Generate prom metrics periodically; Handle scanner-opa removal

pkg/apiserver/apiserver.go

@@ -377,5 +377,9 @@ func (c completedConfig) New(ctx context.Context) (*UIServer, error) {
 		}
 		m.Install(genericServer.Handler.NonGoRestfulMux)
 	}
+	if err := mgr.Add(manager.RunnableFunc(metricshandler.StartMetricsCollector(mgr))); err != nil {
+		setupLog.Error(err, "unable to start metrics collector")
+		os.Exit(1)
+	}
 	return s, nil
 }

pkg/graph/setup.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"fmt"
 	"strings"
+	"sync/atomic"
 	"time"
 
 	scannerapi "kubeops.dev/scanner/apis/scanner/v1alpha1"
@@ -56,6 +57,8 @@ func PollNewResourceTypes(cfg *restclient.Config, pqr *projectquotacontroller.Pr
 				klog.ErrorS(err, "failed to list server preferred resources")
 				return false, nil
 			}
+			opaInstalled := false
+			scannerInstalled := false
 			for _, rsList := range rsLists {
 				for _, rs := range rsList.APIResources {
 					// skip sub resource
@@ -85,6 +88,15 @@ func PollNewResourceTypes(cfg *restclient.Config, pqr *projectquotacontroller.Pr
 						Kind:    rs.Kind,
 						Scope:   scope,
 					}
+
+					// As we are generating metrics based on these variables, we need to update them timely.
+					if rid.Group == "templates.gatekeeper.sh" && rid.Kind == "ConstraintTemplate" {
+						opaInstalled = true
+					}
+					if rid.Group == scannerapi.SchemeGroupVersion.Group && rid.Kind == scannerapi.ResourceKindImageScanRequest {
+						scannerInstalled = true
+					}
+
 					if _, found := resourceTracker[gvk]; !found {
 						resourceTracker[gvk] = rid
 						resourceChannel <- rid
@@ -94,6 +106,10 @@ func PollNewResourceTypes(cfg *restclient.Config, pqr *projectquotacontroller.Pr
 					}
 				}
 			}
+
+			OPAInstalled.Store(opaInstalled)
+			ScannerInstalled.Store(scannerInstalled)
+
 			return false, nil
 		}, ctx.Done())
 		if err != nil {
@@ -106,13 +122,10 @@ func PollNewResourceTypes(cfg *restclient.Config, pqr *projectquotacontroller.Pr
 }
 
 var (
-	opaInstalled     bool
-	scannerInstalled bool
+	OPAInstalled     atomic.Bool
+	ScannerInstalled atomic.Bool
 )
 
-func OPAInstalled() bool     { return opaInstalled }
-func ScannerInstalled() bool { return scannerInstalled }
-
 func SetupGraphReconciler(mgr manager.Manager) func(ctx context.Context) error {
 	return func(ctx context.Context) error {
 		for rid := range resourceChannel {
@@ -124,13 +137,8 @@ func SetupGraphReconciler(mgr manager.Manager) func(ctx context.Context) error {
 				return err
 			}
 
-			if rid.Group == "templates.gatekeeper.sh" && rid.Kind == "ConstraintTemplate" {
-				opaInstalled = true
-			}
-
 			if rid.Group == scannerapi.SchemeGroupVersion.Group &&
 				rid.Kind == scannerapi.ResourceKindImageScanRequest {
-				scannerInstalled = true
 				if err := (&scannercontrollers.WorkloadReconciler{
 					Client: mgr.GetClient(),
 				}).SetupWithManager(mgr); err != nil {

pkg/metricshandler/ancestor.go

@@ -20,46 +20,43 @@ import (
 	"context"
 
 	"kubeops.dev/ui-server/pkg/graph"
-	"kubeops.dev/ui-server/pkg/metricsstore"
 
 	core "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/kube-state-metrics/v2/pkg/metric"
-	generator "k8s.io/kube-state-metrics/v2/pkg/metric_generator"
 	kmapi "kmodules.xyz/client-go/api/v1"
 	"kmodules.xyz/resource-metadata/apis/meta/v1alpha1"
-	"sigs.k8s.io/controller-runtime/pkg/client"
 )
 
-func collectPodAncestorMetrics(kc client.Client, generators []generator.FamilyGenerator, store *metricsstore.MetricsStore) error {
+func (mc *Collector) collectPodAncestorMetrics() error {
 	var pods core.PodList
-	err := kc.List(context.TODO(), &pods)
+	err := mc.kc.List(context.TODO(), &pods)
 	if err != nil {
 		return err
 	}
 
-	family := generators[0].Generate(nil)
+	family := mc.generators[0].Generate(nil)
 	for _, pod := range pods.Items {
-		g, err := getResourceGraph(kc, pod.ObjectMeta)
+		g, err := mc.getResourceGraph(pod.ObjectMeta)
 		if err != nil {
 			return err
 		}
 		family.Metrics = append(family.Metrics, getMetricsForSinglePod(g, pod.Name)...)
 	}
 
-	store.Add(family)
+	mc.store.Add(family)
 	return nil
 }
 
-func getResourceGraph(kc client.Client, podMeta metav1.ObjectMeta) (*v1alpha1.ResourceGraphResponse, error) {
+func (mc *Collector) getResourceGraph(podMeta metav1.ObjectMeta) (*v1alpha1.ResourceGraphResponse, error) {
 	src := kmapi.ObjectID{
 		Group:     "",
 		Kind:      "Pod",
 		Namespace: podMeta.Namespace,
 		Name:      podMeta.Name,
 	}
 
-	return graph.ResourceGraph(kc.RESTMapper(), src, []kmapi.EdgeLabel{
+	return graph.ResourceGraph(mc.kc.RESTMapper(), src, []kmapi.EdgeLabel{
 		kmapi.EdgeLabelOffshoot,
 	})
 }