feat(certmanager): add metrics for the reconciler

Signed-off-by: Khaled Emara <[email protected]>

certmanager/controller.go

@@ -7,12 +7,14 @@ import (
 
 	"github.com/go-logr/logr"
 	"github.com/kyverno/pkg/tls"
+	"github.com/prometheus/client_golang/prometheus"
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/client-go/tools/record"
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/controller-runtime/pkg/log"
+	"sigs.k8s.io/controller-runtime/pkg/metrics"
 	"sigs.k8s.io/controller-runtime/pkg/predicate"
 )
 
@@ -21,6 +23,21 @@ const (
 	maxRetries     = 10
 )
 
+var (
+	reconcileCount = prometheus.NewCounter(prometheus.CounterOpts{
+		Name: "certmanager_controller_reconcile_total",
+		Help: "Total number of reconciliations.",
+	})
+	requeueCount = prometheus.NewCounter(prometheus.CounterOpts{
+		Name: "certmanager_controller_requeue_total",
+		Help: "Total number of requeues.",
+	})
+	droppedCount = prometheus.NewCounter(prometheus.CounterOpts{
+		Name: "certmanager_controller_dropped_total",
+		Help: "Total number of objects dropped from the queue.",
+	})
+)
+
 type CertController struct {
 	client.Client
 	Scheme *runtime.Scheme
@@ -51,18 +68,17 @@ func NewController(
 	}
 }
 
-//+kubebuilder:rbac:groups=core,resources=secrets,verbs=get;list;watch
-//+kubebuilder:rbac:groups=core,resources=secrets,verbs=create;update
-//+kubebuilder:rbac:groups=core,resources=events,verbs=create;patch
-
 func (r *CertController) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
 	logger := log.FromContext(ctx)
+	reconcileCount.Inc()
 
 	if req.Namespace != r.namespace {
+		droppedCount.Inc()
 		return ctrl.Result{}, nil
 	}
 
 	if req.Name != r.caSecretName && req.Name != r.tlsSecretName {
+		droppedCount.Inc()
 		return ctrl.Result{}, nil
 	}
 
@@ -72,6 +88,7 @@ func (r *CertController) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.
 		return ctrl.Result{}, err
 	}
 
+	requeueCount.Inc()
 	return ctrl.Result{
 		RequeueAfter: tls.CertRenewalInterval,
 	}, nil
@@ -124,3 +141,7 @@ func RetryFunc(ctx context.Context, retryInterval, timeout time.Duration, logger
 		}
 	}
 }
+
+func init() {
+	metrics.Registry.MustRegister(reconcileCount, requeueCount, droppedCount)
+}