1 # Copyright 2015 The Chromium Authors. All rights reserved. 2 # Use of this source code is governed by a BSD-style license that can be 3 # found in the LICENSE file. 4 5 """This module provides some utilities used by LXC and its tools. 6 """ 7 8 import common 9 from autotest_lib.client.bin import utils 10 from autotest_lib.client.common_lib import error 11 from autotest_lib.client.common_lib.cros.network import interface 12 13 14 def path_exists(path): 15 """Check if path exists. 16 17 If the process is not running with root user, os.path.exists may fail to 18 check if a path owned by root user exists. This function uses command 19 `test -e` to check if path exists. 20 21 @param path: Path to check if it exists. 22 23 @return: True if path exists, otherwise False. 24 """ 25 try: 26 utils.run('sudo test -e "%s"' % path) 27 return True 28 except error.CmdError: 29 return False 30 31 32 def get_host_ip(): 33 """Get the IP address of the host running containers on lxcbr*. 34 35 This function gets the IP address on network interface lxcbr*. The 36 assumption is that lxc uses the network interface started with "lxcbr". 37 38 @return: IP address of the host running containers. 39 """ 40 # The kernel publishes symlinks to various network devices in /sys. 41 result = utils.run('ls /sys/class/net', ignore_status=True) 42 # filter out empty strings 43 interface_names = [x for x in result.stdout.split() if x] 44 45 lxc_network = None 46 for name in interface_names: 47 if name.startswith('lxcbr'): 48 lxc_network = name 49 break 50 if not lxc_network: 51 raise error.ContainerError('Failed to find network interface used by ' 52 'lxc. All existing interfaces are: %s' % 53 interface_names) 54 netif = interface.Interface(lxc_network) 55 return netif.ipv4_address 56
