reverse proxy to intermittently interrupt requests to /_xpack

reverse_proxy.go

package main

import (
	"log"
	"math/rand"
	"net/http"
	"net/http/httputil"
	"net/url"
	"time"
)

func main() {
	rpURL, err := url.Parse("http://localhost:9200")
	if err != nil {
		log.Fatal(err)
	}
	rand.Seed(time.Now().UnixNano())

	rp := httputil.NewSingleHostReverseProxy(rpURL)

	log.Printf("listening on :9201, proxying to %v\n", rpURL)
	log.Fatal(http.ListenAndServe(":9201", wrap(rp)))
}

func wrap(h http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path == "/_xpack" {
			log.Println("hit xpack path")
			if rand.Intn(100) < 40 {
				log.Println("responding with error")
				http.Error(w, `{"error":"whoops"}`, http.StatusInternalServerError)
				return
			}
		}
		h.ServeHTTP(w, r)
	})
}