// https://github.com/stefanprodan/k8s-podinfo/blob/master/pkg/server/instrument.go

func NewInstrument() *Instrument {
	// used for monitoring and alerting (RED method)
	histogram := prometheus.NewHistogramVec(prometheus.HistogramOpts{
		Subsystem: "http",
		Name:      "requests",
		Help:      "Seconds spent serving HTTP requests.",
		Buckets:   prometheus.DefBuckets,
	}, []string{"method", "path", "status"})
	// used for horizontal pod auto-scaling (Kubernetes HPA v2)
	counter := prometheus.NewCounterVec(
		prometheus.CounterOpts{
			Subsystem: "http",
			Name:      "requests_total",
			Help:      "The total number of HTTP requests.",
		},
		[]string{"status"},
	)

	prometheus.MustRegister(histogram)
	prometheus.MustRegister(counter)

	return &Instrument{
		Histogram: histogram,
		Counter:   counter,
	}
}