operator: Add watch on the Alertmanager in OCP's user-workload-monitoring namespace (#8038)

operator/CHANGELOG.md

@@ -1,5 +1,6 @@
 ## Main
 
+- [8038](https://github.com/grafana/loki/pull/8038) **aminesnow**: Add watch on the Alertmanager in OCP's user-workload-monitoring namespace
 - [8173](https://github.com/grafana/loki/pull/8173) **periklis**: Remove custom webhook cert mounts for OLM-based deployment (OpenShift)
 - [8001](https://github.com/grafana/loki/pull/8001) **aminesnow**: Add API validation to Alertmanager header auth config
 - [8087](https://github.com/grafana/loki/pull/8087) **xperimental**: Fix status not updating when state of pods changes

operator/controllers/loki/lokistack_controller.go

@@ -9,6 +9,7 @@ import (
 	"github.com/grafana/loki/operator/controllers/loki/internal/management/state"
 	"github.com/grafana/loki/operator/internal/external/k8s"
 	"github.com/grafana/loki/operator/internal/handlers"
+	"github.com/grafana/loki/operator/internal/manifests/openshift"
 	"github.com/grafana/loki/operator/internal/status"
 	openshiftconfigv1 "github.com/openshift/api/config/v1"
 	routev1 "github.com/openshift/api/route/v1"
@@ -92,6 +93,15 @@ var (
 			return false
 		},
 	})
+	createUpdateOrDeletePred = builder.WithPredicates(predicate.Funcs{
+		UpdateFunc: func(e event.UpdateEvent) bool {
+			return (e.ObjectOld.GetGeneration() != e.ObjectNew.GetGeneration()) ||
+				cmp.Diff(e.ObjectOld.GetAnnotations(), e.ObjectNew.GetAnnotations()) != ""
+		},
+		CreateFunc:  func(e event.CreateEvent) bool { return true },
+		DeleteFunc:  func(e event.DeleteEvent) bool { return true },
+		GenericFunc: func(e event.GenericEvent) bool { return false },
+	})
 )
 
 // LokiStackReconciler reconciles a LokiStack object
@@ -194,7 +204,8 @@ func (r *LokiStackReconciler) buildController(bld k8s.Builder) error {
 		Owns(&rbacv1.ClusterRole{}, updateOrDeleteOnlyPred).
 		Owns(&rbacv1.ClusterRoleBinding{}, updateOrDeleteOnlyPred).
 		Owns(&rbacv1.Role{}, updateOrDeleteOnlyPred).
-		Owns(&rbacv1.RoleBinding{}, updateOrDeleteOnlyPred)
+		Owns(&rbacv1.RoleBinding{}, updateOrDeleteOnlyPred).
+		Watches(&source.Kind{Type: &corev1.Service{}}, r.enqueueForUserWorkloadAMService(), createUpdateOrDeletePred)
 
 	if r.FeatureGates.LokiStackAlerts {
 		bld = bld.Owns(&monitoringv1.PrometheusRule{}, updateOrDeleteOnlyPred)
@@ -253,3 +264,34 @@ func statusDifferent(e event.UpdateEvent) bool {
 		return false
 	}
 }
+
+func (r *LokiStackReconciler) enqueueForUserWorkloadAMService() handler.EventHandler {
+	ctx := context.TODO()
+	return handler.EnqueueRequestsFromMapFunc(func(obj client.Object) []reconcile.Request {
+		lokiStacks := &lokiv1.LokiStackList{}
+		if err := r.Client.List(ctx, lokiStacks); err != nil {
+			r.Log.Error(err, "Error getting LokiStack resources in event handler")
+			return nil
+		}
+		var requests []reconcile.Request
+
+		if obj.GetName() == openshift.MonitoringSVCOperated && obj.GetNamespace() == openshift.MonitoringUserwWrkloadNS {
+
+			for _, stack := range lokiStacks.Items {
+				if stack.Spec.Tenants != nil && (stack.Spec.Tenants.Mode == lokiv1.OpenshiftLogging ||
+					stack.Spec.Tenants.Mode == lokiv1.OpenshiftNetwork) {
+					requests = append(requests, reconcile.Request{
+						NamespacedName: types.NamespacedName{
+							Namespace: stack.Namespace,
+							Name:      stack.Name,
+						},
+					})
+				}
+			}
+
+			r.Log.Info("Enqueued requests for all LokiStacks because of UserWorkload Alertmanager Service resource change", "count", len(requests), "kind", obj.GetObjectKind())
+		}
+
+		return requests
+	})
+}

operator/controllers/loki/lokistack_controller_test.go

@@ -57,6 +57,7 @@ func TestLokiStackController_RegistersCustomResourceForCreateOrUpdate(t *testing
 
 	b.ForReturns(b)
 	b.OwnsReturns(b)
+	b.WatchesReturns(b)
 
 	err := c.buildController(b)
 	require.NoError(t, err)
@@ -202,8 +203,8 @@ func TestLokiStackController_RegisterWatchedResources(t *testing.T) {
 	table := []test{
 		{
 			src:               &source.Kind{Type: &openshiftconfigv1.APIServer{}},
-			index:             0,
-			watchesCallsCount: 1,
+			index:             1,
+			watchesCallsCount: 2,
 			featureGates: configv1.FeatureGates{
 				OpenShift: configv1.OpenShiftFeatureGates{
 					ClusterTLSPolicy: true,
@@ -213,8 +214,8 @@ func TestLokiStackController_RegisterWatchedResources(t *testing.T) {
 		},
 		{
 			src:               &source.Kind{Type: &openshiftconfigv1.Proxy{}},
-			index:             0,
-			watchesCallsCount: 1,
+			index:             1,
+			watchesCallsCount: 2,
 			featureGates: configv1.FeatureGates{
 				OpenShift: configv1.OpenShiftFeatureGates{
 					ClusterProxy: true,
@@ -222,6 +223,13 @@ func TestLokiStackController_RegisterWatchedResources(t *testing.T) {
 			},
 			pred: updateOrDeleteOnlyPred,
 		},
+		{
+			src:               &source.Kind{Type: &corev1.Service{}},
+			index:             0,
+			watchesCallsCount: 1,
+			featureGates:      configv1.FeatureGates{},
+			pred:              createUpdateOrDeletePred,
+		},
 	}
 	for _, tst := range table {
 		b := &k8sfakes.FakeBuilder{}