python-compute/compute/storage/pool.py
2023-12-03 23:25:34 +03:00

125 lines
4.1 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/>.
"""Manage storage pools."""
import logging
from pathlib import Path
from typing import NamedTuple
import libvirt
from lxml import etree
from compute.exceptions import StoragePoolError, VolumeNotFoundError
from .volume import Volume, VolumeConfig
log = logging.getLogger(__name__)
class StoragePoolUsageInfo(NamedTuple):
"""Storage pool usage info."""
capacity: int
allocation: int
available: int
class StoragePool:
"""Storage pool manipulating class."""
def __init__(self, pool: libvirt.virStoragePool):
"""Initislise StoragePool."""
self.pool = pool
self.name = pool.name()
self.path = self._get_path()
def _get_path(self) -> Path:
"""Return storage pool path."""
xml = etree.fromstring(self.pool.XMLDesc())
return Path(xml.xpath('/pool/target/path/text()')[0])
def get_usage_info(self) -> StoragePoolUsageInfo:
"""Return info about storage pool usage."""
xml = etree.fromstring(self.pool.XMLDesc())
return StoragePoolUsageInfo(
capacity=int(xml.xpath('/pool/capacity/text()')[0]),
allocation=int(xml.xpath('/pool/allocation/text()')[0]),
available=int(xml.xpath('/pool/available/text()')[0]),
)
def dump_xml(self) -> str:
"""Return storage pool XML description as string."""
return self.pool.XMLDesc()
def refresh(self) -> None:
"""Refresh storage pool."""
# TODO @ge: handle libvirt asynchronous job related exceptions
self.pool.refresh()
def create_volume(self, vol_conf: VolumeConfig) -> Volume:
"""Create storage volume and return Volume instance."""
log.info(
'Create storage volume vol=%s in pool=%s', vol_conf.name, self.name
)
vol = self.pool.createXML(
vol_conf.to_xml(),
flags=libvirt.VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA,
)
return Volume(self.pool, vol)
def clone_volume(self, src: Volume, dst: VolumeConfig) -> Volume:
"""
Make storage volume copy.
:param src: Input volume
:param dst: Output volume config
"""
log.info(
'Start volume cloning '
'src_pool=%s src_vol=%s dst_pool=%s dst_vol=%s',
src.pool_name,
src.name,
self.pool.name,
dst.name,
)
vol = self.pool.createXMLFrom(
dst.to_xml(), # new volume XML description
src.vol, # source volume virStorageVol object
flags=libvirt.VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA,
)
if vol is None:
raise StoragePoolError
return Volume(self.pool, vol)
def get_volume(self, name: str) -> Volume | None:
"""Lookup and return Volume instance or None."""
log.info(
'Lookup for storage volume vol=%s in pool=%s', name, self.pool.name
)
try:
vol = self.pool.storageVolLookupByName(name)
return Volume(self.pool, vol)
except libvirt.libvirtError as e:
if e.get_error_code() == libvirt.VIR_ERR_NO_STORAGE_VOL:
raise VolumeNotFoundError(name) from e
log.exception('unexpected error from libvirt')
raise StoragePoolError(e) from e
def list_volumes(self) -> list[Volume]:
"""Return list of volumes in storage pool."""
return [Volume(self.pool, vol) for vol in self.pool.listAllVolumes()]