-
Antoine Millet authored78659913
__init__.py 20.07 KiB
# This file is part of CloudControl.
#
# CloudControl is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# CloudControl 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 Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with CloudControl. If not, see <http://www.gnu.org/licenses/>.
import re
import errno
import logging
import socket
import weakref
from StringIO import StringIO
from xml.etree import cElementTree as et
from collections import namedtuple
from itertools import izip, count
import pyev
import libvirt
from cloudcontrol.common.client.tags import Tag, tag_inspector, TagDB
from cloudcontrol.node.hypervisor.lib import DOMAIN_STATES as STATE
from cloudcontrol.node.hypervisor.domains import vm_tags
from cloudcontrol.node.utils import SocketBuffer
from cloudcontrol.node.exc import ConsoleAlreadyOpened, ConsoleError
logger = logging.getLogger(__name__)
REGEX_TAG_NAME = '[a-zA-Z0-9_-]+'
REGEX_TAG_VALUE = '.+'
REGEX_TAG_IN_DESCRIPTION = '^@(' + REGEX_TAG_NAME + ')[ ]*?=[ ]*?(' + REGEX_TAG_VALUE + ')$'
REGEX_TAG_REPLACE = '^@%s[ ]*?=[ ]*?(' + REGEX_TAG_VALUE + ')$'
NetworkInterface = namedtuple('NetworkInterface', ('source', 'mac', 'model', 'vlans', 'mode'))
class VirtualMachine(object):
"""Represent a VM instance."""
#: buffer size for console connection handling
BUFFER_LEN = 1024
def __init__(self, dom, hypervisor):
"""
:param dom: libvirt domain instance
:param hypervisor: hypervisor where the VM is
"""
self.hypervisor = weakref.proxy(hypervisor)
#: UUID string of domain
self.uuid = dom.UUIDString()
self.name = dom.name()
#: state of VM: started, stoped, paused
self._state = STATE[dom.info()[0]]
#: tags for this VM
self.tag_db = TagDB(tags=tag_inspector(vm_tags, self))
#: Driver cache behavior for each VM storage, see
#: http://libvirt.org/formatdomain.html#elementsDisks
self.cache_behaviour = dict()
# define dynamic tags
for i, v in izip(count(), self.iter_disks()):
for t in (
Tag('disk%s_size' % i, v.capacity, 10),
Tag('disk%s_path' % i, v.path, 10),
Tag('disk%s_pool' % i, v.storage, 10), # FIXME: change
Tag('disk%s_vol' % i, v.name, 10),
Tag('disk%s_cache' % i, lambda: self.cache_behaviour.get(v.path), 10)
):
self.tag_db.add_tag(t)
for i, nic in izip(count(), self.iter_nics()):
for t in (
Tag('nic%s_mac' % i, nic.mac),
Tag('nic%s_source' % i, nic.source),
Tag('nic%s_model' % i, nic.model),
Tag('nic%s_vlans' % i, ' '.join(nic.vlans)),
Tag('nic%s_mode' % i, nic.mode),
):
self.tag_db.add_tag(t)
#: keep record of CPU stats (libev timestamp, cpu time)
self.cpu_stats = (hypervisor.handler.main.evloop.now(), dom.info()[4])
# attributes related to console handling
self.stream = None
self.sock = None # socketpair endpoint
self.read_watcher = None # ev watcher for sock
self.write_watcher = None # ev watcher for sock
self.from_tunnel = None # buffer
self.from_stream = None # buffer
self.stream_handling = 0 # libvirt stream event mask
self.redefine_on_stop = False # for XML update (see KVM class)
self._description_tags_db = TagDB(parent_db=self.tag_db)
self.sync_description_tags()
@property
def state(self):
return self._state
@state.setter
def state(self, value):
self._state = value
self.tag_db['__main__']['status'].update_value()
self.tag_db['__main__']['vncport'].update_value()
self.sync_description_tags()
@property
def title(self):
try:
return self.lv_dom.metadata(libvirt.VIR_DOMAIN_METADATA_TITLE, None)
except (libvirt.libvirtError, AttributeError):
# libvirtError handle the case where the title is not defined on the
# vm, AttributeError handle the case where the libvirt is too old
# to allow metadata handling
return None
@title.setter
def title(self, value):
try:
self.lv_dom.setMetadata(libvirt.VIR_DOMAIN_METADATA_TITLE, value, None, None)
except AttributeError:
raise NotImplementedError('This hv doesn\'t handle VM titles')
else:
self.tag_db['__main__']['t'].update_value()
@property
def description(self):
xml = self.lv_dom.XMLDesc(libvirt.VIR_DOMAIN_XML_INACTIVE)
descriptions = et.ElementTree().parse(StringIO(xml)).findall('description')
if descriptions:
return descriptions[0].text
else:
return ''
@description.setter
def description(self, value):
try:
xml = self.lv_dom.XMLDesc(libvirt.VIR_DOMAIN_XML_INACTIVE)
except libvirt.libvirtError:
logger.exception('Error while getting domain XML from libvirt, %s',
self.name)
raise
xml_tree = et.ElementTree()
root = xml_tree.parse(StringIO(xml))
desc = xml_tree.find('description')
if desc is None:
desc = et.SubElement(root, 'description')
desc.text = value
# write back the XML tree
out = StringIO()
xml_tree.write(out)
try:
self.hypervisor.vir_con.defineXML(out.getvalue())
except libvirt.libvirtError:
logger.exception('Cannot update XML file for domain %s', self.name)
raise
@property
def tags(self):
return dict(re.findall(REGEX_TAG_IN_DESCRIPTION, self.description, re.MULTILINE))
def set_tag(self, tag, value):
if not re.match(REGEX_TAG_NAME + '$', tag):
raise RuntimeError('Bad tag name')
elif not re.match(REGEX_TAG_VALUE + '$', value):
raise RuntimeError('Bad tag value')
tags = self.tags
if tag in tags:
self.description = re.sub(REGEX_TAG_REPLACE % re.escape(tag),
'@%s=%s' % (tag, value),
self.description,
flags=re.MULTILINE)
else:
self.description += '\n@%s=%s' % (tag, value)
def delete_tag(self, tag):
tags = self.tags
if tag in tags:
self.description = re.sub(REGEX_TAG_REPLACE % tag,
'',
self.description,
flags=re.MULTILINE)
@property
def lv_dom(self):
"""Libvirt domain instance."""
return self.hypervisor.vir_con.lookupByUUIDString(self.uuid)
def start(self, pause=False):
flags = 0
if pause:
flags |= libvirt.VIR_DOMAIN_START_PAUSED
self.lv_dom.createWithFlags(flags)
def sync_description_tags(self):
tags = dict(re.findall(REGEX_TAG_IN_DESCRIPTION, self.description, re.MULTILINE))
# Add/update static tags:
for k, v in tags.iteritems():
tag = self._description_tags_db['__main__'].get(k)
if tag is None:
self._description_tags_db.add_tag(Tag(k, v, -1))
else:
tag.value = v
# Purge not more defined static tags:
for k in self._description_tags_db['__main__']:
if k not in tags:
self._description_tags_db.remove_tag(k)
def stop(self):
self.lv_dom.shutdown()
def suspend(self):
self.lv_dom.suspend()
def resume(self):
self.lv_dom.resume()
def destroy(self):
self.lv_dom.destroy()
def undefine(self):
self.lv_dom.undefine()
@property
def disks(self):
return list(self.iter_disks())
def iter_disks(self):
for d in et.ElementTree().parse(
StringIO(self.lv_dom.XMLDesc(0))
).findall('devices/disk'):
if d.get('device') != 'disk':
continue
type_ = d.get('type')
if type_ in ('file', 'block'):
path = d.find('source').get(dict(file='file', block='dev')[type_])
volume = self.hypervisor.storage.get_volume(path)
if volume is None:
continue
elif type_ == 'volume':
pool = d.find('source').get('pool')
vol = d.find('source').get('volume')
volume = self.hypervisor.storage.get_volume_by_pool(pool, vol)
else:
continue
# Ignore unknown volumes:
if volume is None:
logger.warn('Unknown volume for vm %s', self.name)
continue
path = volume.path
# update cache behaviour
driver = d.find('driver')
if driver is None:
driver = {}
self.cache_behaviour[path] = driver.get('cache', 'default')
yield volume
@property
def nics(self):
return list(self.iter_nics())
def iter_nics(self):
for nic in et.ElementTree().parse(
StringIO(self.lv_dom.XMLDesc(0))
).findall('devices/interface'):
if nic.get('type') == 'bridge':
try:
mac = nic.find('mac').get('address')
except AttributeError:
mac = None
try:
model = nic.find('model').get('type')
except AttributeError:
model = None
try:
source = nic.find('source').get('bridge')
except AttributeError:
source = None
vlans = set()
vlan_list = nic.find('vlan')
if vlan_list is not None:
for tag in vlan_list.findall('tag'):
tid = tag.get('id')
if tid is not None:
vlans.add(tid)
mode = {'yes': 'tagged', 'no': 'untagged'}[vlan_list.get('trunk', 'yes' if len(vlans) > 1 else 'no')]
elif source is not None:
mode = 'untagged'
vlans.add(source[2:])
else:
mode = 'unknown'
yield NetworkInterface(
mac=mac,
source=source,
model=model,
vlans=vlans,
mode=mode,
)
def open_console(self):
if self.stream is not None:
raise ConsoleAlreadyOpened('Console for this VM is already'
' opened')
if str(
self.hypervisor.handler.tag_db['__main__']['libvirtver'].value,
).startswith('8'):
raise ConsoleError(
'Cannot open console, not compatible with this version of libvirt')
logger.info('Opening console stream on VM %s', self.name)
try:
self.stream = self.hypervisor.vir_con.newStream(
libvirt.VIR_STREAM_NONBLOCK)
except libvirt.libvirtError:
logger.error('Cannot create new stream for console %s', self.name)
self.close_console()
raise
self.stream_handling = libvirt.VIR_STREAM_EVENT_READABLE | (
libvirt.VIR_STREAM_EVENT_ERROR | libvirt.VIR_STREAM_EVENT_HANGUP)
try:
self.lv_dom.openConsole(None, self.stream, 0)
self.stream.eventAddCallback(self.stream_handling,
self.virt_console_stream_cb,
None)
except libvirt.libvirtError:
logger.error('Cannot open console on domain %s', self.name)
self.close_console()
raise
try:
self.sock, tunnel_endpoint = socket.socketpair()
except socket.error:
logger.error('Cannot create socket pair for console on domain %s',
self.name)
self.close_console()
raise
try:
self.sock.setblocking(0)
except socket.error:
logger.error('Cannot set socket to non blocking for console on'
' domain %s', self.name)
self.close_console()
raise
self.read_watcher = self.hypervisor.handler.main.evloop.io(
self.sock, pyev.EV_READ, self.read_from_tun_cb)
self.read_watcher.start()
self.write_watcher = self.hypervisor.handler.main.evloop.io(
self.sock, pyev.EV_WRITE, self.write_to_tun_cb)
# self.write_watcher.start()
self.from_tunnel = SocketBuffer(4096)
self.from_stream = SocketBuffer(4096)
return tunnel_endpoint
def virt_console_stream_cb(self, stream, events, opaque):
"""Handles read/write from/to libvirt stream."""
if events & libvirt.VIR_EVENT_HANDLE_ERROR or (
events & libvirt.VIR_EVENT_HANDLE_HANGUP):
# error/hangup
# logger.debug('Received error on stream')
self.close_console()
return
if events & libvirt.VIR_EVENT_HANDLE_WRITABLE:
# logger.debug('Write to stream')
# logger.debug('Event %s', self.stream_handling)
while True:
try:
to_send = self.from_tunnel.popleft()
except IndexError:
# update libvirt event mask
self.stream_handling ^= libvirt.VIR_STREAM_EVENT_WRITABLE
self.stream.eventUpdateCallback(self.stream_handling)
break
send_buffer = to_send
total_sent = 0
while True:
try:
written = self.stream.send(send_buffer)
except:
# libvirt send error
logger.exception('Error while writing to stream')
self.close_console()
return
if written == -2: # equivalent to EAGAIN
self.from_tunnel.appendleft(to_send[total_sent:])
break
elif written == len(send_buffer):
break
total_sent += written
send_buffer = buffer(to_send, total_sent)
if not self.from_tunnel.is_full():
self.read_watcher.start()
if events & libvirt.VIR_EVENT_HANDLE_READABLE:
# logger.debug('Read from stream')
# logger.debug('Event %s', self.stream_handling)
while True:
try:
incoming = self.stream.recv(self.BUFFER_LEN)
except:
pass
if incoming == -2:
# equivalent to EAGAIN
break
elif not incoming:
# EOF
self.close_console()
return
self.from_stream.append(incoming)
if self.from_stream.is_full():
# update libvirt event mask
self.stream_handling ^= libvirt.VIR_STREAM_EVENT_READABLE
self.stream.eventUpdateCallback(self.stream_handling)
break
if not self.from_stream.is_empty():
self.write_watcher.start()
def read_from_tun_cb(self, watcher, revents):
"""Read data from tunnel and save into buffer."""
# logger.debug('Read from tunnel')
# logger.debug('Event %s', self.stream_handling)
while True:
try:
incoming = self.sock.recv(self.BUFFER_LEN)
except socket.error as exc:
if exc.errno in (errno.EAGAIN, errno.EWOULDBLOCK):
break
logger.exception('Error reading on socket for vm console')
self.close_console()
return
if not incoming:
# EOF (we could wait before closing console stream)
self.close_console()
return
self.from_tunnel.append(incoming)
if self.from_tunnel.is_full():
self.read_watcher.stop()
break
if not self.from_tunnel.is_empty():
# update libvirt event callback
self.stream_handling |= libvirt.VIR_STREAM_EVENT_WRITABLE
self.stream.eventUpdateCallback(self.stream_handling)
def write_to_tun_cb(self, watcher, revents):
"""Write data from buffer to tunnel."""
# logger.debug('Write to tunnel')
# logger.debug('Event %s', self.stream_handling)
while True:
try:
to_send = self.from_stream.popleft()
except IndexError:
self.write_watcher.stop()
break
send_buffer = to_send
total_sent = 0
while True:
try:
written = self.sock.send(send_buffer)
except socket.error as exc:
if exc.errno in (errno.EAGAIN, errno.EWOULDBLOCK):
self.from_stream.appenleft(to_send[total_sent:])
break
logger.exception('Error writing on socket for vm console')
self.close_console()
return
if written == len(send_buffer):
break
total_sent += written
send_buffer = buffer(to_send, total_sent)
if not self.from_stream.is_full():
# update libvirt event callback
self.stream_handling |= libvirt.VIR_STREAM_EVENT_READABLE
self.stream.eventUpdateCallback(self.stream_handling)
def close_console(self):
logger.info('Closing console stream on VM %s', self.name)
if self.stream is not None:
try:
self.stream.eventRemoveCallback()
except Exception:
logger.error('Error while removing callback on stream')
try:
self.stream.finish()
except Exception:
logger.error('Cannot finnish console stream')
self.stream = None
if self.sock is not None:
try:
self.sock.close()
except socket.error:
logger.error('Cannot close socket')
self.sock = None
if self.read_watcher is not None:
self.read_watcher.stop()
self.read_watcher = None
if self.write_watcher is not None:
self.write_watcher.stop()
self.write_watcher = None
self.from_tunnel = None
self.from_stream = None
def migrate(self, dest_uri, live=False):
volumes = list(self.iter_disks()) # Store volumes for future cleanup
flags = (libvirt.VIR_MIGRATE_PEER2PEER
| libvirt.VIR_MIGRATE_PERSIST_DEST
| libvirt.VIR_MIGRATE_UNDEFINE_SOURCE)
if live:
flags |= (libvirt.VIR_MIGRATE_LIVE
| libvirt.VIR_MIGRATE_NON_SHARED_DISK
| libvirt.VIR_MIGRATE_AUTO_CONVERGE)
else:
flags |= libvirt.VIR_MIGRATE_OFFLINE
error = self.lv_dom.migrateToURI3(dest_uri, {}, flags)
if error:
raise RuntimeError('Unable to migrate VM')
else:
if live: # In live mode, we are responsible for source volume cleaning
for volume in volumes:
# Delete VM storage after migration success:
self.hypervisor.storage.delete_volume(volume.storage, volume.name)