64 lines
1.3 KiB
Go
64 lines
1.3 KiB
Go
package main
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import (
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"context"
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"log"
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"math/rand"
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"net/http"
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"os"
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"os/signal"
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"syscall"
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"time"
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"github.com/prometheus/client_golang/prometheus"
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"github.com/prometheus/client_golang/prometheus/promhttp"
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)
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var counter = prometheus.NewCounterVec(
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prometheus.CounterOpts{
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Name: "random_counter_total",
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Help: "A counter that increments randomly from 1 to 30 seconds",
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},
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[]string{},
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)
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func main() {
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// Register Prometheus metrics
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prometheus.MustRegister(counter)
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// Set up HTTP server
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http.Handle("/metrics", promhttp.Handler())
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server := &http.Server{Addr: ":8080"}
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ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
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defer stop()
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go startCounting(ctx)
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go func() {
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log.Println("Starting server on :8080")
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if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
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log.Fatalf("Server error: %v", err)
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}
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}()
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<-ctx.Done()
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log.Println("Shutdown the server")
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// Give one more second for gracefully shutdown
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ctx, cancel := context.WithTimeout(context.Background(), time.Second)
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defer cancel()
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server.Shutdown(ctx)
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}
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func startCounting(ctx context.Context) {
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for {
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select {
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case <-ctx.Done():
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return
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default:
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counter.WithLabelValues().Add(1)
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sleepDuration := time.Duration(rand.Intn(29) + 1)
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time.Sleep(sleepDuration * time.Second)
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}
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}
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}
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