addr := flag.String("http-address", ":8080", "HTTP server listen address.") zaprObserver := zaprprom.NewObserver() zaprOptions := zapr.RegisterFlags(flag.CommandLine, zapr.AllOptions( zapr.WithObserver(zaprObserver), zapr.WithLevel(2), // Override default logging level. )...) flag.Parse() log, sink := zapr.NewLogger(zaprOptions...) defer sink.Flush() // For most GOOS (linux and darwin), flushing to stderr is a no-op. log.Info("Hello, zap logr with option flags!") reg := prometheus.NewRegistry() reg.MustRegister( collectors.NewGoCollector(), collectors.NewBuildInfoCollector(), collectors.NewProcessCollector(collectors.ProcessCollectorOpts{}), zaprObserver, // Register Observer with Prometheus. ) log.Info("Hello, zap logr Prometheus metrics!") mux := http.NewServeMux() mux.Handle("/metrics", promhttp.HandlerFor(reg, promhttp.HandlerOpts{})) srv := http.Server{ Addr: *addr, Handler: mux, ErrorLog: zapr.NewStdErrorLogger(sink), // Adapt LogSink to stdlib *log.Logger. } if err := srv.ListenAndServe(); err != nil { log.Error(err, "Failed to serve HTTP") }