gracefull_shutdown.go

package main

import (
	"context"
	"log"
	"os"
	"os/signal"
	"sync"
	"syscall"
	"time"
)

func main() {
	ctx, cancel := context.WithCancel(context.Background())
	wg := sync.WaitGroup{}
	wg.Add(1)
	go func() {
		defer wg.Done()
		err := work(ctx)
		if err != nil {
			log.Println("worker stopped with err == ", err)
		}
	}()

	sigChan := make(chan os.Signal, 1)
	signal.Notify(sigChan,
		syscall.SIGHUP,
		syscall.SIGINT,
		syscall.SIGTERM,
		syscall.SIGQUIT)
	//go func() {
	s := <-sigChan
	// поймали один из
	log.Printf("got %v signal", s)
	cancel()

	wg.Wait()
	log.Println("shutdown complete")

	//}()
}

func work(ctx context.Context) error {
	log.Println("worker started")
	for {
		select {
		case <-ctx.Done():
			log.Println("worker got context done")
			return ctx.Err()
		default:
			//some work
			log.Println("worker so some work")
			time.Sleep(1 * time.Second)
		}
	}
}