python-compute/compute/storage/pool.py
2023-11-09 01:17:50 +03:00

115 lines
3.6 KiB
Python

"""Manage storage pools."""
import logging
from pathlib import Path
from typing import NamedTuple
import libvirt
from lxml import etree
from compute.exceptions import StoragePoolError
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()) # noqa: S320
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()) # noqa: S320
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:
# TODO @ge: Raise VolumeNotFoundError instead
if (
e.get_error_domain() == libvirt.VIR_FROM_STORAGE
or e.get_error_code() == libvirt.VIR_ERR_NO_STORAGE_VOL
):
log.exception(e.get_error_message())
return None
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()]