charm-neutron-openvswitch/hooks/charmhelpers/contrib/storage/linux/utils.py

72 lines
2.4 KiB
Python

# Copyright 2014-2015 Canonical Limited.
#
# This file is part of charm-helpers.
#
# charm-helpers is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3 as
# published by the Free Software Foundation.
#
# charm-helpers 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 Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>.
import os
import re
from stat import S_ISBLK
from subprocess import (
check_call,
check_output,
call
)
def is_block_device(path):
'''
Confirm device at path is a valid block device node.
:returns: boolean: True if path is a block device, False if not.
'''
if not os.path.exists(path):
return False
return S_ISBLK(os.stat(path).st_mode)
def zap_disk(block_device):
'''
Clear a block device of partition table. Relies on sgdisk, which is
installed as pat of the 'gdisk' package in Ubuntu.
:param block_device: str: Full path of block device to clean.
'''
# https://github.com/ceph/ceph/commit/fdd7f8d83afa25c4e09aaedd90ab93f3b64a677b
# sometimes sgdisk exits non-zero; this is OK, dd will clean up
call(['sgdisk', '--zap-all', '--', block_device])
call(['sgdisk', '--clear', '--mbrtogpt', '--', block_device])
dev_end = check_output(['blockdev', '--getsz',
block_device]).decode('UTF-8')
gpt_end = int(dev_end.split()[0]) - 100
check_call(['dd', 'if=/dev/zero', 'of=%s' % (block_device),
'bs=1M', 'count=1'])
check_call(['dd', 'if=/dev/zero', 'of=%s' % (block_device),
'bs=512', 'count=100', 'seek=%s' % (gpt_end)])
def is_device_mounted(device):
'''Given a device path, return True if that device is mounted, and False
if it isn't.
:param device: str: Full path of the device to check.
:returns: boolean: True if the path represents a mounted device, False if
it doesn't.
'''
is_partition = bool(re.search(r".*[0-9]+\b", device))
out = check_output(['mount']).decode('UTF-8')
if is_partition:
return bool(re.search(device + r"\b", out))
return bool(re.search(device + r"[0-9]*\b", out))