Add OVS database server metrics collection support

This change adds support for collecting metrics from OVS database
servers (ovsdbserver) in both northbound (NB) and southbound (SB)
configurations. The implementation adds two new scrape configuration
functions that discover OVS DB server metrics services using label
selectors and automatically configure Prometheus to scrape them.

Changes include:
- New createOVSDBServerNBScrapeConfig() function for NB database metrics
- New createOVSDBServerSBScrapeConfig() function for SB database metrics
- Updated service watch function to trigger reconciliation when OVS DB
  server services change
- Both functions follow existing patterns and use "ovsdbserver-nb" and
  "ovsdbserver-sb" service labels respectively

This enables comprehensive monitoring of the OVN database layer,
complementing the existing OVN Northd and Controller metrics collection.

Depends-On: openstack-k8s-operators/openstack-operator#1609
Resolves: https://issues.redhat.com/browse/OSPRH-12569
Assisted-by: Claude
Signed-off-by: Miguel Lavalle <[email protected]>

Author: Miguel Lavalle

controllers/metricstorage_controller.go

@@ -873,6 +873,18 @@ func (r *MetricStorageReconciler) createScrapeConfigs(
 		return ctrl.Result{}, err
 	}
 
+	// ScrapeConfig for OVS DB Server NB metrics
+	err = r.createOVSDBServerNBScrapeConfig(ctx, instance, helper, serviceLabels)
+	if err != nil {
+		return ctrl.Result{}, err
+	}
+
+	// ScrapeConfig for OVS DB Server SB metrics
+	err = r.createOVSDBServerSBScrapeConfig(ctx, instance, helper, serviceLabels)
+	if err != nil {
+		return ctrl.Result{}, err
+	}
+
 	instance.Status.Conditions.MarkTrue(telemetryv1.ScrapeConfigReadyCondition, condition.ReadyMessage)
 	return ctrl.Result{}, nil
 }
@@ -1049,6 +1061,44 @@ func (r *MetricStorageReconciler) createOVNControllerScrapeConfig(
 	)
 }
 
+// createOVSDBServerNBScrapeConfig creates a scrape configuration for OVS DB Server NB metrics
+// This function discovers OVS DB Server NB metrics services using label selectors
+func (r *MetricStorageReconciler) createOVSDBServerNBScrapeConfig(
+	ctx context.Context,
+	instance *telemetryv1.MetricStorage,
+	helper *helper.Helper,
+	serviceLabels map[string]string,
+) error {
+	labelSelector := map[string]string{
+		"metrics": "enabled",
+		"service": "ovsdbserver-nb",
+	}
+	ovsdbServerNBCfgName := fmt.Sprintf("%s-ovsdbserver-nb", telemetry.ServiceName)
+	return r.createServiceScrapeConfigFromLabelSelector(
+		ctx, instance, helper, serviceLabels,
+		labelSelector, "metrics", ovsdbServerNBCfgName, "OVS DB server NB",
+	)
+}
+
+// createOVSDBServerSBScrapeConfig creates a scrape configuration for OVS DB Server SB metrics
+// This function discovers OVS DB Server SB metrics services using label selectors
+func (r *MetricStorageReconciler) createOVSDBServerSBScrapeConfig(
+	ctx context.Context,
+	instance *telemetryv1.MetricStorage,
+	helper *helper.Helper,
+	serviceLabels map[string]string,
+) error {
+	labelSelector := map[string]string{
+		"metrics": "enabled",
+		"service": "ovsdbserver-sb",
+	}
+	ovsdbServerSBCfgName := fmt.Sprintf("%s-ovsdbserver-sb", telemetry.ServiceName)
+	return r.createServiceScrapeConfigFromLabelSelector(
+		ctx, instance, helper, serviceLabels,
+		labelSelector, "metrics", ovsdbServerSBCfgName, "OVS DB server SB",
+	)
+}
+
 func (r *MetricStorageReconciler) createDashboardObjects(ctx context.Context, instance *telemetryv1.MetricStorage, helper *helper.Helper, eventHandler handler.EventHandler) (ctrl.Result, error) {
 	Log := r.GetLogger(ctx)
 	uiPluginObj := &obsui.UIPlugin{
@@ -1465,7 +1515,7 @@ func (r *MetricStorageReconciler) SetupWithManager(ctx context.Context, mgr ctrl
 
 		// Watch OVN metrics services
 		if labels := o.GetLabels(); labels != nil {
-			if labels["metrics"] == "enabled" && (labels["service"] == "ovn-northd" || labels["service"] == "ovn-controller-metrics") {
+			if labels["metrics"] == "enabled" && (labels["service"] == "ovn-northd" || labels["service"] == "ovn-controller-metrics" || labels["service"] == "ovsdbserver-nb" || labels["service"] == "ovsdbserver-sb") {
 				// get all metricstorage CRs in the same namespace
 				metricStorages := &telemetryv1.MetricStorageList{}
 				listOpts := []client.ListOption{