[Alerting]: Fix empty rules evaluation statuses (#32997)

* [Alerting]: Fix empty rules evaluation statuses

`GetRuleGroupAlertRules()` requires an non empty namespaceUID

* Include the namespace into the response

pkg/services/ngalert/api/api_prometheus.go

@@ -63,8 +63,12 @@ func (srv PrometheusSrv) RouteGetRuleStatuses(c *models.ReqContext) response.Res
 		return response.JSON(http.StatusInternalServerError, ruleResponse)
 	}
 
-	for _, groupId := range ruleGroupQuery.Result {
-		alertRuleQuery := ngmodels.ListRuleGroupAlertRulesQuery{OrgID: c.SignedInUser.OrgId, RuleGroup: groupId}
+	for _, r := range ruleGroupQuery.Result {
+		if len(r) < 3 {
+			continue
+		}
+		groupId, namespaceUID, namespace := r[0], r[1], r[2]
+		alertRuleQuery := ngmodels.ListRuleGroupAlertRulesQuery{OrgID: c.SignedInUser.OrgId, NamespaceUID: namespaceUID, RuleGroup: groupId}
 		if err := srv.store.GetRuleGroupAlertRules(&alertRuleQuery); err != nil {
 			ruleResponse.DiscoveryBase.Status = "error"
 			ruleResponse.DiscoveryBase.Error = fmt.Sprintf("failure getting rules for group %s: %s", groupId, err.Error())
@@ -73,8 +77,10 @@ func (srv PrometheusSrv) RouteGetRuleStatuses(c *models.ReqContext) response.Res
 		}
 
 		newGroup := &apimodels.RuleGroup{
-			Name:           groupId,
-			File:           "", // This doesn't make sense in our architecture but would be a good use case for provisioned alerts.
+			Name: groupId,
+			// This doesn't make sense in our architecture
+			// so we use this field for passing to the frontend the namaspace
+			File:           namespace,
 			LastEvaluation: time.Time{},
 			EvaluationTime: 0, // TODO: see if we are able to pass this along with evaluation results
 		}