python-compute/compute/utils/diskutils.py
2023-12-13 01:42:50 +03:00

46 lines
1.5 KiB
Python

# This file is part of Compute
#
# Compute is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Compute 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 Compute. If not, see <http://www.gnu.org/licenses/>.
"""Auxiliary functions for working with disks."""
import string
def get_disk_target(
disks: list[str], prefix: str, *, from_end: bool = False
) -> str:
"""
Return free disk name.
.. code-block:: shell-session
>>> get_disk_target(['vda', 'vdb'], 'vd')
'vdc'
>>> get_disk_target(['vda', 'vdc'], 'vd')
'vdb'
>>> get_disk_target(['vda', 'vdd'], 'vd', from_end=True)
'vdz'
>>> get_disk_target(['vda', 'hda'], 'hd')
'hdb'
:param disks: List of attached disk names.
:param prefix: Disk name prefix.
:param from_end: If True select a drive letter starting from the
end of the alphabet.
"""
index = -1 if from_end else 0
devs = [d[-1] for d in disks if d.startswith(prefix)]
return prefix + [x for x in string.ascii_lowercase if x not in devs][index]