Initial commit

wrapper/prometheus/prometheus.go

@@ -0,0 +1,88 @@
+package prometheus
+
+import (
+	"context"
+
+	"github.com/micro/go-micro/server"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	// Namespace defines the namespace of the defined metrics.
+	Namespace = "ocis"
+)
+
+// NewHandlerWrapper initializes the prometheus handler wrapper.
+func NewHandlerWrapper(opts ...server.Option) server.HandlerWrapper {
+	counter := prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: Namespace,
+			Name:      "request_total",
+			Help:      "How many service requests processed",
+		},
+		[]string{"method", "status"},
+	)
+
+	latency := prometheus.NewSummaryVec(
+		prometheus.SummaryOpts{
+			Namespace: Namespace,
+			Name:      "upstream_latency_microseconds",
+			Help:      "Service method latencies in microseconds",
+		},
+		[]string{"method"},
+	)
+
+	duration := prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Namespace: Namespace,
+			Name:      "request_duration_seconds",
+			Help:      "Service method request time in seconds",
+		},
+		[]string{"method"},
+	)
+
+	prometheus.Register(
+		prometheus.NewProcessCollector(prometheus.ProcessCollectorOpts{}),
+	)
+
+	prometheus.Register(
+		prometheus.NewGoCollector(),
+	)
+
+	prometheus.Register(
+		counter,
+	)
+
+	prometheus.Register(
+		latency,
+	)
+
+	prometheus.Register(
+		duration,
+	)
+
+	return func(fn server.HandlerFunc) server.HandlerFunc {
+		return func(ctx context.Context, req server.Request, rsp interface{}) error {
+			name := req.Endpoint()
+
+			timer := prometheus.NewTimer(prometheus.ObserverFunc(func(v float64) {
+				us := v * 1000000
+
+				latency.WithLabelValues(name).Observe(us)
+				duration.WithLabelValues(name).Observe(v)
+			}))
+
+			defer timer.ObserveDuration()
+
+			err := fn(ctx, req, rsp)
+
+			if err == nil {
+				counter.WithLabelValues(name, "success").Inc()
+			} else {
+				counter.WithLabelValues(name, "fail").Inc()
+			}
+
+			return err
+		}
+	}
+}