Multiple web servers from a single Go binary.

multiserve.go

// multiserve - serve multiple web sites from one Go binary.
// ----------
// Just a demo for now.  (C) Kevin Frost, github: biztos;
// MIT license if you like.

package main

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

type Server struct {
	Name string
	Mux  *http.ServeMux
	Port int
}

func (s *Server) Serve() {
	fmt.Printf("%s server listening on port %d.\n", s.Name, s.Port)
	portStr := fmt.Sprintf(":%d", s.Port)
	http.ListenAndServe(portStr, s.Mux)
}

func NewServer(name string, port int) *Server {

	homeHandler := func(w http.ResponseWriter, r *http.Request) {
		log.Printf("%s shall serve!\n", name)
		msg := fmt.Sprintf("Hello %s World!\n", name)
		w.Write([]byte(msg))
	}

	mux := http.NewServeMux()
	mux.HandleFunc("/", homeHandler)

	return &Server{
		Name: name,
		Port: port,
		Mux:  mux,
	}
}

func main() {

	// Set up a router for each server.  Here we just use two but
	// you could probably have lots and lots.
	servers := []*Server{
		NewServer("Foo", 8001),
		NewServer("Bar", 8002),
	}

	// Start them using goroutines, but *not* for the last one:
	final := len(servers) - 1
	for i, s := range servers {
		if i == final {
			s.Serve()
		} else {
			go s.Serve()
		}
	}
}