https://github.com/nsqio/go-nsq/issues/171

main.go

// TODO: need to supply your own startService and stopService functions

package main

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

	"github.com/nsqio/go-nsq"
)

func main() {
	stopService("nsqd")
	cfg := nsq.NewConfig()
	p, err := nsq.NewProducer("127.0.0.1:4150", cfg)
	if err != nil {
		log.Fatal(err)
	}

	closeChan := make(chan struct{})

	var wg sync.WaitGroup
	wg.Add(2)

	go func() {
		msg := []byte("nsq")
		i := 0
	loop:
		for {
			if i%10000 == 0 {
				log.Printf("%d successful messages\n", i)
			}
			select {
			case <-closeChan:
				break loop
			default:
				pubErr := p.Publish("hello", msg)
				if pubErr != nil {
					if pubErr.Error() != "not connected" {
						log.Println(pubErr)
					}
				} else {
					i++
				}
			}
		}
		wg.Done()
	}()

	go func() {
	loop2:
		for {
			select {
			case <-time.After(5 * time.Second):
				stopService("nsqd")
				//time.Sleep(5 * time.Second)
				startService("nsqd")
			case <-closeChan:
				break loop2
			}
		}
		wg.Done()
	}()

	notify := make(chan os.Signal, 1)
	signal.Notify(notify, syscall.SIGINT, syscall.SIGTERM)
	<-notify

	log.Println("Exiting...")

	p.Stop()
	close(closeChan)
	wg.Wait()

	stopService("nsqd")

	log.Println("Done")
}