package metrics import ( "context" "fmt" "net/http" "contrib.go.opencensus.io/exporter/prometheus" "github.com/waku-org/go-waku/waku/v2/metrics" "go.opencensus.io/plugin/ochttp" "go.opencensus.io/plugin/runmetrics" "go.opencensus.io/stats/view" "go.uber.org/zap" ) // Server runs and controls a HTTP pprof interface. type Server struct { server *http.Server log *zap.Logger } // NewMetricsServer creates a prometheus server on a particular interface and port func NewMetricsServer(address string, port int, log *zap.Logger) *Server { p := Server{ log: log.Named("metrics"), } _ = runmetrics.Enable(runmetrics.RunMetricOptions{ EnableCPU: true, EnableMemory: true, }) pe, err := prometheus.NewExporter(prometheus.Options{}) if err != nil { p.log.Fatal("creating Prometheus stats exporter", zap.Error(err)) } view.RegisterExporter(pe) p.log.Info("starting server", zap.String("address", address), zap.Int("port", port)) mux := http.NewServeMux() mux.Handle("/metrics", pe) // Healthcheck mux.HandleFunc("/health", func(w http.ResponseWriter, r *http.Request) { fmt.Fprint(w, "OK") }) h := &ochttp.Handler{Handler: mux} // Register the views if err := view.Register( metrics.MessageView, metrics.StoreMessagesView, metrics.FilterSubscriptionsView, metrics.StoreErrorTypesView, metrics.LightpushErrorTypesView, metrics.StoreMessagesView, metrics.PeersView, metrics.DialsView, metrics.VersionView, ); err != nil { p.log.Fatal("registering views", zap.Error(err)) } p.server = &http.Server{ Addr: fmt.Sprintf("%s:%d", address, port), Handler: h, } return &p } // Start executes the HTTP server in the background. func (p *Server) Start() { p.log.Info("server stopped ", zap.Error(p.server.ListenAndServe())) } // Stop shuts down the prometheus server func (p *Server) Stop(ctx context.Context) error { err := p.server.Shutdown(ctx) if err != nil { p.log.Error("stopping server", zap.Error(err)) return err } return nil }