⚠️ Remove duplicate QueueLength metric

The QueueLength metric is now a duplicate of the workqueue "depth"
metric, so it's no longer needed.

pkg/internal/controller/controller.go

@@ -248,6 +248,5 @@ func (c *Controller) InjectFunc(f inject.Func) error {
 
 // updateMetrics updates prometheus metrics within the controller
 func (c *Controller) updateMetrics(reconcileTime time.Duration) {
-	ctrlmetrics.QueueLength.WithLabelValues(c.Name).Set(float64(c.Queue.Len()))
 	ctrlmetrics.ReconcileTime.WithLabelValues(c.Name).Observe(reconcileTime.Seconds())
 }

pkg/internal/controller/controller_test.go

@@ -533,16 +533,7 @@ var _ = Describe("controller", func() {
 
 		Context("should update prometheus metrics", func() {
 			It("should requeue a Request if there is an error and continue processing items", func(done Done) {
-				var queueLength, reconcileErrs dto.Metric
-				ctrlmetrics.QueueLength.Reset()
-				Expect(func() error {
-					ctrlmetrics.QueueLength.WithLabelValues(ctrl.Name).Write(&queueLength)
-					if queueLength.GetGauge().GetValue() != 0.0 {
-						return fmt.Errorf("metric queue length not reset")
-					}
-					return nil
-				}()).Should(Succeed())
-
+				var reconcileErrs dto.Metric
 				ctrlmetrics.ReconcileErrors.Reset()
 				Expect(func() error {
 					ctrlmetrics.ReconcileErrors.WithLabelValues(ctrl.Name).Write(&reconcileErrs)
@@ -564,13 +555,6 @@ var _ = Describe("controller", func() {
 
 				By("Invoking Reconciler which will give an error")
 				Expect(<-reconciled).To(Equal(request))
-				Eventually(func() error {
-					ctrlmetrics.QueueLength.WithLabelValues(ctrl.Name).Write(&queueLength)
-					if queueLength.GetGauge().GetValue() != 1.0 {
-						return fmt.Errorf("metric queue length not updated")
-					}
-					return nil
-				}, 2.0).Should(Succeed())
 				Eventually(func() error {
 					ctrlmetrics.ReconcileErrors.WithLabelValues(ctrl.Name).Write(&reconcileErrs)
 					if reconcileErrs.GetCounter().GetValue() != 1.0 {

pkg/internal/controller/metrics/metrics.go

@@ -22,13 +22,6 @@ import (
 )
 
 var (
-	// QueueLength is a prometheus metric which counts the current reconcile
-	// queue length per controller
-	QueueLength = prometheus.NewGaugeVec(prometheus.GaugeOpts{
-		Name: "controller_runtime_reconcile_queue_length",
-		Help: "Length of reconcile queue per controller",
-	}, []string{"controller"})
-
 	// ReconcileTotal is a prometheus counter metrics which holds the total
 	// number of reconciliations per controller. It has two labels. controller label refers
 	// to the controller name and result label refers to the reconcile result i.e
@@ -55,7 +48,6 @@ var (
 
 func init() {
 	metrics.Registry.MustRegister(
-		QueueLength,
 		ReconcileTotal,
 		ReconcileErrors,
 		ReconcileTime,