country-geo-locations/internal/exporter/middleware.go

package exporter

import (
	"net/http"

	"github.com/prometheus/client_golang/prometheus"
)

type Middleware struct {
	metrics *Metrics
}

func (m Middleware) handler(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		timer := prometheus.NewTimer(m.metrics.metricRequestLatency)
		next.ServeHTTP(w, r)
		m.metrics.metricRequestsTotal.Inc()
		timer.ObserveDuration()
	})
}