Initial commit

internal/service/monitoring/config/metrics.go

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) New Cloud Technologies, Ltd., 2013-2026
+ *
+ * You can not use the contents of the file in any way without New Cloud Technologies Ltd. written permission.
+ * To obtain such a permit, you should contact New Cloud Technologies, Ltd. at https://myoffice.ru/contacts/
+ */
+
+package config
+
+import (
+	"reflect"
+	"strconv"
+	"strings"
+
+	"github.com/go-viper/mapstructure/v2"
+)
+
+type CommaSeparatedFloat64Slice []float64
+
+func CommaSeparatedFloat64SliceHookFunc() mapstructure.DecodeHookFuncType {
+	return func(
+		f reflect.Type,
+		t reflect.Type,
+		data interface{},
+	) (interface{}, error) {
+		// Check that the data is string
+		if f.Kind() != reflect.String {
+			return data, nil
+		}
+
+		// Check that the target type is our custom type
+		if t != reflect.TypeOf(CommaSeparatedFloat64Slice{}) {
+			return data, nil
+		}
+
+		stringSlice := strings.Split(data.(string), ",")
+		floatSlice := make([]float64, 0)
+		for _, str := range stringSlice {
+			val, err := strconv.ParseFloat(strings.TrimSpace(str), 64)
+			if err != nil {
+				return nil, err
+			}
+			floatSlice = append(floatSlice, val)
+		}
+
+		// Return the parsed value
+		return CommaSeparatedFloat64Slice(floatSlice), nil
+	}
+}
+
+// HttpMetrics configuration properties for http monitoring
+type HttpMetrics struct {
+	HistogramEnabled bool
+	Buckets          CommaSeparatedFloat64Slice
+}
+
+// Metrics configuration properties for monitoring
+type Metrics struct {
+	Endpoint         string
+	HistogramBuckets CommaSeparatedFloat64Slice
+	Http             HttpMetrics
+}

internal/service/monitoring/metrics.go

@@ -0,0 +1,95 @@
+package monitoring
+
+import (
+	"net/http"
+	"strconv"
+	"time"
+
+	"github.com/gorilla/mux"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+
+	"payouts/internal/service/monitoring/config"
+)
+
+const (
+	METRICS_NAMESPACE = "payouts"
+)
+
+// Metrics represents the metrics service
+type Metrics interface {
+	GetMiddleware() func(next http.Handler) http.Handler
+}
+
+// metrics represents the metrics service implementation
+type metrics struct {
+	httpDuration prometheus.ObserverVec
+}
+
+// NewMetrics instantiates metrics service
+func NewMetrics(config config.Metrics) (Metrics, error) {
+	var httpDuration prometheus.ObserverVec
+	if config.Http.HistogramEnabled {
+		httpDuration = CreateHttpHistogram(config.Http.Buckets)
+	} else {
+		httpDuration = CreateHttpSummary(config.Http.Buckets)
+
+	}
+	return &metrics{
+		httpDuration: httpDuration,
+	}, nil
+}
+
+// GetMiddleware returns the middleware to be used in mux router
+func (m *metrics) GetMiddleware() func(next http.Handler) http.Handler {
+	return GetMiddleware(m.httpDuration)
+}
+
+func CreateHttpSummary(buckets []float64) *prometheus.SummaryVec {
+	return promauto.NewSummaryVec(prometheus.SummaryOpts{
+		Name: "http_server_requests_seconds",
+		Help: "Duration of HTTP requests.",
+	}, []string{"uri", "method", "code"})
+}
+
+func CreateHttpHistogram(buckets []float64) *prometheus.HistogramVec {
+	return promauto.NewHistogramVec(prometheus.HistogramOpts{
+		Name:    "http_server_requests_seconds",
+		Help:    "Duration of HTTP requests.",
+		Buckets: buckets,
+	}, []string{"uri", "method", "code"})
+
+}
+
+func GetMiddleware(histogramVec prometheus.ObserverVec) func(next http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			route := mux.CurrentRoute(r)
+			path, _ := route.GetPathTemplate()
+			wd := &writerDelegate{
+				ResponseWriter: w,
+				statusCode:     http.StatusOK,
+			}
+
+			start := time.Now()
+			defer func() {
+				duration := time.Since(start).Seconds()
+				code := strconv.Itoa(wd.statusCode)
+				histogramVec.WithLabelValues(path, r.Method, code).Observe(duration)
+			}()
+
+			next.ServeHTTP(wd, r)
+		})
+	}
+}
+
+type writerDelegate struct {
+	http.ResponseWriter
+	statusCode int
+}
+
+// override the WriteHeader method
+func (w *writerDelegate) WriteHeader(statusCode int) {
+	w.statusCode = statusCode
+	w.ResponseWriter.WriteHeader(statusCode)
+}

internal/service/monitoring/module.go

@@ -0,0 +1,24 @@
+package monitoring
+
+import (
+	"go.uber.org/fx"
+
+	"payouts/internal/config"
+)
+
+// Module is a fx module
+var Module = fx.Options(
+	fx.Provide(New),
+)
+
+// Params represents the module input params
+type Params struct {
+	fx.In
+
+	AppConfig *config.App
+}
+
+// New instantiates the metrics service
+func New(p Params) (Metrics, error) {
+	return NewMetrics(p.AppConfig.Metrics)
+}