package metrics import ( "fmt" "net/http" "github.com/ethereum/go-ethereum/log" "github.com/ethereum/go-ethereum/metrics" gethprom "github.com/ethereum/go-ethereum/metrics/prometheus" prom "github.com/prometheus/client_golang/prometheus" "github.com/prometheus/client_golang/prometheus/promhttp" ) // Server runs and controls a HTTP pprof interface. type Server struct { server *http.Server } func NewMetricsServer(port int, r metrics.Registry) *Server { mux := http.NewServeMux() mux.Handle("/health", healthHandler()) mux.Handle("/metrics", Handler(r)) p := Server{ server: &http.Server{ Addr: fmt.Sprintf(":%d", port), Handler: mux, }, } return &p } func healthHandler() http.Handler { return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { _, err := w.Write([]byte("OK")) if err != nil { log.Error("health handler error", "err", err) } }) } func Handler(reg metrics.Registry) http.Handler { // we disable compression because geth doesn't support it opts := promhttp.HandlerOpts{DisableCompression: true} // we are combining handlers to avoid having 2 endpoints statusMetrics := promhttp.HandlerFor(prom.DefaultGatherer, opts) // our metrics gethMetrics := gethprom.Handler(reg) // geth metrics return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { statusMetrics.ServeHTTP(w, r) gethMetrics.ServeHTTP(w, r) }) } // Listen starts the HTTP server in the background. func (p *Server) Listen() { log.Info("metrics server stopped", "err", p.server.ListenAndServe()) }