feat: add RouteAdded and RouteDeleted metrics

Author: Soha-Albaghdady

src/code.cloudfoundry.org/gorouter/metrics/compositereporter.go

@@ -39,6 +39,8 @@ type MetricReporter interface {
 	CaptureRoutesPruned(prunedRoutes uint64)
 	CaptureLookupTime(t time.Duration)
 	CaptureRegistryMessage(msg ComponentTagged, action string)
+	CaptureRouteAdded()
+	CaptureRouteDeleted()
 	CaptureRouteRegistrationLatency(t time.Duration)
 	CaptureUnregistryMessage(msg ComponentTagged)
 	CaptureFoundFileDescriptors(files int)
@@ -198,6 +200,18 @@ func (m MultiMetricReporter) CaptureUnregistryMessage(msg ComponentTagged) {
 	}
 }
 
+func (m MultiMetricReporter) CaptureRouteAdded() {
+	for _, r := range m {
+		r.CaptureRouteAdded()
+	}
+}
+
+func (m MultiMetricReporter) CaptureRouteDeleted() {
+	for _, r := range m {
+		r.CaptureRouteAdded()
+	}
+}
+
 func (m MultiMetricReporter) CaptureFoundFileDescriptors(files int) {
 	for _, r := range m {
 		r.CaptureFoundFileDescriptors(files)

src/code.cloudfoundry.org/gorouter/metrics/fakes/fake_metricreporter.go

@@ -168,6 +168,14 @@ func (m *Metrics) CaptureUnregistryMessage(msg ComponentTagged) {
 	}
 }
 
+func (m *Metrics) CaptureRouteAdded() {
+	m.Batcher.BatchIncrementCounter("routes_added")
+}
+
+func (m *Metrics) CaptureRouteDeleted() {
+	m.Batcher.BatchIncrementCounter("routes_deleted")
+}
+
 func (m *Metrics) CaptureWebSocketUpdate() {
 	m.Batcher.BatchIncrementCounter("websocket_upgrades")
 }

src/code.cloudfoundry.org/gorouter/metrics/fakes/fake_varzreporter.go

@@ -524,6 +524,18 @@ var _ = Describe("MetricsReporter", func() {
 		Expect(count).To(Equal(uint64(5)))
 	})
 
+	It("increments the bad_requests metric", func() {
+		metricReporter.CaptureRouteAdded()
+		Expect(batcher.BatchIncrementCounterCallCount()).To(Equal(1))
+		Expect(batcher.BatchIncrementCounterArgsForCall(0)).To(Equal("routes_added"))
+	})
+
+	It("increments the bad_requests metric", func() {
+		metricReporter.CaptureRouteDeleted()
+		Expect(batcher.BatchIncrementCounterCallCount()).To(Equal(1))
+		Expect(batcher.BatchIncrementCounterArgsForCall(0)).To(Equal("routes_deleted"))
+	})
+
 	It("increments the backend_tls_handshake_failed metric", func() {
 		metricReporter.CaptureBackendTLSHandshakeFailed()
 		Expect(batcher.BatchIncrementCounterCallCount()).To(Equal(1))

src/code.cloudfoundry.org/gorouter/metrics/metricsreporter.go

@@ -18,6 +18,8 @@ type Metrics struct {
 	RouteRegistration           mr.CounterVec
 	RouteUnregistration         mr.CounterVec
 	RoutesPruned                mr.Counter
+	RoutesAdded                 mr.Counter
+	RoutesDeleted               mr.Counter
 	TotalRoutes                 mr.Gauge
 	TimeSinceLastRegistryUpdate mr.Gauge
 	RouteLookupTime             mr.Histogram
@@ -64,6 +66,8 @@ func NewMetrics(registry *mr.Registry, perRequestMetricsReporting bool, meterCon
 		RouteRegistration:           registry.NewCounterVec("registry_message", "number of route registration messages", []string{"component", "action"}),
 		RouteUnregistration:         registry.NewCounterVec("unregistry_message", "number of unregister messages", []string{"component"}),
 		RoutesPruned:                registry.NewCounter("routes_pruned", "number of pruned routes"),
+		RoutesAdded:                 registry.NewCounter("routes_added", "number of added routes"),
+		RoutesDeleted:               registry.NewCounter("routes_deleted", "number of deleted routes"),
 		TotalRoutes:                 registry.NewGauge("total_routes", "number of total routes"),
 		TimeSinceLastRegistryUpdate: registry.NewGauge("ms_since_last_registry_update", "time since last registry update in ms"),
 		RouteLookupTime:             registry.NewHistogram("route_lookup_time", "route lookup time per request in ns", meterConfig.RouteLookupTimeHistogramBuckets),
@@ -107,6 +111,13 @@ func (metrics *Metrics) CaptureRoutesPruned(routesPruned uint64) {
 	metrics.RoutesPruned.Add(float64(routesPruned))
 }
 
+func (metrics *Metrics) CaptureRouteAdded() {
+	metrics.RoutesAdded.Add(1)
+}
+
+func (metrics *Metrics) CaptureRouteDeleted() {
+	metrics.RoutesDeleted.Add(1)
+}
 func (metrics *Metrics) CaptureTotalRoutes(totalRoutes int) {
 	metrics.TotalRoutes.Set(float64(totalRoutes))
 }

src/code.cloudfoundry.org/gorouter/metrics/metricsreporter_test.go

@@ -99,6 +99,15 @@ var _ = Describe("Metrics", func() {
 			Expect(getMetrics(r.Port())).To(ContainSubstring(`routes_pruned 50`))
 		})
 
+		It("increments the routes added metric", func() {
+			m.CaptureRouteAdded()
+			Expect(getMetrics(r.Port())).To(ContainSubstring(`routes_added 1`))
+		})
+		It("increments the routes deleted metric", func() {
+			m.CaptureRouteDeleted()
+			Expect(getMetrics(r.Port())).To(ContainSubstring(`routes_deleted 1`))
+		})
+
 		Describe("captures route registration latency", func() {
 			It("properly splits the latencies apart", func() {
 				m.CaptureRouteRegistrationLatency(1234 * time.Microsecond)

src/code.cloudfoundry.org/gorouter/metrics_prometheus/metrics.go

@@ -100,6 +100,7 @@ func (r *RouteRegistry) Register(uri route.Uri, endpoint *route.Endpoint) {
 		r.logger.Info("route-registered", slog.Any("uri", uri))
 		// for backward compatibility:
 		r.logger.Debug("uri-added", slog.Any("uri", uri))
+		r.reporter.CaptureRouteAdded()
 	}
 
 	switch poolPutResult {
@@ -197,6 +198,7 @@ func (r *RouteRegistry) Unregister(uri route.Uri, endpoint *route.Endpoint) {
 
 	if routeRemoved {
 		r.logger.Info("route-unregistered", slog.Any("uri", uri))
+		r.reporter.CaptureRouteDeleted()
 	} else {
 		r.logger.Info("route-not-unregistered", slog.Any("uri", uri))
 	}