python-compute/compute/session.py

348 lines
12 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/>.
"""Hypervisor session manager."""
import logging
from contextlib import AbstractContextManager
from pathlib import Path
from types import TracebackType
from typing import Any, NamedTuple
from uuid import uuid4
import libvirt
from lxml import etree
from .config import Config
from .exceptions import (
InstanceNotFoundError,
SessionError,
StoragePoolNotFoundError,
)
from .instance import Instance, InstanceConfig, InstanceSchema
from .instance.cloud_init import CloudInit
from .instance.devices import DiskConfig, DiskDriver
from .storage import StoragePool, VolumeConfig
from .utils import diskutils, units
log = logging.getLogger(__name__)
config = Config()
class Capabilities(NamedTuple):
"""Store domain capabilities info."""
arch: str
virt_type: str
emulator: str
machine: str
max_vcpus: int
cpu_vendor: str
cpu_model: str
cpu_features: dict
usable_cpus: list[dict]
class NodeInfo(NamedTuple):
"""
Store compute node info.
See https://libvirt.org/html/libvirt-libvirt-host.html#virNodeInfo
NOTE: memory unit in libvirt docs is wrong! Actual unit is MiB.
"""
arch: str
memory: int
cpus: int
mhz: int
nodes: int
sockets: int
cores: int
threads: int
class Session(AbstractContextManager):
"""Hypervisor session context manager."""
def __init__(self, uri: str | None = None):
"""
Initialise session with hypervisor.
:param uri: libvirt connection URI.
"""
log.debug('Config=%s', config)
self.LIBVIRT_URI = config['libvirt']['uri']
self.IMAGES_POOL = config['storage']['images']
self.VOLUMES_POOL = config['storage']['volumes']
self._uri = uri or self.LIBVIRT_URI
self._connection = libvirt.open(self._uri)
def __enter__(self):
"""Return Session object."""
return self
def __exit__(
self,
exc_type: type[BaseException] | None,
exc_value: BaseException | None,
exc_traceback: TracebackType | None,
):
"""Close the connection when leaving the context."""
self.close()
@property
def uri(self) -> str:
"""Libvirt connection URI."""
return self._uri
@property
def connection(self) -> libvirt.virConnect:
"""Libvirt connection object."""
return self._connection
def close(self) -> None:
"""Close connection to libvirt daemon."""
self.connection.close()
def get_node_info(self) -> NodeInfo:
"""Return information about compute node."""
info = self.connection.getInfo()
return NodeInfo(
arch=info[0],
memory=info[1],
cpus=info[2],
mhz=info[3],
nodes=info[4],
sockets=info[5],
cores=info[6],
threads=info[7],
)
def _cap_get_usable_cpus(self, xml: etree.Element) -> list[dict]:
x = xml.xpath('/domainCapabilities/cpu/mode[@name="custom"]')[0]
cpus = []
for cpu in x.findall('model'):
if cpu.get('usable') == 'yes':
cpus.append( # noqa: PERF401
{
'vendor': cpu.get('vendor'),
'model': cpu.text,
}
)
return cpus
def _cap_get_cpu_features(self, xml: etree.Element) -> dict:
x = xml.xpath('/domainCapabilities/cpu/mode[@name="host-model"]')[0]
require = []
disable = []
for feature in x.findall('feature'):
policy = feature.get('policy')
name = feature.get('name')
if policy == 'require':
require.append(name)
if policy == 'disable':
disable.append(name)
return {'require': require, 'disable': disable}
def get_capabilities(self) -> Capabilities:
"""Return capabilities e.g. arch, virt, emulator, etc."""
prefix = '/domainCapabilities'
hprefix = f'{prefix}/cpu/mode[@name="host-model"]'
caps = etree.fromstring(self.connection.getDomainCapabilities())
return Capabilities(
arch=caps.xpath(f'{prefix}/arch/text()')[0],
virt_type=caps.xpath(f'{prefix}/domain/text()')[0],
emulator=caps.xpath(f'{prefix}/path/text()')[0],
machine=caps.xpath(f'{prefix}/machine/text()')[0],
max_vcpus=int(caps.xpath(f'{prefix}/vcpu/@max')[0]),
cpu_vendor=caps.xpath(f'{hprefix}/vendor/text()')[0],
cpu_model=caps.xpath(f'{hprefix}/model/text()')[0],
cpu_features=self._cap_get_cpu_features(caps),
usable_cpus=self._cap_get_usable_cpus(caps),
)
def create_instance(self, **kwargs: Any) -> Instance:
"""
Create and return new compute instance.
:param name: Instance name.
:type name: str
:param title: Instance title for humans.
:type title: str
:param description: Some information about instance.
:type description: str
:param memory: Memory in MiB.
:type memory: int
:param max_memory: Maximum memory in MiB.
:type max_memory: int
:param vcpus: Number of vCPUs.
:type vcpus: int
:param max_vcpus: Maximum vCPUs.
:type max_vcpus: int
:param cpu: CPU configuration. See :class:`CPUSchema` for info.
:type cpu: dict
:param machine: QEMU emulated machine.
:type machine: str
:param emulator: Path to emulator.
:type emulator: str
:param arch: CPU architecture to virtualization.
:type arch: str
:param boot: Boot settings. See :class:`BootOptionsSchema`.
:type boot: dict
:param image: Source disk image name for system disk.
:type image: str
:param volumes: List of storage volume configs. For more info
see :class:`VolumeSchema`.
:type volumes: list[dict]
:param network: List of virtual network interfaces configs.
See :class:`NetworkSchema` for more info.
:type network_interfaces: list[dict]
:param cloud_init: Cloud-init configuration. See
:class:`CloudInitSchema` for info.
:type cloud_init: dict
"""
data = InstanceSchema(**kwargs)
config = InstanceConfig(data)
log.info('Define instance XML')
log.debug(config.to_xml())
try:
self.connection.defineXML(config.to_xml())
except libvirt.libvirtError as e:
raise SessionError(f'Error defining instance: {e}') from e
log.info('Getting instance object...')
instance = self.get_instance(config.name)
log.info('Start processing volumes...')
log.info('Connecting to images pool...')
images_pool = self.get_storage_pool(self.IMAGES_POOL)
images_pool.refresh()
log.info('Connecting to volumes pool...')
volumes_pool = self.get_storage_pool(self.VOLUMES_POOL)
volumes_pool.refresh()
disk_targets = []
for volume in data.volumes:
log.info('Processing volume=%s', volume)
log.info('Building volume configuration...')
capacity = None
disk_targets.append(volume.target)
if not volume.source:
volume_name = f'{uuid4()}.qcow2'
else:
volume_name = volume.source
if volume.device == 'cdrom':
log.info('Volume %s is CDROM device', volume_name)
elif volume.source is not None:
log.info('Using volume %s as source', volume_name)
if volume.capacity:
capacity = units.to_bytes(
volume.capacity.value, volume.capacity.unit
)
log.info('Getting volume %s', volume.source)
vol = volumes_pool.get_volume(Path(volume_name).name)
log.info(
'Resize volume to specified size: %s',
capacity,
)
vol.resize(capacity, unit=units.DataUnit.BYTES)
else:
capacity = units.to_bytes(
volume.capacity.value, volume.capacity.unit
)
volume_config = VolumeConfig(
name=volume_name,
path=str(volumes_pool.path.joinpath(volume_name)),
capacity=capacity,
)
volume.source = volume_config.path
log.debug('Volume config: %s', volume_config)
if volume.is_system is True and data.image:
log.info(
"Volume is marked as 'system', start cloning image..."
)
log.info('Get image %s', data.image)
image = images_pool.get_volume(data.image)
log.info('Cloning image into volumes pool...')
vol = volumes_pool.clone_volume(image, volume_config)
log.info(
'Resize cloned volume to specified size: %s',
capacity,
)
vol.resize(capacity, unit=units.DataUnit.BYTES)
else:
log.info('Create volume %s', volume_config.name)
volumes_pool.create_volume(volume_config)
log.info('Attaching volume to instance...')
instance.attach_device(
DiskConfig(
type=volume.type,
device=volume.device,
source=volume.source,
target=volume.target,
is_readonly=volume.is_readonly,
bus=volume.bus,
driver=DiskDriver(
volume.driver.name,
volume.driver.type,
volume.driver.cache,
),
)
)
if data.cloud_init:
log.info('Crating disk for cloud-init...')
cloud_init = CloudInit()
cloud_init.user_data = data.cloud_init.user_data
cloud_init.vendor_data = data.cloud_init.vendor_data
cloud_init.network_config = data.cloud_init.network_config
cloud_init.meta_data = data.cloud_init.meta_data
cloud_init_disk_path = volumes_pool.path.joinpath(
f'{instance.name}-cloud-init.img'
)
cloud_init.create_disk(cloud_init_disk_path)
log.info('Attaching cloud-init disk to instance...')
volumes_pool.refresh()
cloud_init.attach_disk(
cloud_init_disk_path,
diskutils.get_disk_target(disk_targets, prefix='vd'),
instance,
)
return instance
def get_instance(self, name: str) -> Instance:
"""Get compute instance by name."""
try:
return Instance(self.connection.lookupByName(name))
except libvirt.libvirtError as e:
if e.get_error_code() == libvirt.VIR_ERR_NO_DOMAIN:
raise InstanceNotFoundError(name) from e
raise SessionError(e) from e
def list_instances(self) -> list[Instance]:
"""List all instances."""
return [Instance(dom) for dom in self.connection.listAllDomains()]
def get_storage_pool(self, name: str) -> StoragePool:
"""Get storage pool by name."""
try:
return StoragePool(self.connection.storagePoolLookupByName(name))
except libvirt.libvirtError as e:
if e.get_error_code() == libvirt.VIR_ERR_NO_STORAGE_POOL:
raise StoragePoolNotFoundError(name) from e
raise SessionError(e) from e
def list_storage_pools(self) -> list[StoragePool]:
"""List all strage pools."""
return [StoragePool(p) for p in self.connection.listStoragePools()]