add victoria metrics monitoring wrapper

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

victoriametrics.go

@@ -0,0 +1,82 @@
+package victoriametrics
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"time"
+
+	metrics "github.com/VictoriaMetrics/metrics"
+	"github.com/micro/go-micro/server"
+)
+
+var (
+	defaultMetricPrefix = "micro"
+	metaLabels          []string
+)
+
+func getName(name string, md map[string]interface{}) string {
+	labels := make([]string, 0, len(metaLabels)+len(md))
+	labels = append(labels, metaLabels...)
+
+	for k, v := range md {
+		labels = append(labels, fmt.Sprintf(`%s="%v"`, k, v))
+	}
+
+	if len(labels) > 0 {
+		return fmt.Sprintf(`%s_%s{%s}`, defaultMetricPrefix, name, strings.Join(labels, ","))
+	}
+	return fmt.Sprintf(`%s_%s`, defaultMetricPrefix, name)
+}
+
+func NewHandlerWrapper(opts ...server.Option) server.HandlerWrapper {
+	sopts := server.Options{}
+
+	for _, opt := range opts {
+		opt(&sopts)
+	}
+
+	metadata := make(map[string]string, len(sopts.Metadata))
+	for k, v := range sopts.Metadata {
+		metadata[fmt.Sprintf("%s_%s", defaultMetricPrefix, k)] = v
+	}
+	if len(sopts.Name) > 0 {
+		metadata[fmt.Sprintf("%s_%s", defaultMetricPrefix, "name")] = sopts.Name
+	}
+	if len(sopts.Id) > 0 {
+		metadata[fmt.Sprintf("%s_%s", defaultMetricPrefix, "id")] = sopts.Id
+	}
+	if len(sopts.Version) > 0 {
+		metadata[fmt.Sprintf("%s_%s", defaultMetricPrefix, "version")] = sopts.Version
+	}
+	metaLabels = make([]string, 0, len(metadata))
+	for k, v := range metadata {
+		metaLabels = append(metaLabels, fmt.Sprintf(`%s="%v"`, k, v))
+	}
+
+	return func(fn server.HandlerFunc) server.HandlerFunc {
+		return func(ctx context.Context, req server.Request, rsp interface{}) error {
+			name := req.Endpoint()
+			timeCounterSummary := metrics.GetOrCreateSummary(
+				getName("upstream_latency_seconds", map[string]interface{}{"method": name}),
+			)
+			timeCounterHistogram := metrics.GetOrCreateSummary(
+				getName("request_duration_seconds", map[string]interface{}{"method": name}),
+			)
+
+			ts := time.Now()
+			err := fn(ctx, req, rsp)
+			te := time.Since(ts)
+
+			timeCounterSummary.Update(float64(te.Seconds()))
+			timeCounterHistogram.Update(te.Seconds())
+			if err == nil {
+				metrics.GetOrCreateCounter(getName("request_total", map[string]interface{}{"method": name, "status": "success"})).Inc()
+			} else {
+				metrics.GetOrCreateCounter(getName("request_total", map[string]interface{}{"method": name, "status": "failure"})).Inc()
+			}
+
+			return err
+		}
+	}
+}