charm-ceilometer-agent/hooks/charmhelpers/contrib/storage/linux/utils.py

54 lines
1.6 KiB
Python

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.
'''
# sometimes sgdisk exits non-zero; this is OK, dd will clean up
call(['sgdisk', '--zap-all', '--mbrtogpt',
'--clear', block_device])
dev_end = check_output(['blockdev', '--getsz', block_device])
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'])
if is_partition:
return bool(re.search(device + r"\b", out))
return bool(re.search(device + r"[0-9]+\b", out))