promethues histograms with negative bounds

histogram.go

package main

import (
	"fmt"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"io/ioutil"
	"log"
	"math/rand"
	"net/http"
	"time"
)

func main() {
	rand.Seed(time.Now().Unix())
	http.Handle("/metrics", promhttp.Handler())
	histogram := prometheus.NewHistogram(
		prometheus.HistogramOpts{
			Namespace: "foo",
			Name:      "bar",
			Help:      "This is my histogram with negative bounds",
			Buckets: []float64{-10,-5,0,5,10},
		})
	prometheus.MustRegister(histogram)
	go func() {
		for {
			histogram.Observe(rand.NormFloat64()*100)
			time.Sleep(time.Millisecond)
		}
	}()
	
	go func() {
		for {
			time.Sleep(10*time.Second)
			resp, _ := http.Get("http://127.0.0.1:40800/metrics")
			data, _ := ioutil.ReadAll(resp.Body)
			fmt.Println(string(data))
			//os.Exit(0)
		}
	}()

	log.Fatal(http.ListenAndServe("127.0.0.1:40800", nil))
}