Initial QSfera import

Server/services/proxy/pkg/middleware/metrics.go

@@ -0,0 +1,28 @@
+package middleware
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/go-chi/chi/v5/middleware"
+	"github.com/qsfera/server/services/proxy/pkg/metrics"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+// Instrumenter provides a middleware to create metrics
+func Instrumenter(m metrics.Metrics) func(next http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			start := time.Now()
+			ww := middleware.NewWrapResponseWriter(w, r.ProtoMajor)
+			m.Requests.With(prometheus.Labels{"method": r.Method}).Inc()
+
+			next.ServeHTTP(ww, r)
+
+			m.Duration.With(prometheus.Labels{"method": r.Method}).Observe(float64(time.Since(start).Seconds()))
+			if ww.Status() >= 500 {
+				m.Errors.With(prometheus.Labels{"method": r.Method}).Inc()
+			}
+		})
+	}
+}