Support for Metrics and Prometheus.

middlewares/prometheus.go

@@ -0,0 +1,65 @@
+package middlewares
+
+import (
+	"github.com/containous/traefik/types"
+	"github.com/go-kit/kit/metrics"
+	"github.com/go-kit/kit/metrics/prometheus"
+	stdprometheus "github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"net/http"
+)
+
+const (
+	reqsName    = "requests_total"
+	latencyName = "request_duration_milliseconds"
+)
+
+// Prometheus is an Implementation for Metrics that exposes prometheus metrics for the number of requests,
+// the latency and the response size, partitioned by status code and method.
+type Prometheus struct {
+	reqsCounter      metrics.Counter
+	latencyHistogram metrics.Histogram
+}
+
+func (p *Prometheus) getReqsCounter() metrics.Counter {
+	return p.reqsCounter
+}
+
+func (p *Prometheus) getLatencyHistogram() metrics.Histogram {
+	return p.latencyHistogram
+}
+
+// NewPrometheus returns a new prometheus Metrics implementation.
+func NewPrometheus(name string, config *types.Prometheus) *Prometheus {
+	var m Prometheus
+	m.reqsCounter = prometheus.NewCounterFrom(
+		stdprometheus.CounterOpts{
+			Name:        reqsName,
+			Help:        "How many HTTP requests processed, partitioned by status code and method.",
+			ConstLabels: stdprometheus.Labels{"service": name},
+		},
+		[]string{"code", "method"},
+	)
+
+	var buckets []float64
+	if config.Buckets != nil {
+		buckets = config.Buckets
+	} else {
+		buckets = []float64{100, 300, 1200, 5000}
+	}
+
+	m.latencyHistogram = prometheus.NewHistogramFrom(
+		stdprometheus.HistogramOpts{
+			Name:        latencyName,
+			Help:        "How long it took to process the request, partitioned by status code and method.",
+			ConstLabels: stdprometheus.Labels{"service": name},
+			Buckets:     buckets,
+		},
+		[]string{"code", "method"},
+	)
+	return &m
+}
+
+func (p *Prometheus) handler() http.Handler {
+	return promhttp.Handler()
+}