Extract metrics to own package and refactor implementations

metrics/statsd.go

@@ -0,0 +1,61 @@
+package metrics
+
+import (
+	"time"
+
+	"github.com/containous/traefik/log"
+	"github.com/containous/traefik/safe"
+	"github.com/containous/traefik/types"
+	kitlog "github.com/go-kit/kit/log"
+	"github.com/go-kit/kit/metrics/statsd"
+)
+
+var statsdClient = statsd.New("traefik.", kitlog.LoggerFunc(func(keyvals ...interface{}) error {
+	log.Info(keyvals)
+	return nil
+}))
+
+var statsdTicker *time.Ticker
+
+// RegisterStatsd registers the metrics pusher if this didn't happen yet and creates a statsd Registry instance.
+func RegisterStatsd(config *types.Statsd) Registry {
+	if statsdTicker == nil {
+		statsdTicker = initStatsdTicker(config)
+	}
+
+	return &standardRegistry{
+		enabled:              true,
+		reqsCounter:          statsdClient.NewCounter(ddMetricsReqsName, 1.0),
+		reqDurationHistogram: statsdClient.NewTiming(ddMetricsLatencyName, 1.0),
+		retriesCounter:       statsdClient.NewCounter(ddRetriesTotalName, 1.0),
+	}
+}
+
+// initStatsdTicker initializes metrics pusher and creates a statsdClient if not created already
+func initStatsdTicker(config *types.Statsd) *time.Ticker {
+	address := config.Address
+	if len(address) == 0 {
+		address = "localhost:8125"
+	}
+	pushInterval, err := time.ParseDuration(config.PushInterval)
+	if err != nil {
+		log.Warnf("Unable to parse %s into pushInterval, using 10s as default value", config.PushInterval)
+		pushInterval = 10 * time.Second
+	}
+
+	report := time.NewTicker(pushInterval)
+
+	safe.Go(func() {
+		statsdClient.SendLoop(report.C, "udp", address)
+	})
+
+	return report
+}
+
+// StopStatsd stops internal statsdTicker which controls the pushing of metrics to StatsD Agent and resets it to `nil`
+func StopStatsd() {
+	if statsdTicker != nil {
+		statsdTicker.Stop()
+	}
+	statsdTicker = nil
+}