Minimal multi-http server example with cancellation

main.go

package main

import (
	"context"
	"fmt"
	"net"
	"net/http"
	"os"
	"os/signal"
	"syscall"
)

func main() {
	ctx, cancel := context.WithCancel(context.Background())

	cancelChannel := make(chan os.Signal, 1)
	signal.Notify(cancelChannel, os.Interrupt, os.Signal(syscall.SIGTERM))

	go func() {
		<-cancelChannel
		cancel()
	}()

	mux := http.NewServeMux()
	mux.Handle("/", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		w.Write([]byte("Hello, World!"))
	}))

	mux2 := http.NewServeMux()
	mux2.Handle("/", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		w.Write([]byte("Hello from server 2"))
	}))

	server := &http.Server{
		Addr:    ":8080",
		Handler: mux,
		BaseContext: func(listener net.Listener) context.Context {
			return ctx
		},
	}

	server2 := &http.Server{
		Addr:    ":8081",
		Handler: mux2,
		BaseContext: func(listener net.Listener) context.Context {
			return ctx
		},
	}

	serverChannel := make(chan error, 1)
	go func() {
		fmt.Println("starting server 1")
		serverChannel <- server.ListenAndServe()
	}()

	server2Channel := make(chan error, 1)
	go func() {
		fmt.Println("starting server 2")
		server2Channel <- server2.ListenAndServe()
	}()

	select {
	case <-ctx.Done():
		fmt.Println("shutting down server")
		server.Shutdown(ctx)
		server2.Shutdown(ctx)
	case err := <-serverChannel:
		fmt.Printf("server stopped: %v\n", err)
	case err := <-server2Channel:
		fmt.Printf("server2 stopped: %v\n", err)
	}
}