Add metrics of RunnerDeployment and HRA (actions#408)

* Add metrics of RunnerDeployment and HRA

* Use kube-state-metrics-style label names

controllers/horizontalrunnerautoscaler_controller.go

@@ -34,6 +34,7 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+	"github.com/summerwind/actions-runner-controller/controllers/metrics"
 )
 
 const (
@@ -73,6 +74,8 @@ func (r *HorizontalRunnerAutoscalerReconciler) Reconcile(req ctrl.Request) (ctrl
 		return ctrl.Result{}, nil
 	}
 
+	metrics.SetHorizontalRunnerAutoscalerSpec(hra.ObjectMeta, hra.Spec)
+
 	var rd v1alpha1.RunnerDeployment
 	if err := r.Get(ctx, types.NamespacedName{
 		Namespace: req.Namespace,
@@ -145,6 +148,8 @@ func (r *HorizontalRunnerAutoscalerReconciler) Reconcile(req ctrl.Request) (ctrl
 	}
 
 	if updated != nil {
+		metrics.SetHorizontalRunnerAutoscalerStatus(updated.ObjectMeta, updated.Status)
+
 		if err := r.Status().Patch(ctx, updated, client.MergeFrom(&hra)); err != nil {
 			return ctrl.Result{}, fmt.Errorf("patching horizontalrunnerautoscaler status to add cache entry: %w", err)
 		}

controllers/metrics/horizontalrunnerautoscaler.go

@@ -0,0 +1,67 @@
+package metrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+const (
+	hraName      = "horizontalrunnerautoscaler"
+	hraNamespace = "namespace"
+)
+
+var (
+	horizontalRunnerAutoscalerMetrics = []prometheus.Collector{
+		horizontalRunnerAutoscalerMinReplicas,
+		horizontalRunnerAutoscalerMaxReplicas,
+		horizontalRunnerAutoscalerDesiredReplicas,
+	}
+)
+
+var (
+	horizontalRunnerAutoscalerMinReplicas = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Name: "horizontalrunnerautoscaler_spec_min_replicas",
+			Help: "minReplicas of HorizontalRunnerAutoscaler",
+		},
+		[]string{hraName, hraNamespace},
+	)
+	horizontalRunnerAutoscalerMaxReplicas = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Name: "horizontalrunnerautoscaler_spec_max_replicas",
+			Help: "maxReplicas of HorizontalRunnerAutoscaler",
+		},
+		[]string{hraName, hraNamespace},
+	)
+	horizontalRunnerAutoscalerDesiredReplicas = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Name: "horizontalrunnerautoscaler_status_desired_replicas",
+			Help: "desiredReplicas of HorizontalRunnerAutoscaler",
+		},
+		[]string{hraName, hraNamespace},
+	)
+)
+
+func SetHorizontalRunnerAutoscalerSpec(o metav1.ObjectMeta, spec v1alpha1.HorizontalRunnerAutoscalerSpec) {
+	labels := prometheus.Labels{
+		hraName:      o.Name,
+		hraNamespace: o.Namespace,
+	}
+	if spec.MaxReplicas != nil {
+		horizontalRunnerAutoscalerMaxReplicas.With(labels).Set(float64(*spec.MaxReplicas))
+	}
+	if spec.MinReplicas != nil {
+		horizontalRunnerAutoscalerMinReplicas.With(labels).Set(float64(*spec.MinReplicas))
+	}
+}
+
+func SetHorizontalRunnerAutoscalerStatus(o metav1.ObjectMeta, status v1alpha1.HorizontalRunnerAutoscalerStatus) {
+	labels := prometheus.Labels{
+		hraName:      o.Name,
+		hraNamespace: o.Namespace,
+	}
+	if status.DesiredReplicas != nil {
+		horizontalRunnerAutoscalerDesiredReplicas.With(labels).Set(float64(*status.DesiredReplicas))
+	}
+}

controllers/metrics/metrics.go

@@ -0,0 +1,14 @@
+// Package metrics provides the metrics of custom resources such as HRA.
+//
+// This depends on the metrics exporter of kubebuilder.
+// See https://book.kubebuilder.io/reference/metrics.html for details.
+package metrics
+
+import (
+	"sigs.k8s.io/controller-runtime/pkg/metrics"
+)
+
+func init() {
+	metrics.Registry.MustRegister(runnerDeploymentMetrics...)
+	metrics.Registry.MustRegister(horizontalRunnerAutoscalerMetrics...)
+}

controllers/metrics/runnerdeployment.go

@@ -0,0 +1,37 @@
+package metrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+)
+
+const (
+	rdName      = "runnerdeployment"
+	rdNamespace = "namespace"
+)
+
+var (
+	runnerDeploymentMetrics = []prometheus.Collector{
+		runnerDeploymentReplicas,
+	}
+)
+
+var (
+	runnerDeploymentReplicas = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Name: "runnerdeployment_spec_replicas",
+			Help: "replicas of RunnerDeployment",
+		},
+		[]string{rdName, rdNamespace},
+	)
+)
+
+func SetRunnerDeployment(rd v1alpha1.RunnerDeployment) {
+	labels := prometheus.Labels{
+		rdName:      rd.Name,
+		rdNamespace: rd.Namespace,
+	}
+	if rd.Spec.Replicas != nil {
+		runnerDeploymentReplicas.With(labels).Set(float64(*rd.Spec.Replicas))
+	}
+}

controllers/runnerdeployment_controller.go

@@ -38,6 +38,7 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+	"github.com/summerwind/actions-runner-controller/controllers/metrics"
 )
 
 const (
@@ -77,6 +78,8 @@ func (r *RunnerDeploymentReconciler) Reconcile(req ctrl.Request) (ctrl.Result, e
 		return ctrl.Result{}, nil
 	}
 
+	metrics.SetRunnerDeployment(rd)
+
 	var myRunnerReplicaSetList v1alpha1.RunnerReplicaSetList
 	if err := r.List(ctx, &myRunnerReplicaSetList, client.InNamespace(req.Namespace), client.MatchingFields{runnerSetOwnerKey: req.Name}); err != nil {
 		return ctrl.Result{}, err