Use dns cluster info from lib common get function

Openshift coreDNS creates the domain name using an string
located in dnses.operator.openshift.io. This string can
change in the future, calling lib-common/GetDNSClusterDomain
the responsability of gathering this information correctly
only falls under lib-common intead of all operators.

Resolves: OSPRH-3627
Depends-on: openstack-k8s-operators/lib-common#580

pkg/redis/statefulset.go

@@ -9,6 +9,7 @@ import (
 	appsv1 "k8s.io/api/apps/v1"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"github.com/openstack-k8s-operators/lib-common/modules/common/clusterdns"
 	"k8s.io/apimachinery/pkg/util/intstr"
 )
 
@@ -61,6 +62,7 @@ func StatefulSet(
 		Port: intstr.IntOrString{Type: intstr.Int, IntVal: int32(26379)},
 	}
 	name := r.Name + "-" + "redis"
+	clusterDomain := clusterdns.GetDNSClusterDomain()
 
 	commonEnvVars := []corev1.EnvVar{{
 		Name:  "KOLLA_CONFIG_STRATEGY",
@@ -69,8 +71,7 @@ func StatefulSet(
 		Name: "SVC_FQDN",
 		// https://github.com/kubernetes/dns/blob/master/docs/specification.md
 		// Headless services only publish dns entries that include cluster domain.
-		// For the time being, assume this is .cluster.local
-		Value: name + "." + r.GetNamespace() + ".svc.cluster.local",
+		Value: name + "." + r.GetNamespace() + ".svc." + clusterDomain,
 	}, {
 		Name:  "CONFIG_HASH",
 		Value: configHash,