Skip to content

Gelencsér Szabolcs / vmdriver

Go to a project
Commit 6a91b611 by Guba Sándor
Options

vmdriver: static connection class and fixing pep issues.

parent a99cac51
Showing with 159 additions and 78 deletions
vmdriver.py
""" Driver for libvirt. """
import libvirt
import logging
import os
......@@ -8,7 +9,6 @@ from vmcelery import celery, lib_connection
sys.path.append(os.path.dirname(os.path.basename(__file__)))
connection = None
state_dict = {0: 'NOSTATE',
1: 'RUNNING',
......@@ -21,16 +21,51 @@ state_dict = {0: 'NOSTATE',
}
#class Singleton(type):
#
# """ Singleton class."""
#
# _instances = {}
#
# def __call__(cls, *args, **kwargs):
# if cls not in cls._instances:
# cls._instances[cls] = super(Singleton, cls).__call__(*args,
# **kwargs)
# return cls._instances[cls]
class Connection(object):
""" Singleton class to handle connection."""
# __metaclass__ = Singleton
connection = None
@classmethod
def get(cls):
""" Return the libvirt connection."""
return cls.connection
@classmethod
def set(cls, connection):
""" Set the libvirt connection."""
cls.connection = connection
@decorator
def req_connection(original_function, *args, **kw):
'''Connection checking decorator for libvirt.
"""Connection checking decorator for libvirt.
If envrionment variable LIBVIRT_KEEPALIVE is set
it will use the connection from the celery worker.
Return the decorateed function
If envrionment variable LIBVIRT_KEEPALIVE is set
it will use the connection from the celery worker.
'''
"""
logging.debug("Decorator running")
global connection
if connection is None:
if Connection.get() is None:
connect()
try:
logging.debug("Decorator calling original function")
......@@ -48,6 +83,11 @@ def req_connection(original_function, *args, **kw):
@decorator
def wrap_libvirtError(original_function, *args, **kw):
""" Decorator to wrap libvirt error in simple Exception.
Return decorated function
"""
try:
return original_function(*args, **kw)
except libvirt.libvirtError as e:
......@@ -60,34 +100,34 @@ def wrap_libvirtError(original_function, *args, **kw):
@celery.task
@wrap_libvirtError
def connect(connection_string='qemu:///system'):
'''Connect to the libvirt daemon specified in the
connection_string or the local root.
'''
global connection
""" Connect to the libvirt daemon.
String is specified in the connection_string parameter
the default is the local root.
"""
if os.getenv('LIBVIRT_KEEPALIVE') is None:
if connection is None:
connection = libvirt.open(connection_string)
if Connection.get() is None:
Connection.set(libvirt.open(connection_string))
logging.debug("Connection estabilished to libvirt.")
else:
logging.debug("There is already an active connection to libvirt.")
else:
connection = lib_connection
Connection.set(lib_connection)
logging.debug("Using celery libvirt connection connection.")
@celery.task
@wrap_libvirtError
def disconnect():
'''Disconnect from the active libvirt daemon connection.
'''
global connection
""" Disconnect from the active libvirt daemon connection."""
if os.getenv('LIBVIRT_KEEPALIVE') is None:
if connection is None:
if Connection.get() is None:
logging.debug('There is no available libvirt conection.')
else:
connection.close()
Connection.get().close()
logging.debug('Connection closed to libvirt.')
connection = None
Connection.set(None)
else:
logging.debug('Keepalive connection should not close.')
......@@ -96,9 +136,8 @@ def disconnect():
@req_connection
@wrap_libvirtError
def define(vm):
'''Define permanent virtual machine from xml
'''
connection.defineXML(vm.dump_xml())
""" Define permanent virtual machine from xml. """
Connection.get().defineXML(vm.dump_xml())
logging.info("Virtual machine %s is defined from xml", vm.name)
......@@ -106,14 +145,17 @@ def define(vm):
@req_connection
@wrap_libvirtError
def create(vm_desc):
'''Create and start non-permanent virtual machine from xml
""" Create and start non-permanent virtual machine from xml.
Return the domain info dict.
flags can be:
VIR_DOMAIN_NONE = 0
VIR_DOMAIN_START_PAUSED = 1
VIR_DOMAIN_START_AUTODESTROY = 2
VIR_DOMAIN_START_BYPASS_CACHE = 4
VIR_DOMAIN_START_FORCE_BOOT = 8
'''
"""
vm = VMInstance.deserialize(vm_desc)
# Setting proper hypervisor
vm.vm_type = os.getenv("HYPERVISOR_TYPE", "test")
......@@ -121,15 +163,15 @@ def create(vm_desc):
logging.info(xml)
# Emulating DOMAIN_START_PAUSED FLAG behaviour on test driver
if vm.vm_type == "test":
connection.createXML(
Connection.get().createXML(
xml, libvirt.VIR_DOMAIN_NONE)
domain = lookupByName(vm.name)
domain.suspend()
# Real driver create
else:
connection.createXML(
vm.dump_xml(), libvirt.VIR_DOMAIN_START_PAUSED)
logging.info("Virtual machine %s is created from xml", vm.name)
Connection.get().createXML(
vm.dump_xml(), libvirt.VIR_DOMAIN_START_PAUSED)
logging.info("Virtual machine %s is created from xml", vm.name)
return domain_info(vm.name)
......@@ -137,19 +179,17 @@ def create(vm_desc):
@req_connection
@wrap_libvirtError
def shutdown(name):
'''Shutdown virtual machine (need ACPI support).
'''
""" Shutdown virtual machine (need ACPI support). """
domain = lookupByName(name)
domain.shutdown()
return _parse_info(domain.info())
@celery.task
@req_connection
@wrap_libvirtError
def delete(name):
'''Destroy the running called 'name' virtual machine.
'''
""" Destroy the running called 'name' virtual machine. """
domain = lookupByName(name)
domain.destroy()
......@@ -158,12 +198,14 @@ def delete(name):
@req_connection
@wrap_libvirtError
def list_domains():
'''
:return list: List of domains name in host
'''
""" List the running domains.
:return list: List of domains name in host.
"""
domain_list = []
for i in connection.listDomainsID():
dom = connection.lookupByID(i)
for i in Connection.get().listDomainsID():
dom = Connection.get().lookupByID(i)
domain_list.append(dom.name())
return domain_list
......@@ -172,18 +214,19 @@ def list_domains():
@req_connection
@wrap_libvirtError
def lookupByName(name):
'''Return with the requested Domain
'''
return connection.lookupByName(name)
""" Return with the requested Domain. """
return Connection.get().lookupByName(name)
@celery.task
@req_connection
@wrap_libvirtError
def undefine(name):
'''Undefine an already defined virtual machine.
If it's running it becomes transient (lsot on reboot)
'''
""" Undefine an already defined virtual machine.
If it's running it becomes transient (lost on reboot)
"""
domain = lookupByName(name)
domain.undefine()
......@@ -192,8 +235,8 @@ def undefine(name):
@req_connection
@wrap_libvirtError
def start(name):
'''Start an already defined virtual machine.
'''
""" Start an already defined virtual machine."""
domain = lookupByName(name)
domain.create()
......@@ -202,8 +245,12 @@ def start(name):
@req_connection
@wrap_libvirtError
def suspend(name):
'''Stop virtual machine and keep memory in RAM.
'''
""" Stop virtual machine and keep memory in RAM.
Return the domain info dict.
"""
domain = lookupByName(name)
domain.suspend()
return _parse_info(domain.info())
......@@ -213,8 +260,8 @@ def suspend(name):
@req_connection
@wrap_libvirtError
def save(name, path):
'''Stop virtual machine and save its memory to path.
'''
""" Stop virtual machine and save its memory to path. """
domain = lookupByName(name)
domain.save(path)
......@@ -223,9 +270,14 @@ def save(name, path):
@req_connection
@wrap_libvirtError
def restore(name, path):
'''Restore a saved virtual machine
from the memory image stored at path.'''
connection.restore(path)
""" Restore a saved virtual machine.
Restores the virtual machine from the memory image
stored at path.
Return the domain info dict.
"""
Connection.get().restore(path)
return domain_info(name)
......@@ -233,8 +285,12 @@ def restore(name, path):
@req_connection
@wrap_libvirtError
def resume(name):
'''Resume stopped virtual machines.
'''
""" Resume stopped virtual machines.
Return the domain info dict.
"""
domain = lookupByName(name)
domain.resume()
return _parse_info(domain.info())
......@@ -244,8 +300,12 @@ def resume(name):
@req_connection
@wrap_libvirtError
def reset(name):
'''Reset (power reset) virtual machine.
'''
""" Reset (power reset) virtual machine.
Return the domain info dict.
"""
domain = lookupByName(name)
domain.reset()
return _parse_info(domain.info())
......@@ -255,8 +315,11 @@ def reset(name):
@req_connection
@wrap_libvirtError
def reboot(name):
'''Reboot (with guest acpi support) virtual machine.
'''
""" Reboot (with guest acpi support) virtual machine.
Return the domain info dict.
"""
domain = lookupByName(name)
domain.reboot()
return _parse_info(domain.info())
......@@ -266,7 +329,10 @@ def reboot(name):
@req_connection
@wrap_libvirtError
def node_info():
''' Get info from Host as dict:
""" Get info from Host as dict.
Return dict:
model string indicating the CPU model
memory memory size in kilobytes
cpus the number of active CPUs
......@@ -279,15 +345,22 @@ def node_info():
cores number of cores per socket, total number of
processors in case of unusual NUMA topolog
threads number of threads per core, 1 in case of unusual numa topology
'''
"""
keys = ['model', 'memory', 'cpus', 'mhz',
'nodes', 'sockets', 'cores', 'threads']
values = connection.getInfo()
values = Connection.get().getInfo()
return dict(zip(keys, values))
def _parse_info(values):
'''Parse libvirt domain info into dict'''
""" Parse libvirt domain info into dict.
Return the info dict.
"""
keys = ['state', 'maxmem', 'memory', 'virtcpunum', 'cputime']
info = dict(zip(keys, values))
# Change state to proper ENUM
......@@ -299,13 +372,16 @@ def _parse_info(values):
@req_connection
@wrap_libvirtError
def domain_info(name):
'''
""" Get the domain info from libvirt.
Return the domain info dict:
state the running state, one of virDomainState
maxmem the maximum memory in KBytes allowed
memory the memory in KBytes used by the domain
virtcpunum the number of virtual CPUs for the domain
cputime the CPU time used in nanoseconds
'''
"""
dom = lookupByName(name)
return _parse_info(dom.info())
......@@ -314,7 +390,8 @@ def domain_info(name):
@req_connection
@wrap_libvirtError
def network_info(name, network):
'''
""" Return the network info dict.
rx_bytes
rx_packets
rx_errs
......@@ -323,7 +400,8 @@ def network_info(name, network):
tx_packets
tx_errs
tx_drop
'''
"""
keys = ['rx_bytes', 'rx_packets', 'rx_errs', 'rx_drop',
'tx_bytes', 'tx_packets', 'tx_errs', 'tx_drop']
dom = lookupByName(name)
......@@ -336,10 +414,12 @@ def network_info(name, network):
@req_connection
@wrap_libvirtError
def send_key(name, key_code):
''' Sending linux key_code to the name vm
key_code can be optained from linux_keys.py
e.x: linuxkeys.KEY_RIGHTCTRL
'''
""" Sending linux key_code to the name vm.
key_code can be optained from linux_keys.py
e.x: linuxkeys.KEY_RIGHTCTRL
"""
domain = lookupByName(name)
domain.sendKey(libvirt.VIR_KEYCODE_SET_LINUX, 100, [key_code], 1, 0)
......@@ -353,19 +433,20 @@ def _stream_handler(stream, buf, opaque):
@req_connection
@wrap_libvirtError
def screenshot(name, path):
"""Save screenshot of virtual machine
to the path as name-screenshot.ppm
"""Save screenshot of virtual machine.
Image is saved to the path as name-screenshot.ppm
"""
# Import linuxkeys to get defines
import linuxkeys
# Connection need for the stream object
global connection
domain = lookupByName(name)
# Send key to wake up console
domain.sendKey(libvirt.VIR_KEYCODE_SET_LINUX,
100, [linuxkeys.KEY_RIGHTCTRL], 1, 0)
# Create Stream to get data
stream = connection.newStream(0)
stream = Connection.get().newStream(0)
# Take screenshot accessible by stream (return mimetype)
domain.screenshot(stream, 0, 0)
# Get file to save data (TODO: send on AMQP?)
......@@ -383,7 +464,7 @@ def screenshot(name, path):
@req_connection
@wrap_libvirtError
def migrate(name, host, live=False):
'''Migrate domain to host'''
""" Migrate domain to host. """
flags = libvirt.VIR_MIGRATE_PEER2PEER
if live:
flags = flags | libvirt.VIR_MIGRATE_LIVE
......@@ -393,4 +474,4 @@ def migrate(name, host, live=False):
flags=flags,
dname=name,
bandwidth=0)
#return _parse_info(domain.info())
# return _parse_info(domain.info())
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or sign in to comment