71 lines
2.3 KiB
Python
71 lines
2.3 KiB
Python
# Copyright 2014-2015 Canonical Limited.
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#
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# This file is part of charm-helpers.
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#
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# charm-helpers is free software: you can redistribute it and/or modify
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# it under the terms of the GNU Lesser General Public License version 3 as
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# published by the Free Software Foundation.
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#
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# charm-helpers is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU Lesser General Public License for more details.
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#
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# You should have received a copy of the GNU Lesser General Public License
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# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>.
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import os
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import re
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from stat import S_ISBLK
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from subprocess import (
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check_call,
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check_output,
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call
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)
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def is_block_device(path):
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'''
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Confirm device at path is a valid block device node.
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:returns: boolean: True if path is a block device, False if not.
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'''
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if not os.path.exists(path):
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return False
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return S_ISBLK(os.stat(path).st_mode)
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def zap_disk(block_device):
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'''
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Clear a block device of partition table. Relies on sgdisk, which is
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installed as pat of the 'gdisk' package in Ubuntu.
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:param block_device: str: Full path of block device to clean.
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'''
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# sometimes sgdisk exits non-zero; this is OK, dd will clean up
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call(['sgdisk', '--zap-all', '--mbrtogpt',
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'--clear', block_device])
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dev_end = check_output(['blockdev', '--getsz',
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block_device]).decode('UTF-8')
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gpt_end = int(dev_end.split()[0]) - 100
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check_call(['dd', 'if=/dev/zero', 'of=%s' % (block_device),
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'bs=1M', 'count=1'])
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check_call(['dd', 'if=/dev/zero', 'of=%s' % (block_device),
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'bs=512', 'count=100', 'seek=%s' % (gpt_end)])
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def is_device_mounted(device):
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'''Given a device path, return True if that device is mounted, and False
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if it isn't.
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:param device: str: Full path of the device to check.
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:returns: boolean: True if the path represents a mounted device, False if
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it doesn't.
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'''
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is_partition = bool(re.search(r".*[0-9]+\b", device))
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out = check_output(['mount']).decode('UTF-8')
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if is_partition:
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return bool(re.search(device + r"\b", out))
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return bool(re.search(device + r"[0-9]+\b", out))
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