Golang multiserver

main.go

package main

import (
	"context"
	"fmt"
	"net/http"
)

func shutdown(ready chan bool) func(http.ResponseWriter, *http.Request) {
	return func(w http.ResponseWriter, r *http.Request) {
		ready <- false
		w.WriteHead(http.StatusOK)
		w.Write("Shutting down")
	}
}

func health(ready chan bool) func(http.ResponseWriter, *http.Request) {
	return func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		w.Write(fmt.Sprintf("Ready: %v", <-ready))
	}
}

func main() {
	mainServer := http.Server{Addr: ":8080", Handler: http.Handler(shutdown(ready))}
	healthServer := http.Server{Addr: ":9000", Handler: health(ready)}
	ready := make(chan bool)

	go func() {
		healthServer.ListenAndServe()
	}()

	go func() {
		ready <- true
		mainServer.ListenAndServe()
	}()

	select {
	case r := <-ready:
		if !r {
			mainServer.Shutdown(context.Background())
			healthServer.Shutdown(context.Background())
		}
	}
}