// -*- Mode: Go; indent-tabs-mode: t -*-

/*
 * Copyright (C) 2017 Canonical Ltd
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

package osutil

import (
	"io/ioutil"
	"os"
	"strings"
)

// BootID returns the unique system-generated boot identifier.
func BootID() (string, error) {
	file, err := os.Open("/proc/sys/kernel/random/boot_id")
	if err != nil {
		return "", err
	}
	defer file.Close()
	bytes, err := ioutil.ReadAll(file)
	if err != nil {
		return "", err
	}
	return strings.TrimSpace(string(bytes)), nil
}