ファイルの変更を検知してサーバーを再起動するサンプル

main.go

package main

import (
	"fmt"
	"log"
	"time"

	"net/http"

	"github.com/radovskyb/watcher"
	"golang.org/x/net/context"
)

func main() {
	w := watcher.New()
	srv := startServer("first time")

	// starting file watch
	i := 0
	go func() {
		for {
			select {
			case event := <-w.Event:
				fmt.Println(event)
				if event.Op == watcher.Create {
					fmt.Println("shutdown request")
					ctx, _ := context.WithTimeout(context.Background(), 1*time.Second)
					srv.Shutdown(ctx)
					fmt.Println("restart request")
					i = i + 1
					srv = startServer(fmt.Sprintf("second time later %d", i))
				}
			case err := <-w.Error:
				log.Fatalln(err)
			case <-w.Closed:
				return
			}
		}
	}()

	if err := w.Add("."); err != nil {
		log.Fatalln(err)
	}
	// Print a list of all of the files and folders currently
	// being watched and their paths.
	for path, f := range w.WatchedFiles() {
		fmt.Printf("%s: %s\n", path, f.Name())
	}

	fmt.Println()

	// Trigger 2 events after watcher started.
	go func() {
		w.Wait()
		// w.TriggerEvent(watcher.Create, nil)
		// w.TriggerEvent(watcher.Remove, nil)
	}()

	// Start the watching process - it'll check for changes every 100ms.
	if err := w.Start(time.Millisecond * 100); err != nil {
		log.Fatalln(err)
	}
}

func createHandler(test string) http.Handler {
	m := http.NewServeMux()
	m.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintf(w, test)
	})
	return m
}

func startServer(test string) *http.Server {

	s := http.Server{
		Addr:    ":4000",
		Handler: createHandler(test),
	}
	go func() {
		if err := s.ListenAndServe(); err != nil {
			log.Println("stopped", err)
		}
	}()
	return &s
}