Expvar metrics support added. Metrics refactored to its own package.

metrics/metrics.go

@@ -0,0 +1,60 @@
+package metrics
+
+import (
+	"github.com/go-kit/kit/metrics"
+	"github.com/go-kit/kit/metrics/discard"
+	"github.com/go-kit/kit/metrics/expvar"
+	"github.com/go-kit/kit/metrics/prometheus"
+	stdprometheus "github.com/prometheus/client_golang/prometheus"
+)
+
+// Type represents metrics Types
+type Type int
+
+const (
+	// Discard discards any metrics.
+	Discard Type = iota
+
+	// Prometheus starts server at :2112 and exports metrics data to /metrics
+	Prometheus
+
+	// ExpVar uses built-in expvar package
+	ExpVar
+)
+
+// Metrics type stores metrics
+type Metrics struct {
+	RequestCounter  metrics.Counter
+	ResponseCounter metrics.Counter
+}
+
+// NewMetrics creates new metrics with given metrics.Type
+func NewMetrics(metricsType Type) *Metrics {
+	switch metricsType {
+	case Discard:
+		return &Metrics{
+			RequestCounter:  discard.NewCounter(),
+			ResponseCounter: discard.NewCounter(),
+		}
+	case ExpVar:
+		return &Metrics{
+			RequestCounter:  expvar.NewCounter("request_count"),
+			ResponseCounter: expvar.NewCounter("response_count"),
+		}
+	case Prometheus:
+		return &Metrics{
+			RequestCounter: prometheus.NewCounterFrom(stdprometheus.CounterOpts{
+				Namespace: "geziyor",
+				Name:      "request_count",
+				Help:      "Request count",
+			}, []string{"method"}),
+			ResponseCounter: prometheus.NewCounterFrom(stdprometheus.CounterOpts{
+				Namespace: "geziyor",
+				Name:      "response_count",
+				Help:      "Response count",
+			}, []string{"method"}),
+		}
+	default:
+		return nil
+	}
+}