Add untracked metrics package

pkg/controller/metrics/metrics.go

@@ -0,0 +1,57 @@
+package metrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/metrics"
+)
+
+var (
+	AppRoutingReconcileTotal = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Name: "app_routing_reconcile_total",
+		Help: "Total number of reconciliations per controller",
+	}, []string{"controller", "result"})
+
+	AppRoutingReconcileErrors = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Name: "app_routing_reconcile_errors_total",
+		Help: "Total number of reconciliation errors per controller",
+	}, []string{"controller"})
+)
+
+const (
+	LabelError        = "error"
+	LabelRequeueAfter = "requeue_after"
+	LabelRequeue      = "requeue"
+	LabelSuccess      = "success"
+)
+
+func init() {
+	metrics.Registry.MustRegister(AppRoutingReconcileErrors, AppRoutingReconcileTotal)
+}
+
+// HandleControllerReconcileMetrics is meant to be called within a defer for each controller.
+// This lets us put all the metric handling in one place, rather than duplicating it in every controller
+func HandleControllerReconcileMetrics(controllerName string, result ctrl.Result, err error) {
+	switch {
+	// apierrors.IsNotFound is ignored by controllers so this should too
+	case err != nil && !apierrors.IsNotFound(err):
+		AppRoutingReconcileTotal.WithLabelValues(controllerName, LabelError).Inc()
+		AppRoutingReconcileErrors.WithLabelValues(controllerName).Inc()
+	case result.RequeueAfter > 0:
+		AppRoutingReconcileTotal.WithLabelValues(controllerName, LabelRequeueAfter).Inc()
+	case result.Requeue:
+		AppRoutingReconcileTotal.WithLabelValues(controllerName, LabelRequeue).Inc()
+	default:
+		AppRoutingReconcileTotal.WithLabelValues(controllerName, LabelSuccess).Inc()
+	}
+}
+
+func InitControllerMetrics(controllerName string) {
+	AppRoutingReconcileTotal.WithLabelValues(controllerName, LabelError).Add(0)
+	AppRoutingReconcileTotal.WithLabelValues(controllerName, LabelRequeueAfter).Add(0)
+	AppRoutingReconcileTotal.WithLabelValues(controllerName, LabelRequeue).Add(0)
+	AppRoutingReconcileTotal.WithLabelValues(controllerName, LabelSuccess).Add(0)
+
+	AppRoutingReconcileErrors.WithLabelValues(controllerName).Add(0)
+}