DataDog and StatsD Metrics Support

* Added support for DataDog and StatsD monitoring
* Added documentation

server/configuration.go

@@ -437,6 +437,14 @@ func NewTraefikDefaultPointersConfiguration() *TraefikConfiguration {
 		Prometheus: &types.Prometheus{
 			Buckets: types.Buckets{0.1, 0.3, 1.2, 5},
 		},
+		Datadog: &types.Datadog{
+			Address:      "localhost:8125",
+			PushInterval: "10s",
+		},
+		StatsD: &types.Statsd{
+			Address:      "localhost:8125",
+			PushInterval: "10s",
+		},
 	}
 
 	// default Marathon

server/server.go

@@ -157,6 +157,7 @@ func (server *Server) Close() {
 			os.Exit(1)
 		}
 	}(ctx)
+	stopMetricsClients(server.globalConfiguration)
 	server.stopLeadership()
 	server.routinesPool.Cleanup()
 	close(server.configurationChan)
@@ -198,6 +199,7 @@ func (server *Server) setupServerEntryPoint(newServerEntryPointName string, newS
 	if server.accessLoggerMiddleware != nil {
 		serverMiddlewares = append(serverMiddlewares, server.accessLoggerMiddleware)
 	}
+	initializeMetricsClients(server.globalConfiguration)
 	metrics := newMetrics(server.globalConfiguration, newServerEntryPointName)
 	if metrics != nil {
 		serverMiddlewares = append(serverMiddlewares, middlewares.NewMetricsWrapper(metrics))
@@ -1060,18 +1062,52 @@ func (*Server) configureBackends(backends map[string]*types.Backend) {
 // Note that given there is no metrics instrumentation configured, it will return nil.
 func newMetrics(globalConfig GlobalConfiguration, name string) middlewares.Metrics {
 	metricsEnabled := globalConfig.Web != nil && globalConfig.Web.Metrics != nil
-	if metricsEnabled && globalConfig.Web.Metrics.Prometheus != nil {
-		metrics, _, err := middlewares.NewPrometheus(name, globalConfig.Web.Metrics.Prometheus)
-		if err != nil {
-			log.Errorf("Error creating Prometheus Metrics implementation: %s", err)
-			return nil
+	if metricsEnabled {
+		// Create MultiMetric
+		metrics := []middlewares.Metrics{}
+
+		if globalConfig.Web.Metrics.Prometheus != nil {
+			metric, _, err := middlewares.NewPrometheus(name, globalConfig.Web.Metrics.Prometheus)
+			if err != nil {
+				log.Errorf("Error creating Prometheus metrics implementation: %s", err)
+			}
+			log.Debug("Configured Prometheus metrics")
+			metrics = append(metrics, metric)
 		}
-		return metrics
+		if globalConfig.Web.Metrics.Datadog != nil {
+			metric := middlewares.NewDataDog(name)
+			log.Debugf("Configured DataDog metrics pushing to %s once every %s", globalConfig.Web.Metrics.Datadog.Address, globalConfig.Web.Metrics.Datadog.PushInterval)
+			metrics = append(metrics, metric)
+		}
+		if globalConfig.Web.Metrics.StatsD != nil {
+			metric := middlewares.NewStatsD(name)
+			log.Debugf("Configured StatsD metrics pushing to %s once every %s", globalConfig.Web.Metrics.StatsD.Address, globalConfig.Web.Metrics.StatsD.PushInterval)
+			metrics = append(metrics, metric)
+		}
+
+		return middlewares.NewMultiMetrics(metrics)
 	}
 
 	return nil
 }
 
+func initializeMetricsClients(globalConfig GlobalConfiguration) {
+	metricsEnabled := globalConfig.Web != nil && globalConfig.Web.Metrics != nil
+	if metricsEnabled {
+		if globalConfig.Web.Metrics.Datadog != nil {
+			middlewares.InitDatadogClient(globalConfig.Web.Metrics.Datadog)
+		}
+		if globalConfig.Web.Metrics.StatsD != nil {
+			middlewares.InitStatsdClient(globalConfig.Web.Metrics.StatsD)
+		}
+	}
+}
+
+func stopMetricsClients(globalConfig GlobalConfiguration) {
+	middlewares.StopDatadogClient()
+	middlewares.StopStatsdClient()
+}
+
 func registerRetryMiddleware(
 	httpHandler http.Handler,
 	globalConfig GlobalConfiguration,

server/server_test.go

@@ -443,8 +443,8 @@ func TestNewMetrics(t *testing.T) {
 
 			metricsImpl := newMetrics(tc.globalConfig, "test1")
 			if metricsImpl != nil {
-				if _, ok := metricsImpl.(*middlewares.Prometheus); !ok {
-					t.Errorf("invalid metricsImpl type, got %T want %T", metricsImpl, &middlewares.Prometheus{})
+				if _, ok := metricsImpl.(*middlewares.MultiMetrics); !ok {
+					t.Errorf("invalid metricsImpl type, got %T want %T", metricsImpl, &middlewares.MultiMetrics{})
 				}
 			}
 		})