Update

.gitea/workflows/demo.yaml

@@ -21,6 +21,11 @@ jobs:
           go-version: "1.25.4"
           cache: true
 
+      - name: Build and test application
+        run: |
+          go mod tidy
+          go build -o ./bin/metrics ./cmd
+
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 

cmd/main.go

@@ -0,0 +1,95 @@
+package main
+
+import (
+	"context"
+	"log"
+	"net/http"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"github.com/VictoriaMetrics/metrics"
+)
+
+// Register various metrics.
+// Metric name may contain labels in Prometheus format - see below.
+var (
+	// Register counter without labels.
+	// requestsTotal = metrics.NewCounter("requests_total")
+
+	requestsTotal = metrics.GetOrCreateCounter("requests_total")
+
+	// Register summary with a single label.
+	requestDuration = metrics.NewSummary(`requests_duration_seconds{path="/foobar/baz"}`)
+
+	// Register gauge with two labels.
+	// queueSize = metrics.NewGauge(`queue_size{queue="foobar",topic="baz"}`, func() float64 {
+	// 	return float64(foobarQueue.Len())
+	// })
+
+	// Register histogram with a single label.
+	// responseSize = metrics.NewHistogram(`response_size{path="/foo/bar"}`)
+)
+
+func main() {
+	metrics.ExposeMetadata(true)
+
+	http.HandleFunc("/", Recovery(Metrics(rootHandler)))
+
+	// Expose the registered metrics at `/metrics` path.
+	http.HandleFunc("/metrics", Recovery(metricsHandler))
+
+	http.HandleFunc("/hello", Recovery(Metrics(helloHandler)))
+
+	go func() {
+		if err := http.ListenAndServe(":8080", nil); err != nil {
+			log.Fatalln(err)
+		}
+	}()
+
+	ctx, cancel := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
+	defer cancel()
+
+	<-ctx.Done()
+
+}
+
+func rootHandler(w http.ResponseWriter, req *http.Request) {
+	w.Write([]byte("Simple GoLang metrics service"))
+}
+
+// metricsHandler ...
+func metricsHandler(w http.ResponseWriter, req *http.Request) {
+	metrics.WritePrometheus(w, true)
+}
+
+// helloHandler ...
+func helloHandler(w http.ResponseWriter, req *http.Request) {
+	w.Write([]byte("Hello!"))
+}
+
+// Metrics ...
+func Metrics(h http.HandlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		requestsTotal.Inc()
+
+		startTime := time.Now()
+
+		h(w, r)
+
+		requestDuration.UpdateDuration(startTime)
+	}
+}
+
+// Recovery ...
+func Recovery(h http.HandlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		defer func() {
+			if err := recover(); err != nil {
+				log.Println(err)
+			}
+		}()
+
+		h(w, r)
+	}
+}

go.mod

@@ -0,0 +1,11 @@
+module kube-vm
+
+go 1.25.4
+
+require github.com/VictoriaMetrics/metrics v1.40.2
+
+require (
+	github.com/valyala/fastrand v1.1.0 // indirect
+	github.com/valyala/histogram v1.2.0 // indirect
+	golang.org/x/sys v0.15.0 // indirect
+)