add prometheus instrumentation

server/handler/metrics.go

@@ -0,0 +1,17 @@
+package handler
+
+import (
+	"net/http"
+	"vctp/internal/metrics"
+)
+
+// Metrics exposes Prometheus metrics.
+// @Summary Prometheus metrics
+// @Description Exposes Prometheus metrics for vctp.
+// @Tags metrics
+// @Produce plain
+// @Success 200 "Prometheus metrics"
+// @Router /metrics [get]
+func (h *Handler) Metrics(w http.ResponseWriter, r *http.Request) {
+	metrics.Handler().ServeHTTP(w, r)
+}

server/router/router.go

@@ -65,6 +65,7 @@ func New(logger *slog.Logger, database db.Database, buildTime string, sha1ver st
 	mux.HandleFunc("/api/snapshots/aggregate", h.SnapshotAggregateForce)
 	mux.HandleFunc("/api/snapshots/migrate", h.SnapshotMigrate)
 	mux.HandleFunc("/api/snapshots/regenerate-hourly-reports", h.SnapshotRegenerateHourlyReports)
+	mux.HandleFunc("/metrics", h.Metrics)
 
 	mux.HandleFunc("/snapshots/hourly", h.SnapshotHourlyList)
 	mux.HandleFunc("/snapshots/daily", h.SnapshotDailyList)