Setup server with external prometheus + CORS allowed

run.go

package main

import (
	"log"
	"net/http"
	"time"

	"github.com/swift-sunshine/swscore/config"
	"github.com/swift-sunshine/swscore/routing"
)

func setupConfig() {
	conf := config.NewConfig()
	conf.PrometheusServiceUrl = "http://prometheus-istio-system.127.0.0.1.nip.io"
	config.Set(conf)
}

// Integration test. Manual for the moment.
func main() {
	setupConfig()
	startServer()
	// Open up your browser and hit http://127.0.0.1:8000/api/namespaces/tutorial/services/preference/metrics
}

func corsAllowed(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Access-Control-Allow-Origin", "*")
		w.Header().Set("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept")
		next.ServeHTTP(w, r)
	})
}

func startServer() {
	conf := config.Get()
	router := routing.NewRouter(conf)
	router.Use(corsAllowed)
	srv := &http.Server{
		Handler:      router,
		Addr:         "127.0.0.1:8000",
		WriteTimeout: 15 * time.Second,
		ReadTimeout:  15 * time.Second,
	}
	log.Fatal(srv.ListenAndServe())
}