assign service metadata to labels

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

prometheus.go

@@ -2,23 +2,51 @@ package prometheus
 
 import (
 	"context"
+	"fmt"
+
 	"github.com/micro/go-micro/server"
 	"github.com/prometheus/client_golang/prometheus"
 )
 
-func NewHandlerWrapper() server.HandlerWrapper {
+var (
+	defaultMetricPrefix = "micro"
+)
+
+func NewHandlerWrapper(opts ...server.Option) server.HandlerWrapper {
+	md := make(map[string]string)
+	sopts := server.Options{}
+
+	for _, opt := range opts {
+		opt(&sopts)
+	}
+
+	for k, v := range sopts.Metadata {
+		md[fmt.Sprintf("%s_%s", defaultMetricPrefix, k)] = v
+	}
+	if len(sopts.Name) > 0 {
+		md[fmt.Sprintf("%s_%s", defaultMetricPrefix, "name")] = sopts.Name
+	}
+	if len(sopts.Id) > 0 {
+		md[fmt.Sprintf("%s_%s", defaultMetricPrefix, "id")] = sopts.Id
+	}
+	if len(sopts.Version) > 0 {
+		md[fmt.Sprintf("%s_%s", defaultMetricPrefix, "version")] = sopts.Version
+	}
+
 	opsCounter := prometheus.NewCounterVec(
 		prometheus.CounterOpts{
-			Name: "micro_request_total",
-			Help: "How many go-micro requests processed, partitioned by method and status",
+			Name:        fmt.Sprintf("%s_request_total", defaultMetricPrefix),
+			Help:        "How many go-micro requests processed, partitioned by method and status",
+			ConstLabels: md,
 		},
 		[]string{"method", "status"},
 	)
 
 	timeCounter := prometheus.NewSummaryVec(
 		prometheus.SummaryOpts{
-			Name: "micro_request_duration_microseconds",
-			Help: "Service method request latencies in microseconds",
+			Name:        fmt.Sprintf("%s_request_duration_microseconds", defaultMetricPrefix),
+			Help:        "Service method request latencies in microseconds",
+			ConstLabels: md,
 		},
 		[]string{"method"},
 	)