feat: enable prometheus metrics endpoint

Author: kelein

govoyage/Dockerfile

@@ -0,0 +1,18 @@
+FROM golang:1.23-alpine AS builder
+RUN apk add -U tzdata
+RUN apk --update add ca-certificates
+WORKDIR /app
+COPY . .
+COPY ../go.* .
+RUN go mod tidy
+RUN make app-linux
+
+
+FROM scratch
+COPY --from=builder /usr/share/zoneinfo /usr/share/zoneinfo
+COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
+COPY --from=builder /etc/passwd /etc/passwd
+COPY --from=builder /etc/group /etc/group
+COPY --from=builder /app/bin/govoyage-server .
+EXPOSE 8080 8090
+CMD ["/govoyage-server"]

govoyage/cmd/server/server.go

@@ -15,6 +15,7 @@ import (
 
 	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/swaggest/swgui/v5emb"
 	clientv3 "go.etcd.io/etcd/client/v3"
 	"go.etcd.io/etcd/server/v3/proxy/grpcproxy"
@@ -190,6 +191,9 @@ func registerService(addr string) error {
 func runHTTPServer() *http.ServeMux {
 	mux := http.NewServeMux()
 
+	// * Register metrics endpoint
+	mux.Handle("/metrics", promhttp.Handler())
+
 	// * Register index handler
 	mux.HandleFunc("/index", func(w http.ResponseWriter, r *http.Request) {
 		w.Write([]byte(index))