add metrics for service

pkg/metrics/metrics.go

@@ -0,0 +1,95 @@
+package metrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	global = newMetrics()
+)
+
+type Metrics struct {
+	services           prometheus.Gauge
+	requests           *prometheus.CounterVec
+	requestsInFlight   *prometheus.GaugeVec
+	requestSeconds     *prometheus.HistogramVec
+	requestInputBytes  *prometheus.CounterVec
+	requestOutputBytes *prometheus.CounterVec
+}
+
+func newMetrics() *Metrics {
+	m := &Metrics{
+		services: prometheus.NewGauge(
+			prometheus.GaugeOpts{
+				Name: "gost_services",
+				Help: "Current number of services",
+			}),
+
+		requests: prometheus.NewCounterVec(
+			prometheus.CounterOpts{
+				Name: "gost_service_requests_total",
+				Help: "Total number of requests",
+			},
+			[]string{"service"}),
+
+		requestsInFlight: prometheus.NewGaugeVec(
+			prometheus.GaugeOpts{
+				Name: "gost_service_requests_in_flight",
+				Help: "Current in-flight requests",
+			},
+			[]string{"service"}),
+
+		requestSeconds: prometheus.NewHistogramVec(
+			prometheus.HistogramOpts{
+				Name: "gost_service_request_duration_seconds",
+				Help: "Distribution of request latencies",
+				Buckets: []float64{
+					.005, .01, .025, .05, .1, .25, .5, 1, 2.5, 5, 10, 15, 20, 30,
+				},
+			},
+			[]string{"service"}),
+		requestInputBytes: prometheus.NewCounterVec(
+			prometheus.CounterOpts{
+				Name: "gost_service_request_transfer_input_bytes_total",
+				Help: "Total request input data transfer size in bytes",
+			},
+			[]string{"service"}),
+		requestOutputBytes: prometheus.NewCounterVec(
+			prometheus.CounterOpts{
+				Name: "gost_service_request_transfer_output_bytes_total",
+				Help: "Total request output data transfer size in bytes",
+			},
+			[]string{"service"}),
+	}
+	prometheus.MustRegister(m.services)
+	prometheus.MustRegister(m.requests)
+	prometheus.MustRegister(m.requestsInFlight)
+	prometheus.MustRegister(m.requestSeconds)
+	prometheus.MustRegister(m.requestInputBytes)
+	prometheus.MustRegister(m.requestOutputBytes)
+	return m
+}
+
+func Services() prometheus.Gauge {
+	return global.services
+}
+
+func Requests(service string) prometheus.Counter {
+	return global.requests.With(prometheus.Labels{"service": service})
+}
+
+func RequestsInFlight(service string) prometheus.Gauge {
+	return global.requestsInFlight.With(prometheus.Labels{"service": service})
+}
+
+func RequestSeconds(service string) prometheus.Observer {
+	return global.requestSeconds.With(prometheus.Labels{"service": service})
+}
+
+func RequestInputBytes(service string) prometheus.Counter {
+	return global.requestInputBytes.With(prometheus.Labels{"service": service})
+}
+
+func RequestOutputBytes(service string) prometheus.Counter {
+	return global.requestOutputBytes.With(prometheus.Labels{"service": service})
+}