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from StringIO import StringIO
from xml.etree import cElementTree as et
from cloudcontrol.node.tags import Tag, tag_inspector
from cloudcontrol.node.hypervisor import lib as _libvirt
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
NetworkInterface = namedtuple('NetworkInterface', ('source', 'mac', 'model'))
class VirtualMachine(object):
"""Represent a VM instance."""
#: buffer size for console connection handling
BUFFER_LEN = 1024
"""
:param dom: libvirt domain instance
self.hypervisor = weakref.proxy(hypervisor)
#: UUID string of domain
self.uuid = dom.UUIDString()
#: state of VM: started, stoped, paused
self.tags = dict((t.name, t) for t in tag_inspector(vm_tags, self))
# define dynamic tags
i = 0
for v in 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),
i = 0
for nic in self.iter_nics():
for t in (
Tag('nic%s_mac' % i, nic.mac, 10),
Tag('nic%s_source' % i, nic.source, 10),
Tag('nic%s_model' %i, nic.model, 10),
#: 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
@property
def state(self):
return self._state
@state.setter
def state(self, value):
self._state = value
self.tags['vncport'].update_value()
@property
def lv_dom(self):
"""Libvirt domain instance."""
return self.hypervisor.vir_con.lookupByUUIDString(self.uuid)
def start(self):
self.lv_dom.create()
def stop(self):
self.lv_dom.shutdown()
def suspend(self):
self.lv_dom.suspend()
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_ not in ('file', 'block'):
continue
path = d.find('source').get(dict(file='file', block='dev')[type_])
volume = self.hypervisor.storage.get_volume(path)
if volume is None:
continue
yield volume
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@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
yield NetworkInterface(
mac=mac,
source=source,
model=model,
)
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def open_console(self):
if self.stream is not None:
raise ConsoleAlreadyOpened
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