Function instrumentRoundTripper

tutorials/whatsup/reference/main.go:283–319

(reg prometheus.Registerer, clientName string, rt http.RoundTripper)

}

func instrumentRoundTripper(reg prometheus.Registerer, clientName string, rt http.RoundTripper) http.RoundTripper {
	reg = prometheus.WrapRegistererWith(prometheus.Labels{"client": clientName}, reg)

	requestDuration := promauto.With(reg).NewHistogramVec(
		prometheus.HistogramOpts{
			Name:    "http_client_request_duration_seconds",
			Help:    "Tracks the latencies for HTTP requests.",
			Buckets: []float64{0.1, 0.3, 0.6, 1, 3, 6, 9, 20},
		},
		[]string{"method", "code"},
	)
	requestsTotal := promauto.With(reg).NewCounterVec(
		prometheus.CounterOpts{
			Name: "http_client_requests_total",
			Help: "Tracks the number of HTTP requests.",
		}, []string{"method", "code"},
	)
	responseInflight := promauto.With(reg).NewGauge(
		prometheus.GaugeOpts{
			Name: "http_client_requests_inflight",
			Help: "Tracks the number of client requests currently in progress.",
		},
	)

	var base http.RoundTripper
	base = promhttp.InstrumentRoundTripperCounter(
		requestsTotal,
		promhttp.InstrumentRoundTripperInFlight(
			responseInflight,
			promhttp.InstrumentRoundTripperDuration(requestDuration, rt, promhttp.WithExemplarFromContext(getExemplarFn)),
		),
		promhttp.WithExemplarFromContext(getExemplarFn),
	)

	// Wrap with tracing. This will be visited as a first middleware.
	return tracinghttp.NewTripperware().WrapRoundTipper(clientName, base)
}