Niels de Vos <ndevos@redhat.com>

e2e/utils.go

@@ -78,6 +78,7 @@ var (
 	rookNamespace    string
 	radosNamespace   string
 	poll             = 2 * time.Second
+	isOpenShift      bool
 )
 
 func getMons(ns string, c kubernetes.Interface) ([]string, error) {
@@ -404,7 +405,7 @@ func validateNormalUserPVCAccess(pvcPath string, f *framework.Framework) error {
 	if pvc.Spec.VolumeMode != nil {
 		isBlockMode = (*pvc.Spec.VolumeMode == v1.PersistentVolumeBlock)
 	}
-	if !isBlockMode || k8sVersionGreaterEquals(f.ClientSet, 1, 22) {
+	if (!isBlockMode || k8sVersionGreaterEquals(f.ClientSet, 1, 22)) && !isOpenShift {
 		err = getMetricsForPVC(f, pvc, deployTimeout)
 		if err != nil {
 			return err