Function daemonize

daemon.go:169–217

(config *server.Configuration)

}

func daemonize(config *server.Configuration) (err error) {
	checkDaemonIsRunning := func() (isRunning bool, err error) {
		var fd int
		fd, err = unix.Open(config.GetLockFile(), os.O_RDONLY, 0600)
		if errors.Is(err, os.ErrNotExist) {
			err = nil
			isRunning = false
			return
		} else if err != nil {
			return
		}

		defer func() {
			err = unix.Close(fd)
		}()
		err = unix.Flock(fd, unix.LOCK_EX|unix.LOCK_NB)
		if errors.Is(err, unix.EWOULDBLOCK) {
			err = nil
			isRunning = true
			return
		} else if err != nil {
			return
		}
		isRunning = false
		err = unix.Flock(fd, unix.LOCK_UN)
		return
	}

	var isRunning bool
	isRunning, err = checkDaemonIsRunning()
	if err != nil {
		return
	}
	if isRunning {
		return
	}

	var executable string
	executable, err = os.Executable()
	if err != nil {
		return
	}
	cmd := exec.Command(executable, "daemon")
	err = cmd.Run()
	if err != nil {
		err = fmt.Errorf("\"%s daemonize\" error: %w", executable, err)
	}
	return
}