service backend

api/billing/fees/internal/service/fees/metrics.go

@@ -0,0 +1,71 @@
+package fees
+
+import (
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+	feesv1 "github.com/tech/sendico/pkg/proto/billing/fees/v1"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+var (
+	metricsOnce sync.Once
+
+	quoteRequestsTotal *prometheus.CounterVec
+	quoteLatency       *prometheus.HistogramVec
+)
+
+func initMetrics() {
+	metricsOnce.Do(func() {
+		quoteRequestsTotal = promauto.NewCounterVec(
+			prometheus.CounterOpts{
+				Namespace: "billing",
+				Subsystem: "fees",
+				Name:      "requests_total",
+				Help:      "Total number of fee service requests processed.",
+			},
+			[]string{"call", "trigger", "status", "fx_used"},
+		)
+
+		quoteLatency = promauto.NewHistogramVec(
+			prometheus.HistogramOpts{
+				Namespace: "billing",
+				Subsystem: "fees",
+				Name:      "request_latency_seconds",
+				Help:      "Latency of fee service requests.",
+				Buckets:   prometheus.DefBuckets,
+			},
+			[]string{"call", "trigger", "status", "fx_used"},
+		)
+	})
+}
+
+func observeMetrics(call string, trigger feesv1.Trigger, statusLabel string, fxUsed bool, took time.Duration) {
+	triggerLabel := trigger.String()
+	if trigger == feesv1.Trigger_TRIGGER_UNSPECIFIED {
+		triggerLabel = "TRIGGER_UNSPECIFIED"
+	}
+	fxLabel := strconv.FormatBool(fxUsed)
+	quoteRequestsTotal.WithLabelValues(call, triggerLabel, statusLabel, fxLabel).Inc()
+	quoteLatency.WithLabelValues(call, triggerLabel, statusLabel, fxLabel).Observe(took.Seconds())
+}
+
+func statusFromError(err error) string {
+	if err == nil {
+		return "success"
+	}
+	st, ok := status.FromError(err)
+	if !ok {
+		return "error"
+	}
+	code := st.Code()
+	if code == codes.OK {
+		return "success"
+	}
+	return strings.ToLower(code.String())
+}