Retrieve DNS domain name from cluster

OVNDBCluster uses openshift dns name for Status.InternalDbAddress,
which the dnsrecord is created using the following pattern:
[pod_name].[namespace].[type(svc)].[ClusterDomain]
The default for ClusterDomain is 'cluster.local'
but this could change in the future as mentioned in [0].
With this patch the ClusterDomain is gathered from the
environment and not hardcoded.

[0] https://github.com/openshift/cluster-dns-operator/blob/208d50c1a5e0aaeb991366daa749abdffa803224/pkg/operator/controller/controller.go#L498

Jira: OSPRH-3627

config/rbac/role.yaml

@@ -143,6 +143,14 @@ rules:
   - patch
   - update
   - watch
+- apiGroups:
+  - operator.openshift.io
+  resources:
+  - dnses
+  verbs:
+  - get
+  - list
+  - watch
 - apiGroups:
   - ovn.openstack.org
   resources:

controllers/ovndbcluster_controller.go

@@ -37,6 +37,7 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/predicate"
 	"sigs.k8s.io/controller-runtime/pkg/reconcile"
 
+	operatorv1 "github.com/openshift/api/operator/v1"
 	infranetworkv1 "github.com/openstack-k8s-operators/infra-operator/apis/network/v1beta1"
 	"github.com/openstack-k8s-operators/lib-common/modules/common"
 	"github.com/openstack-k8s-operators/lib-common/modules/common/condition"
@@ -97,6 +98,7 @@ func (r *OVNDBClusterReconciler) GetLogger(ctx context.Context) logr.Logger {
 //+kubebuilder:rbac:groups=core,resources=pods,verbs=get;list;
 //+kubebuilder:rbac:groups=k8s.cni.cncf.io,resources=network-attachment-definitions,verbs=get;list;watch
 //+kubebuilder:rbac:groups=network.openstack.org,resources=dnsdata,verbs=get;list;watch;create;update;patch;delete
+//+kubebuilder:rbac:groups="operator.openshift.io",resources=dnses,verbs=get;list;watch
 
 // service account, role, rolebinding
 // +kubebuilder:rbac:groups="",resources=serviceaccounts,verbs=get;list;watch;create;update;patch
@@ -607,6 +609,8 @@ func (r *OVNDBClusterReconciler) reconcileNormal(ctx context.Context, instance *
 		internalDbAddress := []string{}
 		var svcPort int32
 		scheme := "tcp"
+		// Get DNS Cluster suffix
+		DNSSuffix := getDNSDomain(ctx, r.GetClient(), r.GetLogger(ctx))
 		if instance.Spec.TLS.Enabled() {
 			scheme = "ssl"
 		}
@@ -615,7 +619,7 @@ func (r *OVNDBClusterReconciler) reconcileNormal(ctx context.Context, instance *
 
 			// Filter out headless services
 			if svc.Spec.ClusterIP != "None" {
-				internalDbAddress = append(internalDbAddress, fmt.Sprintf("%s:%s.%s.svc.%s:%d", scheme, svc.Name, svc.Namespace, ovnv1.DNSSuffix, svcPort))
+				internalDbAddress = append(internalDbAddress, fmt.Sprintf("%s:%s.%s.svc.%s:%d", scheme, svc.Name, svc.Namespace, DNSSuffix, svcPort))
 			}
 		}
 
@@ -641,6 +645,23 @@ func (r *OVNDBClusterReconciler) reconcileNormal(ctx context.Context, instance *
 	return ctrl.Result{}, nil
 }
 
+func getDNSDomain(ctx context.Context, c client.Client, Log logr.Logger) string {
+	DNSDomain := ovnv1.DNSSuffix
+	DNSClusterInfoList := &operatorv1.DNSList{}
+	err := c.List(ctx, DNSClusterInfoList)
+	if err != nil {
+		Log.Info(fmt.Sprintf("Warning: Couldn't retrieve DNS cluster info, using default DNS Suffix: %s", DNSDomain))
+		return DNSDomain
+	}
+	// Using this approach in case CP have multiple domains
+	// also it does not depend on the DNS CR name.
+	// ATM in case of multiple domains will return last one.
+	for _, dns := range DNSClusterInfoList.Items {
+		DNSDomain = dns.Status.ClusterDomain
+	}
+	return DNSDomain
+}
+
 func getPodIPInNetwork(ovnPod corev1.Pod, namespace string, networkAttachment string) (string, error) {
 	netStat, err := nad.GetNetworkStatusFromAnnotation(ovnPod.Annotations)
 	if err != nil {

go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/k8snetworkplumbingwg/network-attachment-definition-client v1.7.5
 	github.com/onsi/ginkgo/v2 v2.20.1
 	github.com/onsi/gomega v1.34.1
+	github.com/openshift/api v3.9.0+incompatible
 	github.com/openstack-k8s-operators/infra-operator/apis v0.5.1-0.20241024081600-3e23dc62002c
 	github.com/openstack-k8s-operators/lib-common/modules/common v0.5.1-0.20241025164019-30baa23bf6f1
 	github.com/openstack-k8s-operators/lib-common/modules/test v0.5.1-0.20241025164019-30baa23bf6f1
@@ -47,7 +48,6 @@ require (
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
-	github.com/openshift/api v3.9.0+incompatible // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/prometheus/client_golang v1.18.0 // indirect
 	github.com/prometheus/client_model v0.5.0 // indirect

main.go

@@ -40,6 +40,7 @@ import (
 	metricsserver "sigs.k8s.io/controller-runtime/pkg/metrics/server"
 
 	networkv1 "github.com/k8snetworkplumbingwg/network-attachment-definition-client/pkg/apis/k8s.cni.cncf.io/v1"
+	operatorv1 "github.com/openshift/api/operator/v1"
 	infranetworkv1 "github.com/openstack-k8s-operators/infra-operator/apis/network/v1beta1"
 
 	ovnv1 "github.com/openstack-k8s-operators/ovn-operator/api/v1beta1"
@@ -57,6 +58,7 @@ func init() {
 	utilruntime.Must(ovnv1.AddToScheme(scheme))
 	utilruntime.Must(networkv1.AddToScheme(scheme))
 	utilruntime.Must(infranetworkv1.AddToScheme(scheme))
+	utilruntime.Must(operatorv1.AddToScheme(scheme))
 	//+kubebuilder:scaffold:scheme
 }