openstack nova 源码分析nova/virt/libvirt目录下的connection.py
该文件位于nova/virt/libvirt目录下的connection.py！我只是浅浅的分析了一下类中函数的方法 细节并没有多看，肯定有很多地方是错的 或者不好！希望大家能够帮忙指出错误！ 接下来 看源代码如下：中文部分是我加的注释 ！或许大家会问 为什么要看这个connection.py呢 因为我发现该文件外部virt目录下有个connection.py 其中引用了 这个文件 所以觉得这个应该很重要 而且发现 好多方法都是重写的底层的driver的方法[*]
[*]import hashlib
[*]import functools
[*]import multiprocessing
[*]import netaddr
[*]import os
[*]import random
[*]import re
[*]import shutil
[*]import sys
[*]import tempfile
[*]import time
[*]import uuid
[*]from xml.dom import minidom
[*]from xml.etree import ElementTree
[*]
[*]from eventlet import greenthread
[*]from eventlet import tpool
[*]
[*]from nova import block_device
[*]from nova import context as nova_context
[*]from nova import db
[*]from nova import exception
[*]from nova import flags
[*]import nova.image
[*]from nova import log as logging
[*]from nova import utils
[*]from nova import vnc
[*]from nova.auth import manager
[*]from nova.compute import instance_types
[*]from nova.compute import power_state
[*]from nova.virt import disk
[*]from nova.virt import driver
[*]from nova.virt import images
[*]from nova.virt.libvirt import netutils
[*]
[*]
[*]libvirt = None
[*]libxml2 = None
[*]Template = None
[*]
[*]
[*]LOG = logging.getLogger('nova.virt.libvirt_conn')
[*]
[*]
[*]FLAGS = flags.FLAGS
[*]flags.DECLARE('live_migration_retry_count', 'nova.compute.manager')
[*]# TODO(vish): These flags should probably go into a shared location
[*]#这些标志应该进入共享位置
[*]flags.DEFINE_string('rescue_image_id', None, 'Rescue ami image')
[*]flags.DEFINE_string('rescue_kernel_id', None, 'Rescue aki image')
[*]flags.DEFINE_string('rescue_ramdisk_id', None, 'Rescue ari image')
[*]flags.DEFINE_string('libvirt_xml_template',
[*] utils.abspath('virt/libvirt.xml.template'),
[*] 'Libvirt XML Template')
[*]flags.DEFINE_string('libvirt_type',
[*] 'kvm',
[*] 'Libvirt domain type (valid options are: '
[*] 'kvm, lxc, qemu, uml, xen)')
[*]flags.DEFINE_string('libvirt_uri',
[*] '',
[*] 'Override the default libvirt URI (which is dependent'
[*] ' on libvirt_type)')
[*]flags.DEFINE_bool('allow_same_net_traffic',
[*] True,
[*] 'Whether to allow network traffic from same network')
[*]flags.DEFINE_bool('use_cow_images',
[*] True,
[*] 'Whether to use cow images')
[*]flags.DEFINE_string('ajaxterm_portrange',
[*] '10000-12000',
[*] 'Range of ports that ajaxterm should randomly try to bind')
[*]flags.DEFINE_string('firewall_driver',
[*] 'nova.virt.libvirt.firewall.IptablesFirewallDriver',
[*] 'Firewall driver (defaults to iptables)')
[*]flags.DEFINE_string('cpuinfo_xml_template',
[*] utils.abspath('virt/cpuinfo.xml.template'),
[*] 'CpuInfo XML Template (Used only live migration now)')
[*]flags.DEFINE_string('live_migration_uri',
[*] "qemu+tcp://%s/system",
[*] 'Define protocol used by live_migration feature')
[*]flags.DEFINE_string('live_migration_flag',
[*] "VIR_MIGRATE_UNDEFINE_SOURCE, VIR_MIGRATE_PEER2PEER",
[*] 'Define live migration behavior.')
[*]flags.DEFINE_string('block_migration_flag',
[*] "VIR_MIGRATE_UNDEFINE_SOURCE, VIR_MIGRATE_PEER2PEER, "
[*] "VIR_MIGRATE_NON_SHARED_INC",
[*] 'Define block migration behavior.')
[*]flags.DEFINE_integer('live_migration_bandwidth', 0,
[*] 'Define live migration behavior')
[*]flags.DEFINE_string('snapshot_image_format', None,
[*] 'Snapshot image format (valid options are : '
[*] 'raw, qcow2, vmdk, vdi).'
[*] 'Defaults to same as source image')
[*]flags.DEFINE_string('libvirt_vif_type', 'bridge',
[*] 'Type of VIF to create.')
[*]flags.DEFINE_string('libvirt_vif_driver',
[*] 'nova.virt.libvirt.vif.LibvirtBridgeDriver',
[*] 'The libvirt VIF driver to configure the VIFs.')
[*]flags.DEFINE_string('default_local_format',
[*] None,
[*] 'The default format a local_volume will be formatted with '
[*] 'on creation.')
[*]flags.DEFINE_bool('libvirt_use_virtio_for_bridges',
[*] False,
[*] 'Use virtio for bridge interfaces')
[*]
[*]#get_connection 获得与hypervisor(管理程序)的连接
[*]def get_connection(read_only):
[*] # These are loaded late so that there's no need to install these
[*] # libraries when not using libvirt.
[*] # Cheetah is separate because the unit tests want to load Cheetah,
[*] # but not libvirt.
[*] global libvirt
[*] global libxml2
[*] if libvirt is None:
[*] libvirt = __import__('libvirt')
[*] if libxml2 is None:
[*] libxml2 = __import__('libxml2')
[*] _late_load_cheetah() #实际上是延迟引入模板
[*] return LibvirtConnection(read_only)
[*]
[*]
[*]def _late_load_cheetah():
[*] global Template
[*] if Template is None:
[*] t = __import__('Cheetah.Template', globals(), locals(),
[*] ['Template'], -1)
[*] Template = t.Template
[*]
[*]
[*]def _get_eph_disk(ephemeral):
[*] return 'disk.eph' + str(ephemeral['num'])
[*]
[*]
[*]class LibvirtConnection(driver.ComputeDriver):
[*] #这个类 LibvirtConnection是继承的drive.ComputerDriver
[*] #为了让大家一目了然 后面会插入一个 LibvirtConnection 的类图
[*]
[*] def __init__(self, read_only):
[*] super(LibvirtConnection, self).__init__() #父类的初始化
[*] self.libvirt_uri = self.get_uri()
[*] #2、获得链接
[*] """
[*] self.libvirt_uri = self.get_uri()
[*]
[*] get_uri()函数如下定义。
[*]
[*] def get_uri(self):
[*] if FLAGS.libvirt_type == 'uml':
[*] uri = FLAGS.libvirt_uri or 'uml:///system'
[*] elif FLAGS.libvirt_type == 'xen':
[*] uri = FLAGS.libvirt_uri or 'xen:///'
[*] elif FLAGS.libvirt_type == 'lxc':
[*] uri = FLAGS.libvirt_uri or 'lxc:///'
[*] else:
[*] uri = FLAGS.libvirt_uri or 'qemu:///system'
[*] return uri
[*] """
[*]
[*] #设置模板
[*] self.libvirt_xml = open(FLAGS.libvirt_xml_template).read()
[*] self.cpuinfo_xml = open(FLAGS.cpuinfo_xml_template).read()
[*] self._wrapped_conn = None
[*] self.read_only = read_only
[*] #设置firewall
[*] fw_class = utils.import_class(FLAGS.firewall_driver) #获得类名
[*] self.firewall_driver = fw_class(get_connection=self._get_connection)
[*] #获得链接调用—get_connection
[*] """函数如下
[*] def _get_connection(self):
[*] if not self._wrapped_conn or not self._test_connection():
[*] LOG.debug(_('Connecting to libvirt: %s'), self.libvirt_uri)
[*] self._wrapped_conn = self._connect(self.libvirt_uri,
[*] self.read_only)
[*] #此处是_connect函数 这个函数是从底层libvirt库中拿到链接
[*] #def _connect(self, uri, read_only): auth = [,'root',None]
[*]
[*] # if read_only:
[*] # return libvirt.openReadOnly(uri)
[*] # else:
[*] # return libvirt.openAuth(uri, auth, 0)
[*]
[*] return self._wrapped_conn
[*] """
[*] self.vif_driver = utils.import_object(FLAGS.libvirt_vif_driver)
[*]
[*] def init_host(self, host):
[*] # NOTE(nsokolov): moved instance restarting to ComputeManager
[*] pass
[*]
[*] def _get_connection(self):
[*] #获得链接
[*] if not self._wrapped_conn or not self._test_connection():
[*] LOG.debug(_('Connecting to libvirt: %s'), self.libvirt_uri)
[*] self._wrapped_conn = self._connect(self.libvirt_uri,
[*] self.read_only)
[*] return self._wrapped_conn
[*] _conn = property(_get_connection)
[*]
[*] def _test_connection(self):
[*] #测试链接
[*] try:
[*] self._wrapped_conn.getCapabilities()
[*] return True
[*] except libvirt.libvirtError as e:
[*] if e.get_error_code() == libvirt.VIR_ERR_SYSTEM_ERROR and \
[*] e.get_error_domain() == libvirt.VIR_FROM_REMOTE:
[*] LOG.debug(_('Connection to libvirt broke'))
[*] return False
[*] raise
[*]
[*] def get_uri(self):
[*] #获得url 提供被调用
[*] if FLAGS.libvirt_type == 'uml':
[*] uri = FLAGS.libvirt_uri or 'uml:///system'
[*] elif FLAGS.libvirt_type == 'xen':
[*] uri = FLAGS.libvirt_uri or 'xen:///'
[*] elif FLAGS.libvirt_type == 'lxc':
[*] uri = FLAGS.libvirt_uri or 'lxc:///'
[*] else:
[*] uri = FLAGS.libvirt_uri or 'qemu:///system'
[*] return uri
[*]
[*] def _connect(self, uri, read_only):
[*] #链接
[*] auth = [,
[*] 'root',
[*] None]
[*]
[*] if read_only:
[*] return libvirt.openReadOnly(uri)
[*] else:
[*] return libvirt.openAuth(uri, auth, 0)
[*]
[*] def list_instances(self):
[*] return [self._conn.lookupByID(x).name()
[*] for x in self._conn.listDomainsID()]
[*]
[*] def _map_to_instance_info(self, domain):
[*] #从一个virsh（虚拟）域对象到一个 InstanceInfO得到信息
[*] """Gets info from a virsh domain object into an InstanceInfo"""
[*]
[*] # domain.info() returns a list of:
[*] # state: one of the state values (virDomainState)
[*] # maxMemory: the maximum memory used by the domain
[*] # memory: the current amount of memory used by the domain
[*] # nbVirtCPU: the number of virtual CPU
[*] # puTime: the time used by the domain in nanoseconds
[*]
[*] (state, _max_mem, _mem, _num_cpu, _cpu_time) = domain.info()
[*] name = domain.name()
[*]
[*] return driver.InstanceInfo(name, state)
[*]
[*] def list_instances_detail(self):
[*] #返回一个信息列表
[*] infos = []
[*] for domain_id in self._conn.listDomainsID():
[*] domain = self._conn.lookupByID(domain_id)
[*] info = self._map_to_instance_info(domain)
[*] infos.append(info)
[*] return infos
[*]
[*] def plug_vifs(self, instance, network_info):
[*] #接通VIFs（虚拟接口） 的网络
[*]
[*] """Plugin VIFs into networks."""
[*] for (network, mapping) in network_info:
[*] self.vif_driver.plug(instance, network, mapping)
[*]
[*] def destroy(self, instance, network_info, cleanup=True):
[*] #Destroy (shutdown and delete) the specified instance.
[*]
[*] instance_name = instance['name']
[*]
[*] try:
[*] virt_dom = self._lookup_by_name(instance_name)
[*] except exception.NotFound:
[*] virt_dom = None
[*]
[*] # If the instance is already terminated, we're still happy
[*] # Otherwise, destroy it
[*] if virt_dom is not None:
[*] try:
[*] virt_dom.destroy()
[*] except libvirt.libvirtError as e:
[*] is_okay = False
[*] errcode = e.get_error_code()
[*] if errcode == libvirt.VIR_ERR_OPERATION_INVALID:
[*] # If the instance if already shut off, we get this:
[*] # Code=55 Error=Requested operation is not valid:
[*] # domain is not running
[*] (state, _max_mem, _mem, _cpus, _t) = virt_dom.info()
[*] if state == power_state.SHUTOFF:
[*] is_okay = True
[*]
[*] if not is_okay:
[*] LOG.warning(_("Error from libvirt during destroy of "
[*] "%(instance_name)s. Code=%(errcode)s "
[*] "Error=%(e)s") %
[*] locals())
[*] raise
[*]
[*] try:
[*] # NOTE(justinsb): We remove the domain definition. We probably
[*] # would do better to keep it if cleanup=False (e.g. volumes?)
[*] # (e.g. #2 - not losing machines on failure)
[*] virt_dom.undefine()
[*] except libvirt.libvirtError as e:
[*] errcode = e.get_error_code()
[*] LOG.warning(_("Error from libvirt during undefine of "
[*] "%(instance_name)s. Code=%(errcode)s "
[*] "Error=%(e)s") %
[*] locals())
[*] raise
[*]
[*] for (network, mapping) in network_info:
[*] self.vif_driver.unplug(instance, network, mapping)
[*]
[*] def _wait_for_destroy():
[*] """Called at an interval until the VM is gone."""
[*] instance_name = instance['name']
[*]
[*] try:
[*] state = self.get_info(instance_name)['state']
[*] except exception.NotFound:
[*] msg = _("Instance %s destroyed successfully.") % instance_name
[*] LOG.info(msg)
[*] raise utils.LoopingCallDone
[*]
[*] timer = utils.LoopingCall(_wait_for_destroy)
[*] timer.start(interval=0.5, now=True)
[*]
[*] self.firewall_driver.unfilter_instance(instance,
[*] network_info=network_info)
[*]
[*] if cleanup:
[*] self._cleanup(instance)
[*]
[*] return True
[*]
[*] def _cleanup(self, instance):
[*] target = os.path.join(FLAGS.instances_path, instance['name'])
[*] instance_name = instance['name']
[*] LOG.info(_('instance %(instance_name)s: deleting instance files'
[*] ' %(target)s') % locals())
[*] if FLAGS.libvirt_type == 'lxc':
[*] disk.destroy_container(target, instance, nbd=FLAGS.use_cow_images)
[*] if os.path.exists(target):
[*] shutil.rmtree(target)
[*]
[*] @exception.wrap_exception()
[*] def attach_volume(self, instance_name, device_path, mountpoint):
[*] #在挂载点设置实例磁盘的路径
[*] virt_dom = self._lookup_by_name(instance_name)
[*] mount_device = mountpoint.rpartition("/")
[*] (type, protocol, name) = \
[*] self._get_volume_device_info(device_path)
[*] if type == 'block':
[*] xml = """<disk type='block'>
[*] <driver name='qemu' type='raw'/>
[*] <source dev='%s'/>
[*] <target dev='%s' bus='virtio'/>
[*] </disk>""" % (device_path, mount_device)
[*] elif type == 'network':
[*] xml = """<disk type='network'>
[*] <driver name='qemu' type='raw'/>
[*] <source protocol='%s' name='%s'/>
[*] <target dev='%s' bus='virtio'/>
[*] </disk>""" % (protocol, name, mount_device)
[*] virt_dom.attachDevice(xml)
[*]
[*] def _get_disk_xml(self, xml, device):
[*] """Returns the xml for the disk mounted at device"""
[*] #返回磁盘在设备上磁盘安装的xml
[*] try:
[*] doc = libxml2.parseDoc(xml)
[*] except Exception:
[*] return None
[*] ctx = doc.xpathNewContext()
[*] try:
[*] ret = ctx.xpathEval('/domain/devices/disk')
[*] for node in ret:
[*] for child in node.children:
[*] if child.name == 'target':
[*] if child.prop('dev') == device:
[*] return str(node)
[*] finally:
[*] if ctx is not None:
[*] ctx.xpathFreeContext()
[*] if doc is not None:
[*] doc.freeDoc()
[*]
[*] @exception.wrap_exception()
[*] def detach_volume(self, instance_name, mountpoint):
[*] virt_dom = self._lookup_by_name(instance_name)
[*] mount_device = mountpoint.rpartition("/")
[*] xml = self._get_disk_xml(virt_dom.XMLDesc(0), mount_device)
[*] if not xml:
[*] raise exception.DiskNotFound(location=mount_device)
[*] virt_dom.detachDevice(xml)
[*]
[*] @exception.wrap_exception()
[*] def snapshot(self, context, instance, image_href):
[*] """Create snapshot from a running VM instance.
[*]
[*] This command only works with qemu 0.14+
[*] """
[*] virt_dom = self._lookup_by_name(instance['name'])
[*]
[*] (image_service, image_id) = nova.image.get_image_service(
[*] context, instance['image_ref'])
[*] base = image_service.show(context, image_id)
[*] (snapshot_image_service, snapshot_image_id) = \
[*] nova.image.get_image_service(context, image_href)
[*] snapshot = snapshot_image_service.show(context, snapshot_image_id)
[*]
[*] metadata = {'is_public': False,
[*] 'status': 'active',
[*] 'name': snapshot['name'],
[*] 'properties': {
[*] 'kernel_id': instance['kernel_id'],
[*] 'image_location': 'snapshot',
[*] 'image_state': 'available',
[*] 'owner_id': instance['project_id'],
[*] 'ramdisk_id': instance['ramdisk_id'],
[*] }
[*] }
[*] if 'architecture' in base['properties']:
[*] arch = base['properties']['architecture']
[*] metadata['properties']['architecture'] = arch
[*]
[*] source_format = base.get('disk_format') or 'raw'
[*] image_format = FLAGS.snapshot_image_format or source_format
[*] if FLAGS.use_cow_images:
[*] source_format = 'qcow2'
[*] metadata['disk_format'] = image_format
[*]
[*] if 'container_format' in base:
[*] metadata['container_format'] = base['container_format']
[*]
[*] # Make the snapshot
[*] snapshot_name = uuid.uuid4().hex
[*] snapshot_xml = """
[*] <domainsnapshot>
[*] <name>%s</name>
[*] </domainsnapshot>
[*] """ % snapshot_name
[*] snapshot_ptr = virt_dom.snapshotCreateXML(snapshot_xml, 0)
[*]
[*] # Find the disk
[*] xml_desc = virt_dom.XMLDesc(0)
[*] domain = ElementTree.fromstring(xml_desc)
[*] source = domain.find('devices/disk/source')
[*] disk_path = source.get('file')
[*]
[*] # Export the snapshot to a raw image
[*] temp_dir = tempfile.mkdtemp()
[*] out_path = os.path.join(temp_dir, snapshot_name)
[*] qemu_img_cmd = ('qemu-img',
[*] 'convert',
[*] '-f',
[*] source_format,
[*] '-O',
[*] image_format,
[*] '-s',
[*] snapshot_name,
[*] disk_path,
[*] out_path)
[*] utils.execute(*qemu_img_cmd)
[*]
[*] # Upload that image to the image service
[*] with open(out_path) as image_file:
[*] image_service.update(context,
[*] image_href,
[*] metadata,
[*] image_file)
[*]
[*] # Clean up
[*] shutil.rmtree(temp_dir)
[*] snapshot_ptr.delete(0)
[*]
[*] @exception.wrap_exception()
[*] def reboot(self, instance, network_info, xml=None):
[*] """Reboot a virtual machine, given an instance reference.
[*]
[*] This method actually destroys and re-creates the domain to ensure the
[*] reboot happens, as the guest OS cannot ignore this action.
[*]
[*] """
[*] virt_dom = self._conn.lookupByName(instance['name'])
[*] # NOTE(itoumsn): Use XML delived from the running instance
[*] # instead of using to_xml(instance, network_info). This is almost
[*] # the ultimate stupid workaround.
[*] if not xml:
[*] xml = virt_dom.XMLDesc(0)
[*]
[*] # NOTE(itoumsn): self.shutdown() and wait instead of self.destroy() is
[*] # better because we cannot ensure flushing dirty buffers
[*] # in the guest OS. But, in case of KVM, shutdown() does not work...
[*] self.destroy(instance, network_info, cleanup=False)
[*] self.plug_vifs(instance, network_info)
[*] self.firewall_driver.setup_basic_filtering(instance, network_info)
[*] self.firewall_driver.prepare_instance_filter(instance, network_info)
[*] self._create_new_domain(xml)
[*] self.firewall_driver.apply_instance_filter(instance, network_info)
[*]
[*] def _wait_for_reboot():
[*] """Called at an interval until the VM is running again."""
[*] instance_name = instance['name']
[*]
[*] try:
[*] state = self.get_info(instance_name)['state']
[*] except exception.NotFound:
[*] msg = _("During reboot, %s disappeared.") % instance_name
[*] LOG.error(msg)
[*] raise utils.LoopingCallDone
[*]
[*] if state == power_state.RUNNING:
[*] msg = _("Instance %s rebooted successfully.") % instance_name
[*] LOG.info(msg)
[*] raise utils.LoopingCallDone
[*]
[*] timer = utils.LoopingCall(_wait_for_reboot)
[*] return timer.start(interval=0.5, now=True)
[*]
[*] @exception.wrap_exception()
[*] def pause(self, instance, callback):
[*] """Pause VM instance"""
[*] dom = self._lookup_by_name(instance.name)
[*] dom.suspend()
[*]
[*] @exception.wrap_exception()
[*] def unpause(self, instance, callback):
[*] """Unpause paused VM instance"""
[*] dom = self._lookup_by_name(instance.name)
[*] dom.resume()
[*]
[*] @exception.wrap_exception()
[*] def suspend(self, instance, callback):
[*] """Suspend the specified instance"""
[*] dom = self._lookup_by_name(instance.name)
[*] dom.managedSave(0)
[*]
[*] @exception.wrap_exception()
[*] def resume(self, instance, callback):
[*] """resume the specified instance"""
[*] dom = self._lookup_by_name(instance.name)
[*] dom.create()
[*]
[*] @exception.wrap_exception()
该文件位于nova/virt/libvirt目录下的connection.py！我只是浅浅的分析了一下类中函数的方法 细节并没有多看，肯定有很多地方是错的 或者不好！希望大家能够帮忙指出错误！ 接下来 看源代码如下：中文部分是我加的注释 ！或许大家会问 为什么要看这个connection.py呢 因为我发现该文件外部virt目录下有个connection.py 其中引用了 这个文件 所以觉得这个应该很重要 而且发现 好多方法都是重写的底层的driver的方法
[*]def rescue(self, context, instance, callback, network_info):
[*] #使用恢复镜像 加载一个vM
[*] """Loads a VM using rescue images.
[*]
[*] A rescue is normally performed when something goes wrong with the
[*] primary images and data needs to be corrected/recovered. Rescuing
[*] should not edit or over-ride the original image, only allow for
[*] data recovery.
[*]
[*] """
[*]
[*] virt_dom = self._conn.lookupByName(instance['name'])
[*] unrescue_xml = virt_dom.XMLDesc(0)
[*] unrescue_xml_path = os.path.join(FLAGS.instances_path,
[*] instance['name'],
[*] 'unrescue.xml')
[*] f = open(unrescue_xml_path, 'w')
[*] f.write(unrescue_xml)
[*] f.close()
[*]
[*] xml = self.to_xml(instance, network_info, rescue=True)
[*] rescue_images = {
[*] 'image_id': FLAGS.rescue_image_id or instance['image_ref'],
[*] 'kernel_id': FLAGS.rescue_kernel_id or instance['kernel_id'],
[*] 'ramdisk_id': FLAGS.rescue_ramdisk_id or instance['ramdisk_id'],
[*] }
[*] self._create_image(context, instance, xml, '.rescue', rescue_images,
[*] network_info=network_info)
[*] self.reboot(instance, network_info, xml=xml)
[*]
[*] @exception.wrap_exception()
[*] def unrescue(self, instance, callback, network_info):
[*] """Reboot the VM which is being rescued back into primary images.
[*]
[*] Because reboot destroys and re-creates instances, unresue should
[*] simply call reboot.
[*]
[*] """
[*] unrescue_xml_path = os.path.join(FLAGS.instances_path,
[*] instance['name'],
[*] 'unrescue.xml')
[*] f = open(unrescue_xml_path)
[*] unrescue_xml = f.read()
[*] f.close()
[*] os.remove(unrescue_xml_path)
[*] self.reboot(instance, network_info, xml=unrescue_xml)
[*]
[*] @exception.wrap_exception()
[*] def poll_rescued_instances(self, timeout):
[*] #轮询已经恢复的实例
[*] pass
[*]
[*] # NOTE(ilyaalekseyev): Implementation like in multinics
[*] # for xenapi(tr3buchet)
[*] @exception.wrap_exception()
[*] def spawn(self, context, instance, network_info,
[*] block_device_info=None):
[*] #感觉像是防火墙的过滤
[*] xml = self.to_xml(instance, network_info, False,
[*] block_device_info=block_device_info)
[*] self.firewall_driver.setup_basic_filtering(instance, network_info)
[*] self.firewall_driver.prepare_instance_filter(instance, network_info)
[*] self._create_image(context, instance, xml, network_info=network_info,
[*] block_device_info=block_device_info)
[*]
[*] domain = self._create_new_domain(xml)
[*] LOG.debug(_("instance %s: is running"), instance['name'])
[*] self.firewall_driver.apply_instance_filter(instance, network_info)
[*]
[*] def _wait_for_boot():
[*] """Called at an interval until the VM is running."""
[*] instance_name = instance['name']
[*]
[*] try:
[*] state = self.get_info(instance_name)['state']
[*] except exception.NotFound:
[*] msg = _("During reboot, %s disappeared.") % instance_name
[*] LOG.error(msg)
[*] raise utils.LoopingCallDone
[*]
[*] if state == power_state.RUNNING:
[*] msg = _("Instance %s spawned successfully.") % instance_name
[*] LOG.info(msg)
[*] raise utils.LoopingCallDone
[*]
[*] timer = utils.LoopingCall(_wait_for_boot)
[*] return timer.start(interval=0.5, now=True)
[*]
[*] def _flush_xen_console(self, virsh_output):
[*] #清除？？
[*] LOG.info(_('virsh said: %r'), virsh_output)
[*] virsh_output = virsh_output.strip()
[*]
[*] if virsh_output.startswith('/dev/'):
[*] LOG.info(_("cool, it's a device"))
[*] out, err = utils.execute('dd',
[*] "if=%s" % virsh_output,
[*] 'iflag=nonblock',
[*] run_as_root=True,
[*] check_exit_code=False)
[*] return out
[*] else:
[*] return ''
[*]
[*] def _append_to_file(self, data, fpath):
[*] #写入fp中 返回fpath
[*] LOG.info(_('data: %(data)r, fpath: %(fpath)r') % locals())
[*] fp = open(fpath, 'a+')
[*] fp.write(data)
[*] return fpath
[*]
[*] def _dump_file(self, fpath):
[*] #返回读出来的contents
[*] fp = open(fpath, 'r+')
[*] contents = fp.read()
[*] LOG.info(_('Contents of file %(fpath)s: %(contents)r') % locals())
[*] return contents
[*]
[*] @exception.wrap_exception()
[*] def get_console_output(self, instance):
[*] #得到控制台的outPut 最后返回的是fpath里面的contents
[*] console_log = os.path.join(FLAGS.instances_path, instance['name'],
[*] 'console.log')
[*]
[*] utils.execute('chown', os.getuid(), console_log, run_as_root=True)
[*]
[*] if FLAGS.libvirt_type == 'xen':
[*] # Xen is special
[*] virsh_output = utils.execute('virsh', 'ttyconsole',
[*] instance['name'])
[*] data = self._flush_xen_console(virsh_output)
[*] fpath = self._append_to_file(data, console_log)
[*] elif FLAGS.libvirt_type == 'lxc':
[*] # LXC is also special
[*] LOG.info(_("Unable to read LXC console"))
[*] else:
[*] fpath = console_log
[*]
[*] return self._dump_file(fpath)
[*]
[*] @exception.wrap_exception()
[*] def get_ajax_console(self, instance):
[*] def get_open_port():
[*] start_port, end_port = FLAGS.ajaxterm_portrange.split("-")
[*] for i in xrange(0, 100):# don't loop forever
[*] port = random.randint(int(start_port), int(end_port))
[*] # netcat will exit with 0 only if the port is in use,
[*] # so a nonzero return value implies it is unused
[*] cmd = 'netcat', '0.0.0.0', port, '-w', '1'
[*] try:
[*] stdout, stderr = utils.execute(*cmd, process_input='')
[*] except exception.ProcessExecutionError:
[*] return port
[*] raise Exception(_('Unable to find an open port'))
[*]
[*] def get_pty_for_instance(instance_name):
[*] virt_dom = self._lookup_by_name(instance_name)
[*] xml = virt_dom.XMLDesc(0)
[*] dom = minidom.parseString(xml)
[*]
[*] for serial in dom.getElementsByTagName('serial'):
[*] if serial.getAttribute('type') == 'pty':
[*] source = serial.getElementsByTagName('source')
[*] return source.getAttribute('path')
[*]
[*] port = get_open_port()
[*] token = str(uuid.uuid4())
[*] host = instance['host']
[*]
[*] ajaxterm_cmd = 'sudo socat - %s' \
[*] % get_pty_for_instance(instance['name'])
[*]
[*] cmd = ['%s/tools/ajaxterm/ajaxterm.py' % utils.novadir(),
[*] '--command', ajaxterm_cmd, '-t', token, '-p', port]
[*]
[*] utils.execute(cmd)
[*] return {'token': token, 'host': host, 'port': port}
[*]
[*] def get_host_ip_addr(self):
[*] # Retrieves the IP address of the dom0得到主机ip地址
[*] return FLAGS.my_ip
[*]
[*] @exception.wrap_exception()
[*] def get_vnc_console(self, instance):
[*] #取得虚拟网络计算机的控制 最后返回 token，host，port
[*] def get_vnc_port_for_instance(instance_name):
[*] virt_dom = self._lookup_by_name(instance_name)
[*] xml = virt_dom.XMLDesc(0)
[*] # TODO: use etree instead of minidom
[*] dom = minidom.parseString(xml)
[*]
[*] for graphic in dom.getElementsByTagName('graphics'):
[*] if graphic.getAttribute('type') == 'vnc':
[*] return graphic.getAttribute('port')
[*]
[*] port = get_vnc_port_for_instance(instance['name'])
[*] token = str(uuid.uuid4())
[*] host = instance['host']
[*]
[*] return {'token': token, 'host': host, 'port': port}
[*]
[*] @staticmethod
[*] def _cache_image(fn, target, fname, cow=False, *args, **kwargs):
[*] #封装一个方法是他能够创建一个可以缓存镜像的镜像
[*] """Wrapper for a method that creates an image that caches the image.
[*]
[*] This wrapper will save the image into a common store and create a
[*] copy for use by the hypervisor.
[*]
[*] The underlying method should specify a kwarg of target representing
[*] where the image will be saved.
[*]
[*] fname is used as the filename of the base image.The filename needs
[*] to be unique to a given image.
[*]
[*] If cow is True, it will make a CoW image instead of a copy.
[*] """
[*]
[*] if not os.path.exists(target):
[*] base_dir = os.path.join(FLAGS.instances_path, '_base')
[*] if not os.path.exists(base_dir):
[*] os.mkdir(base_dir)
[*] base = os.path.join(base_dir, fname)
[*]
[*] @utils.synchronized(fname)
[*] def call_if_not_exists(base, fn, *args, **kwargs):
[*] if not os.path.exists(base):
[*] fn(target=base, *args, **kwargs)
[*]
[*] call_if_not_exists(base, fn, *args, **kwargs)
[*]
[*] if cow:
[*] utils.execute('qemu-img', 'create', '-f', 'qcow2', '-o',
[*] 'cluster_size=2M,backing_file=%s' % base,
[*] target)
[*] else:
[*] utils.execute('cp', base, target)
[*]
[*] def _fetch_image(self, context, target, image_id, user_id, project_id,
[*] size=None):
[*] """Grab image and optionally attempt to resize it"""
[*] #GRAB 镜像和可选地试图调整他
[*] images.fetch_to_raw(context, image_id, target, user_id, project_id)
[*] if size:
[*] disk.extend(target, size)
[*]
[*] def _create_local(self, target, local_size, unit='G', fs_format=None):
[*] """Create a blank image of specified size"""
[*] #创建一个空的指定size的镜像
[*]
[*] if not fs_format:
[*] fs_format = FLAGS.default_local_format
[*]
[*] utils.execute('truncate', target, '-s', "%d%c" % (local_size, unit))
[*] if fs_format:
[*] utils.execute('mkfs', '-t', fs_format, target)
[*]
[*] def _create_ephemeral(self, target, local_size, fs_label, os_type):
[*] self._create_local(target, local_size)
[*] disk.mkfs(os_type, fs_label, target)
[*]
[*] def _create_swap(self, target, swap_mb):
[*] """Create a swap file of specified size"""
[*] #创建一个指定size的swap file
[*] self._create_local(target, swap_mb, unit='M')
[*] utils.execute('mkswap', target)
[*]
[*] def _create_image(self, context, inst, libvirt_xml, suffix='',
[*] disk_images=None, network_info=None,
[*] block_device_info=None):
[*] if not suffix:
[*] suffix = ''
[*]
[*] # syntactic nicety
[*] def basepath(fname='', suffix=suffix):
[*] return os.path.join(FLAGS.instances_path,
[*] inst['name'],
[*] fname + suffix)
[*]
[*] # ensure directories exist and are writable
[*] utils.execute('mkdir', '-p', basepath(suffix=''))
[*]
[*] LOG.info(_('instance %s: Creating image'), inst['name'])
[*] f = open(basepath('libvirt.xml'), 'w')
[*] f.write(libvirt_xml)
[*] f.close()
[*]
[*] if FLAGS.libvirt_type == 'lxc':
[*] container_dir = '%s/rootfs' % basepath(suffix='')
[*] utils.execute('mkdir', '-p', container_dir)
[*]
[*] # NOTE(vish): No need add the suffix to console.log
[*] console_log = basepath('console.log', '')
[*] if os.path.exists(console_log):
[*] utils.execute('chown', os.getuid(), console_log, run_as_root=True)
[*] os.close(os.open(console_log, os.O_CREAT | os.O_WRONLY, 0660))
[*]
[*] if not disk_images:
[*] disk_images = {'image_id': inst['image_ref'],
[*] 'kernel_id': inst['kernel_id'],
[*] 'ramdisk_id': inst['ramdisk_id']}
[*]
[*] if disk_images['kernel_id']:
[*] fname = '%08x' % int(disk_images['kernel_id'])
[*] self._cache_image(fn=self._fetch_image,
[*] context=context,
[*] target=basepath('kernel'),
[*] fname=fname,
[*] image_id=disk_images['kernel_id'],
[*] user_id=inst['user_id'],
[*] project_id=inst['project_id'])
[*] if disk_images['ramdisk_id']:
[*] fname = '%08x' % int(disk_images['ramdisk_id'])
[*] self._cache_image(fn=self._fetch_image,
[*] context=context,
[*] target=basepath('ramdisk'),
[*] fname=fname,
[*] image_id=disk_images['ramdisk_id'],
[*] user_id=inst['user_id'],
[*] project_id=inst['project_id'])
[*]
[*] root_fname = hashlib.sha1(disk_images['image_id']).hexdigest()
[*] size = FLAGS.minimum_root_size
[*]
[*] inst_type_id = inst['instance_type_id']
[*] inst_type = instance_types.get_instance_type(inst_type_id)
[*] if inst_type['name'] == 'm1.tiny' or suffix == '.rescue':
[*] size = None
[*] root_fname += "_sm"
[*]
[*] if not self._volume_in_mapping(self.default_root_device,
[*] block_device_info):
[*] self._cache_image(fn=self._fetch_image,
[*] context=context,
[*] target=basepath('disk'),
[*] fname=root_fname,
[*] cow=FLAGS.use_cow_images,
[*] image_id=disk_images['image_id'],
[*] user_id=inst['user_id'],
[*] project_id=inst['project_id'],
[*] size=size)
[*]
[*] local_gb = inst['local_gb']
[*] if local_gb and not self._volume_in_mapping(
[*] self.default_local_device, block_device_info):
[*] fn = functools.partial(self._create_ephemeral,
[*] fs_label='ephemeral0',
[*] os_type=inst.os_type)
[*] self._cache_image(fn=fn,
[*] target=basepath('disk.local'),
[*] fname="ephemeral_%s_%s_%s" %
[*] ("0", local_gb, inst.os_type),
[*] cow=FLAGS.use_cow_images,
[*] local_size=local_gb)
[*]
[*] for eph in driver.block_device_info_get_ephemerals(block_device_info):
[*] fn = functools.partial(self._create_ephemeral,
[*] fs_label='ephemeral%d' % eph['num'],
[*] os_type=inst.os_type)
[*] self._cache_image(fn=fn,
[*] target=basepath(_get_eph_disk(eph)),
[*] fname="ephemeral_%s_%s_%s" %
[*] (eph['num'], eph['size'], inst.os_type),
[*] cow=FLAGS.use_cow_images,
[*] local_size=eph['size'])
[*]
[*] swap_mb = 0
[*]
[*] swap = driver.block_device_info_get_swap(block_device_info)
[*] if driver.swap_is_usable(swap):
[*] swap_mb = swap['swap_size']
[*] elif (inst_type['swap'] > 0 and
[*] not self._volume_in_mapping(self.default_swap_device,
[*] block_device_info)):
[*] swap_mb = inst_type['swap']
[*]
[*] if swap_mb > 0:
[*] self._cache_image(fn=self._create_swap,
[*] target=basepath('disk.swap'),
[*] fname="swap_%s" % swap_mb,
[*] cow=FLAGS.use_cow_images,
[*] swap_mb=swap_mb)
[*]
[*] # For now, we assume that if we're not using a kernel, we're using a
[*] # partitioned disk image where the target partition is the first
[*] # partition
[*] target_partition = None
[*] if not inst['kernel_id']:
[*] target_partition = "1"
[*]
[*] config_drive_id = inst.get('config_drive_id')
[*] config_drive = inst.get('config_drive')
[*]
[*] if any((FLAGS.libvirt_type == 'lxc', config_drive, config_drive_id)):
[*] target_partition = None
[*]
[*] if config_drive_id:
[*] fname = '%08x' % int(config_drive_id)
[*] self._cache_image(fn=self._fetch_image,
[*] target=basepath('disk.config'),
[*] fname=fname,
[*] image_id=config_drive_id,
[*] user_id=inst['user_id'],
[*] project_id=inst['project_id'],)
[*] elif config_drive:
[*] self._create_local(basepath('disk.config'), 64, unit='M',
[*] fs_format='msdos')# 64MB
[*]
[*] if inst['key_data']:
[*] key = str(inst['key_data'])
[*] else:
[*] key = None
[*] net = None
[*]
[*] nets = []
[*] ifc_template = open(FLAGS.injected_network_template).read()
[*] ifc_num = -1
[*] have_injected_networks = False
[*] admin_context = nova_context.get_admin_context()
[*] for (network_ref, mapping) in network_info:
[*] ifc_num += 1
[*]
[*] if not network_ref['injected']:
[*] continue
[*]
[*] have_injected_networks = True
[*] address = mapping['ips']['ip']
[*] netmask = mapping['ips']['netmask']
[*] address_v6 = None
[*] gateway_v6 = None
[*] netmask_v6 = None
[*] if FLAGS.use_ipv6:
[*] address_v6 = mapping['ip6s']['ip']
[*] netmask_v6 = mapping['ip6s']['netmask']
[*] gateway_v6 = mapping['gateway6']
[*] net_info = {'name': 'eth%d' % ifc_num,
[*] 'address': address,
[*] 'netmask': netmask,
[*] 'gateway': mapping['gateway'],
[*] 'broadcast': mapping['broadcast'],
[*] 'dns': ' '.join(mapping['dns']),
[*] 'address_v6': address_v6,
[*] 'gateway6': gateway_v6,
[*] 'netmask_v6': netmask_v6}
[*] nets.append(net_info)
[*]
[*] if have_injected_networks:
[*] net = str(Template(ifc_template,
[*] searchList=[{'interfaces': nets,
[*] 'use_ipv6': FLAGS.use_ipv6}]))
[*]
[*] metadata = inst.get('metadata')
[*] if any((key, net, metadata)):
[*] inst_name = inst['name']
[*]
[*] if config_drive:# Should be True or None by now.
[*] injection_path = basepath('disk.config')
[*] img_id = 'config-drive'
[*] tune2fs = False
[*] else:
[*] injection_path = basepath('disk')
[*] img_id = inst.image_ref
[*] tune2fs = True
[*]
[*] for injection in ('metadata', 'key', 'net'):
[*] if locals():
[*] LOG.info(_('instance %(inst_name)s: injecting '
[*] '%(injection)s into image %(img_id)s'
[*] % locals()))
[*] try:
[*] disk.inject_data(injection_path, key, net, metadata,
[*] partition=target_partition,
[*] nbd=FLAGS.use_cow_images,
[*] tune2fs=tune2fs)
[*]
[*] except Exception as e:
[*] # This could be a windows image, or a vmdk format disk
[*] LOG.warn(_('instance %(inst_name)s: ignoring error injecting'
[*] ' data into image %(img_id)s (%(e)s)') % locals())
[*]
[*] if FLAGS.libvirt_type == 'lxc':
[*] disk.setup_container(basepath('disk'),
[*] container_dir=container_dir,
[*] nbd=FLAGS.use_cow_images)
[*]
[*] if FLAGS.libvirt_type == 'uml':
[*] utils.execute('chown', 'root', basepath('disk'), run_as_root=True)
该文件位于nova/virt/libvirt目录下的connection.py！我只是浅浅的分析了一下类中函数的方法 细节并没有多看，肯定有很多地方是错的 或者不好！希望大家能够帮忙指出错误！ 接下来 看源代码如下：中文部分是我加的注释 ！或许大家会问 为什么要看这个connection.py呢 因为我发现该文件外部virt目录下有个connection.py 其中引用了 这个文件 所以觉得这个应该很重要 而且发现 好多方法都是重写的底层的driver的方法
[*]if FLAGS.libvirt_type == 'uml':
[*] _disk_prefix = 'ubd'
[*] elif FLAGS.libvirt_type == 'xen':
[*] _disk_prefix = 'sd'
[*] elif FLAGS.libvirt_type == 'lxc':
[*] _disk_prefix = ''
[*] else:
[*] _disk_prefix = 'vd'
[*]
[*] default_root_device = _disk_prefix + 'a'
[*] default_local_device = _disk_prefix + 'b'
[*] default_swap_device = _disk_prefix + 'c'
[*]
[*] def _volume_in_mapping(self, mount_device, block_device_info):
[*] block_device_list = )
[*] for vol in
[*] driver.block_device_info_get_mapping(
[*] block_device_info)]
[*] swap = driver.block_device_info_get_swap(block_device_info)
[*] if driver.swap_is_usable(swap):
[*] block_device_list.append(
[*] block_device.strip_dev(swap['device_name']))
[*] block_device_list += )
[*] for ephemeral in
[*] driver.block_device_info_get_ephemerals(
[*] block_device_info)]
[*]
[*] LOG.debug(_("block_device_list %s"), block_device_list)
[*] return block_device.strip_dev(mount_device) in block_device_list
[*]
[*] def _get_volume_device_info(self, device_path):
[*] if device_path.startswith('/dev/'):
[*] return ('block', None, None)
[*] elif ':' in device_path:
[*] (protocol, name) = device_path.split(':')
[*] return ('network', protocol, name)
[*] else:
[*] raise exception.InvalidDevicePath(path=device_path)
[*]
[*] def _prepare_xml_info(self, instance, network_info, rescue,
[*] block_device_info=None):
[*] #感觉是返回的xml的信息
[*] block_device_mapping = driver.block_device_info_get_mapping(
[*] block_device_info)
[*]
[*] nics = []
[*] for (network, mapping) in network_info:
[*] nics.append(self.vif_driver.plug(instance, network, mapping))
[*] # FIXME(vish): stick this in db
[*] inst_type_id = instance['instance_type_id']
[*] inst_type = instance_types.get_instance_type(inst_type_id)
[*]
[*] if FLAGS.use_cow_images:
[*] driver_type = 'qcow2'
[*] else:
[*] driver_type = 'raw'
[*]
[*] for vol in block_device_mapping:
[*] vol['mount_device'] = block_device.strip_dev(vol['mount_device'])
[*] (vol['type'], vol['protocol'], vol['name']) = \
[*] self._get_volume_device_info(vol['device_path'])
[*]
[*] ebs_root = self._volume_in_mapping(self.default_root_device,
[*] block_device_info)
[*]
[*] local_device = False
[*] if not (self._volume_in_mapping(self.default_local_device,
[*] block_device_info) or
[*] 0 in for eph in
[*] driver.block_device_info_get_ephemerals(
[*] block_device_info)]):
[*] if instance['local_gb'] > 0:
[*] local_device = self.default_local_device
[*]
[*] ephemerals = []
[*] for eph in driver.block_device_info_get_ephemerals(block_device_info):
[*] ephemerals.append({'device_path': _get_eph_disk(eph),
[*] 'device': block_device.strip_dev(
[*] eph['device_name'])})
[*]
[*] xml_info = {'type': FLAGS.libvirt_type,
[*] 'name': instance['name'],
[*] 'basepath': os.path.join(FLAGS.instances_path,
[*] instance['name']),
[*] 'memory_kb': inst_type['memory_mb'] * 1024,
[*] 'vcpus': inst_type['vcpus'],
[*] 'rescue': rescue,
[*] 'disk_prefix': self._disk_prefix,
[*] 'driver_type': driver_type,
[*] 'vif_type': FLAGS.libvirt_vif_type,
[*] 'nics': nics,
[*] 'ebs_root': ebs_root,
[*] 'local_device': local_device,
[*] 'volumes': block_device_mapping,
[*] 'use_virtio_for_bridges':
[*] FLAGS.libvirt_use_virtio_for_bridges,
[*] 'ephemerals': ephemerals}
[*]
[*] root_device_name = driver.block_device_info_get_root(block_device_info)
[*] if root_device_name:
[*] xml_info['root_device'] = block_device.strip_dev(root_device_name)
[*] xml_info['root_device_name'] = root_device_name
[*] else:
[*] # NOTE(yamahata):
[*] # for nova.api.ec2.cloud.CloudController.get_metadata()
[*] xml_info['root_device'] = self.default_root_device
[*] db.instance_update(
[*] nova_context.get_admin_context(), instance['id'],
[*] {'root_device_name': '/dev/' + self.default_root_device})
[*]
[*] if local_device:
[*] db.instance_update(
[*] nova_context.get_admin_context(), instance['id'],
[*] {'default_local_device': '/dev/' + self.default_local_device})
[*]
[*] swap = driver.block_device_info_get_swap(block_device_info)
[*] if driver.swap_is_usable(swap):
[*] xml_info['swap_device'] = block_device.strip_dev(
[*] swap['device_name'])
[*] elif (inst_type['swap'] > 0 and
[*] not self._volume_in_mapping(self.default_swap_device,
[*] block_device_info)):
[*] xml_info['swap_device'] = self.default_swap_device
[*] db.instance_update(
[*] nova_context.get_admin_context(), instance['id'],
[*] {'default_swap_device': '/dev/' + self.default_swap_device})
[*]
[*] config_drive = False
[*] if instance.get('config_drive') or instance.get('config_drive_id'):
[*] xml_info['config_drive'] = xml_info['basepath'] + "/disk.config"
[*]
[*] if FLAGS.vnc_enabled and FLAGS.libvirt_type not in ('lxc', 'uml'):
[*] xml_info['vncserver_host'] = FLAGS.vncserver_host
[*] xml_info['vnc_keymap'] = FLAGS.vnc_keymap
[*] if not rescue:
[*] if instance['kernel_id']:
[*] xml_info['kernel'] = xml_info['basepath'] + "/kernel"
[*]
[*] if instance['ramdisk_id']:
[*] xml_info['ramdisk'] = xml_info['basepath'] + "/ramdisk"
[*]
[*] xml_info['disk'] = xml_info['basepath'] + "/disk"
[*] return xml_info
[*]
[*] def to_xml(self, instance, network_info, rescue=False,
[*] block_device_info=None):
[*] # TODO(termie): cache?
[*] LOG.debug(_('instance %s: starting toXML method'), instance['name'])
[*] xml_info = self._prepare_xml_info(instance, network_info, rescue,
[*] block_device_info)
[*] xml = str(Template(self.libvirt_xml, searchList=))
[*] LOG.debug(_('instance %s: finished toXML method'), instance['name'])
[*] return xml
[*]
[*] def _lookup_by_name(self, instance_name):
[*] #检索libvirt（授权）域对象 给定一个实例名 所有的 libvirt错误在这个 方法中 都应该有被处理的handler
[*] """Retrieve libvirt domain object given an instance name.
[*]
[*]
[*] All libvirt error handling should be handled in this method and
[*] relevant nova exceptions should be raised in response.
[*]
[*] """
[*] try:
[*] return self._conn.lookupByName(instance_name)
[*] except libvirt.libvirtError as ex:
[*] error_code = ex.get_error_code()
[*] if error_code == libvirt.VIR_ERR_NO_DOMAIN:
[*] raise exception.InstanceNotFound(instance_id=instance_name)
[*]
[*] msg = _("Error from libvirt while looking up %(instance_name)s: "
[*] " %(ex)s") % locals()
[*] raise exception.Error(msg)
[*]
[*] def get_info(self, instance_name):
[*] #为了一个特定的实例名从libvirt中检索信息 返回一个 字典
[*] """Retrieve information from libvirt for a specific instance name.
[*]
[*] If a libvirt error is encountered during lookup, we might raise a
[*] NotFound exception or Error exception depending on how severe the
[*] libvirt error is.
[*]
[*] """
[*] virt_dom = self._lookup_by_name(instance_name)
[*] (state, max_mem, mem, num_cpu, cpu_time) = virt_dom.info()
[*] return {'state': state,
[*] 'max_mem': max_mem,
[*] 'mem': mem,
[*] 'num_cpu': num_cpu,
[*] 'cpu_time': cpu_time}
[*]
[*] def _create_new_domain(self, xml, persistent=True, launch_flags=0):
[*] #创建一个新的域 返回值是domain
[*] # NOTE(justinsb): libvirt has two types of domain:
[*] # * a transient domain disappears when the guest is shutdown
[*] # or the host is rebooted.
[*] # * a permanent domain is not automatically deleted
[*] # NOTE(justinsb): Even for ephemeral instances, transient seems risky
[*]
[*] if persistent:
[*] # To create a persistent domain, first define it, then launch it.
[*] domain = self._conn.defineXML(xml)
[*]
[*] domain.createWithFlags(launch_flags)
[*] else:
[*] # createXML call creates a transient domain
[*] domain = self._conn.createXML(xml, launch_flags)
[*]
[*] return domain
[*]
[*] def get_diagnostics(self, instance_name):
[*] #诊断？
[*] raise exception.ApiError(_("diagnostics are not supported "
[*] "for libvirt"))
[*]
[*] def get_disks(self, instance_name):
[*] #该函数接受一个实例名 作为参数 最后对于该域返回一个所有块devices的列表
[*] """
[*] Note that this function takes an instance name.
[*]
[*] Returns a list of all block devices for this domain.
[*] """
[*] domain = self._lookup_by_name(instance_name)
[*] # TODO(devcamcar): Replace libxml2 with etree.
[*] xml = domain.XMLDesc(0)
[*] doc = None
[*]
[*] try:
[*] doc = libxml2.parseDoc(xml)
[*] except Exception:
[*] return []
[*]
[*] ctx = doc.xpathNewContext()
[*] disks = []
[*]
[*] try:
[*] ret = ctx.xpathEval('/domain/devices/disk')
[*]
[*] for node in ret:
[*] devdst = None
[*]
[*] for child in node.children:
[*] if child.name == 'target':
[*] devdst = child.prop('dev')
[*]
[*] if devdst is None:
[*] continue
[*]
[*] disks.append(devdst)
[*] finally:
[*] if ctx is not None:
[*] ctx.xpathFreeContext()
[*] if doc is not None:
[*] doc.freeDoc()
[*]
[*] return disks
[*]
[*] def get_interfaces(self, instance_name):
[*] #该函数同样 接受一个 实例名作为参数 最后对于该 实例返回一个所有network interface的 列表
[*] """
[*] Note that this function takes an instance name.
[*]
[*] Returns a list of all network interfaces for this instance.
[*] """
[*] domain = self._lookup_by_name(instance_name)
[*] # TODO(devcamcar): Replace libxml2 with etree.
[*] xml = domain.XMLDesc(0)
[*] doc = None
[*]
[*] try:
[*] doc = libxml2.parseDoc(xml)
[*] except Exception:
[*] return []
[*]
[*] ctx = doc.xpathNewContext()
[*] interfaces = []
[*]
[*] try:
[*] ret = ctx.xpathEval('/domain/devices/interface')
[*]
[*] for node in ret:
[*] devdst = None
[*]
[*] for child in node.children:
[*] if child.name == 'target':
[*] devdst = child.prop('dev')
[*]
[*] if devdst is None:
[*] continue
[*]
[*] interfaces.append(devdst)
[*] finally:
[*] if ctx is not None:
[*] ctx.xpathFreeContext()
[*] if doc is not None:
[*] doc.freeDoc()
[*]
[*] return interfaces
[*]
[*] def get_vcpu_total(self):
[*] #得到虚拟处理器物理computermb 最后返回核心cpu的数量？
[*] """Get vcpu nuer of physical computermb.
[*]
[*] :returns: the number of cpu core.
[*]
[*] """
[*]
[*] # On certain platforms, this will raise a NotImplementedError.
[*] try:
[*] return multiprocessing.cpu_count()
[*] except NotImplementedError:
[*] LOG.warn(_("Cannot get the number of cpu, because this "
[*] "function is not implemented for this platform. "
[*] "This error can be safely ignored for now."))
[*] return 0
[*]
[*] def get_memory_mb_total(self):
[*]# 得到 总的物理电脑的内存 返回 总共的memory(MB)
[*] """Get the total memory size(MB) of physical computer.
[*]
[*] :returns: the total amount of memory(MB).
[*]
[*] """
[*]
[*] if sys.platform.upper() != 'LINUX2':
[*] return 0
[*]
[*] meminfo = open('/proc/meminfo').read().split()
[*] idx = meminfo.index('MemTotal:')
[*] # transforming kb to mb.
[*] return int(meminfo) / 1024
[*]
[*] def get_local_gb_total(self):
[*]#得到 总的硬盘驱动器的size 返回 总size 注意该值显示一个 实例挂载点分区的值
[*] """Get the total hdd size(GB) of physical computer.
[*]
[*] :returns:
[*] The total amount of HDD(GB).
[*] Note that this value shows a partition where
[*] NOVA-INST-DIR/instances mounts.
[*]
[*] """
[*]
[*] hddinfo = os.statvfs(FLAGS.instances_path)
[*] return hddinfo.f_frsize * hddinfo.f_blocks / 1024 / 1024 / 1024
[*]
[*] def get_vcpu_used(self):
[*]#得到一个可用 的物理电脑的虚拟处理器的number 最后返回当前用的total number of vcpu
[*] """ Get vcpu usage number of physical computer.
[*]
[*] :returns: The total number of vcpu that currently used.
[*]
[*] """
[*]
[*] total = 0
[*] for dom_id in self._conn.listDomainsID():
[*] dom = self._conn.lookupByID(dom_id)
[*] total += len(dom.vcpus())
[*] return total
[*]
[*] def get_memory_mb_used(self):
[*]#得到物理计算机free内存大小 返回total usage内存（总使用）
[*] """Get the free memory size(MB) of physical computer.
[*]
[*] :returns: the total usage of memory(MB).
[*]
[*] """
[*]
[*] if sys.platform.upper() != 'LINUX2':
[*] return 0
[*]
[*] m = open('/proc/meminfo').read().split()
[*] idx1 = m.index('MemFree:')
[*] idx2 = m.index('Buffers:')
[*] idx3 = m.index('Cached:')
[*] avail = (int(m) + int(m) + int(m)) / 1024
[*] returnself.get_memory_mb_total() - avail
[*]
[*] def get_local_gb_used(self):
[*] #得到物理计算机（硬盘驱动器）free内存大小 返回total usage内存（总使用）
[*] """Get the free hdd size(GB) of physical computer.
[*]
[*] :returns:
[*] The total usage of HDD(GB).
[*] Note that this value shows a partition where
[*] NOVA-INST-DIR/instances mounts.
[*]
[*] """
[*]
[*] hddinfo = os.statvfs(FLAGS.instances_path)
[*] avail = hddinfo.f_frsize * hddinfo.f_bavail / 1024 / 1024 / 1024
[*] return self.get_local_gb_total() - avail
[*]
[*] def get_hypervisor_type(self):
[*]#得到管理程序的类型 最后返回 一个类型
[*] """Get hypervisor type.
[*]
[*] :returns: hypervisor type (ex. qemu)
[*]
[*] """
[*]
[*] return self._conn.getType()
[*]
[*] def get_hypervisor_version(self):
[*]#得到版本 返回版本
[*] """Get hypervisor version.
[*]
[*] :returns: hypervisor version (ex. 12003)
[*]
[*] """
[*]
[*] # NOTE(justinsb): getVersion moved between libvirt versions
[*] # Trying to do be compatible with older versions is a lost cause
[*] # But ... we can at least give the user a nice message
[*] method = getattr(self._conn, 'getVersion', None)
[*] if method is None:
[*] raise exception.Error(_("libvirt version is too old"
[*] " (does not support getVersion)"))
[*] # NOTE(justinsb): If we wanted to get the version, we could:
[*] # method = getattr(libvirt, 'getVersion', None)
[*] # NOTE(justinsb): This would then rely on a proper version check
[*]
[*] return method()
由于该文件大于8万字符 所以我分4次挂载(4
[*] def get_cpu_info(self):
[*]#获取cpuinfd 的信息 返回utils.dumps(cpu_info)
[*]
[*] """Get cpuinfo information.
[*]
[*] Obtains cpu feature from virConnect.getCapabilities,
[*] and returns as a json string.
[*]
[*] :return: see above description
[*]
[*] """
[*]
[*] xml = self._conn.getCapabilities()
[*] xml = libxml2.parseDoc(xml)
[*] nodes = xml.xpathEval('//host/cpu')
[*] if len(nodes) != 1:
[*] reason = _("'<cpu>' must be 1, but %d\n") % len(nodes)
[*] reason += xml.serialize()
[*] raise exception.InvalidCPUInfo(reason=reason)
[*]
[*] cpu_info = dict()
[*]
[*] arch_nodes = xml.xpathEval('//host/cpu/arch')
[*] if arch_nodes:
[*] cpu_info['arch'] = arch_nodes.getContent()
[*]
[*] model_nodes = xml.xpathEval('//host/cpu/model')
[*] if model_nodes:
[*] cpu_info['model'] = model_nodes.getContent()
[*]
[*] vendor_nodes = xml.xpathEval('//host/cpu/vendor')
[*] if vendor_nodes:
[*] cpu_info['vendor'] = vendor_nodes.getContent()
[*]
[*] topology_nodes = xml.xpathEval('//host/cpu/topology')
[*] topology = dict()
[*] if topology_nodes:
[*] topology_node = topology_nodes.get_properties()
[*] while topology_node:
[*] name = topology_node.get_name()
[*] topology = topology_node.getContent()
[*] topology_node = topology_node.get_next()
[*]
[*] keys = ['cores', 'sockets', 'threads']
[*] tkeys = topology.keys()
[*] if set(tkeys) != set(keys):
[*] ks = ', '.join(keys)
[*] reason = _("topology (%(topology)s) must have %(ks)s")
[*] raise exception.InvalidCPUInfo(reason=reason % locals())
[*]
[*] feature_nodes = xml.xpathEval('//host/cpu/feature')
[*] features = list()
[*] for nodes in feature_nodes:
[*] features.append(nodes.get_properties().getContent())
[*]
[*] cpu_info['topology'] = topology
[*] cpu_info['features'] = features
[*] return utils.dumps(cpu_info)
[*]
[*] def block_stats(self, instance_name, disk):
[*]#接受实例名为参数 返回一个domain.blockStats(disk) 应该是域所在磁盘的一个状态？？
[*] """
[*] Note that this function takes an instance name.
[*] """
[*] domain = self._lookup_by_name(instance_name)
[*] return domain.blockStats(disk)
[*]
[*] def interface_stats(self, instance_name, interface):
[*]#接受实例名为参数 返回一个domain.interfanceStats(interface) 应该是域所在interface的一个状态
[*] """
[*] Note that this function takes an instance name.
[*] """
[*] domain = self._lookup_by_name(instance_name)
[*] return domain.interfaceStats(interface)
[*]
[*] def get_console_pool_info(self, console_type):
[*]#返回控制池的信息 （给出的一个fake data） ip username password
[*] #TODO(mdragon): console proxy should be implemented for libvirt,
[*] # in case someone wants to use it with kvm or
[*] # such. For now return fake data.
[*] return{'address': '127.0.0.1',
[*] 'username': 'fakeuser',
[*] 'password': 'fakepassword'}
[*]
[*] def refresh_security_group_rules(self, security_group_id):
[*] self.firewall_driver.refresh_security_group_rules(security_group_id)
[*]
[*] def refresh_security_group_members(self, security_group_id):
[*] self.firewall_driver.refresh_security_group_members(security_group_id)
[*]
[*] def refresh_provider_fw_rules(self):
[*] self.firewall_driver.refresh_provider_fw_rules()
[*]
[*] def update_available_resource(self, ctxt, host):
[*]#在电脑节点表中更新电脑管理资源的信息 这是一个很重要的函数 当nova-computer 登陆的时候 执行nova-manage serverce ..
[*] """Updates compute manager resource info on ComputeNode table.
[*]
[*] This method is called when nova-coompute launches, and
[*] whenever admin executes "nova-manage service update_resource".
[*]
[*] :param ctxt: security context
[*] :param host: hostname that compute manager is currently running
[*]
[*] """
[*]
[*] try:
[*] service_ref = db.service_get_all_compute_by_host(ctxt, host)
[*] except exception.NotFound:
[*] raise exception.ComputeServiceUnavailable(host=host)
[*]
[*] # Updating host information
[*] dic = {'vcpus': self.get_vcpu_total(),
[*] 'memory_mb': self.get_memory_mb_total(),
[*] 'local_gb': self.get_local_gb_total(),
[*] 'vcpus_used': self.get_vcpu_used(),
[*] 'memory_mb_used': self.get_memory_mb_used(),
[*] 'local_gb_used': self.get_local_gb_used(),
[*] 'hypervisor_type': self.get_hypervisor_type(),
[*] 'hypervisor_version': self.get_hypervisor_version(),
[*] 'cpu_info': self.get_cpu_info()}
[*]
[*] compute_node_ref = service_ref['compute_node']
[*] if not compute_node_ref:
[*] LOG.info(_('Compute_service record created for %s ') % host)
[*] dic['service_id'] = service_ref['id']
[*] db.compute_node_create(ctxt, dic)
[*] else:
[*] LOG.info(_('Compute_service record updated for %s ') % host)
[*] db.compute_node_update(ctxt, compute_node_ref['id'], dic)
[*]
[*] def compare_cpu(self, cpu_info):
[*]#检查给出xml是否和主机cpu兼容 xml”必须是一个libvirt.openReadonly的一部分().getCapabilities()
[*]#返回值follows by virCPUCompareResult。
[*] #如果0 >返回值,做动态迁移。
[*]#返回： 如果给定cpu信息与该服务器并不兼容, 抛出异常。
[*]
[*] """Checks the host cpu is compatible to a cpu given by xml.
[*]
[*] "xml" must be a part of libvirt.openReadonly().getCapabilities().
[*] return values follows by virCPUCompareResult.
[*] if 0 > return value, do live migration.
[*] 'http://libvirt.org/html/libvirt-libvirt.html#virCPUCompareResult'
[*]
[*] :param cpu_info: json string that shows cpu feature(see get_cpu_info())
[*] :returns:
[*] None. if given cpu info is not compatible to this server,
[*] raise exception.
[*]
[*] """
[*]
[*] LOG.info(_('Instance launched has CPU info:\n%s') % cpu_info)
[*] dic = utils.loads(cpu_info)
[*] xml = str(Template(self.cpuinfo_xml, searchList=dic))
[*] LOG.info(_('to xml...\n:%s ' % xml))
[*]
[*] u = "http://libvirt.org/html/libvirt-libvirt.html#virCPUCompareResult"
[*] m = _("CPU doesn't have compatibility.\n\n%(ret)s\n\nRefer to %(u)s")
[*] # unknown character exists in xml, then libvirt complains
[*] try:
[*] ret = self._conn.compareCPU(xml, 0)
[*] except libvirt.libvirtError, e:
[*] ret = e.message
[*] LOG.error(m % locals())
[*] raise
[*]
[*] if ret <= 0:
[*] raise exception.InvalidCPUInfo(reason=m % locals())
[*]
[*] return
[*]
[*] def ensure_filtering_rules_for_instance(self, instance_ref, network_info,
[*] time=None):
[*] #不知道大家注意没 上面这些 好多都是重写driver.py中的方法
[*] #设置过滤规则,并等待它完成
[*] """Setting up filtering rules and waiting for its completion.
[*]
[*] To migrate an instance, filtering rules to hypervisors
[*] and firewalls are inevitable on destination host.
[*] ( Waiting only for filterling rules to hypervisor,
[*] since filtering rules to firewall rules can be set faster).
[*]
[*] Concretely, the below method must be called.
[*] - setup_basic_filtering (for nova-basic, etc.)
[*] - prepare_instance_filter(for nova-instance-instance-xxx, etc.)
[*]
[*] to_xml may have to be called since it defines PROJNET, PROJMASK.
[*] but libvirt migrates those value through migrateToURI(),
[*] so , no need to be called.
[*]
[*] Don't use thread for this method since migration should
[*] not be started when setting-up filtering rules operations
[*] are not completed.
[*]
[*] :params instance_ref: nova.db.sqlalchemy.models.Instance object
[*]
[*] """
[*]
[*] if not time:
[*] time = greenthread
[*]
[*] # If any instances never launch at destination host,
[*] # basic-filtering must be set here.
[*] self.firewall_driver.setup_basic_filtering(instance_ref, network_info)
[*] # setting up nova-instance-instance-xx mainly.
[*] self.firewall_driver.prepare_instance_filter(instance_ref,
[*] network_info)
[*]
[*] # wait for completion
[*] timeout_count = range(FLAGS.live_migration_retry_count)
[*] while timeout_count:
[*] if self.firewall_driver.instance_filter_exists(instance_ref,
[*] network_info):
[*] break
[*] timeout_count.pop()
[*] if len(timeout_count) == 0:
[*] msg = _('Timeout migrating for %s. nwfilter not found.')
[*] raise exception.Error(msg % instance_ref.name)
[*] time.sleep(1)
[*]
[*] def live_migration(self, ctxt, instance_ref, dest,
[*] post_method, recover_method, block_migration=False):
[*] #分发处理高负荷，当有高负荷操作时候，大量生成 live_mirgration
[*] """Spawning live_migration operation for distributing high-load.
[*]
[*] :params ctxt: security context
[*] :params instance_ref:
[*] nova.db.sqlalchemy.models.Instance object
[*] instance object that is migrated.
[*] :params dest: destination host
[*] :params block_migration: destination host
[*] :params post_method:
[*] post operation method.
[*] expected nova.compute.manager.post_live_migration.
[*] :params recover_method:
[*] recovery method when any exception occurs.
[*] expected nova.compute.manager.recover_live_migration.
[*] :params block_migration: if true, do block migration.
[*]
[*] """
[*]
[*] greenthread.spawn(self._live_migration, ctxt, instance_ref, dest,
[*] post_method, recover_method, block_migration)
[*]
[*] def _live_migration(self, ctxt, instance_ref, dest, post_method,
[*] recover_method, block_migration=False):
[*] #动态迁移？？？
[*] """Do live migration.
[*]
[*] :params ctxt: security context
[*] :params instance_ref:
[*] nova.db.sqlalchemy.models.Instance object
[*] instance object that is migrated.
[*] :params dest: destination host
[*] :params post_method:
[*] post operation method.
[*] expected nova.compute.manager.post_live_migration.
[*] :params recover_method:
[*] recovery method when any exception occurs.
[*] expected nova.compute.manager.recover_live_migration.
[*]
[*] """
[*]
[*] # Do live migration.
[*] try:
[*] if block_migration:
[*] flaglist = FLAGS.block_migration_flag.split(',')
[*] else:
[*] flaglist = FLAGS.live_migration_flag.split(',')
[*] flagvals =
[*] logical_sum = reduce(lambda x, y: x | y, flagvals)
[*]
[*] dom = self._conn.lookupByName(instance_ref.name)
[*] dom.migrateToURI(FLAGS.live_migration_uri % dest,
[*] logical_sum,
[*] None,
[*] FLAGS.live_migration_bandwidth)
[*]
[*] except Exception:
[*] recover_method(ctxt, instance_ref, dest, block_migration)
[*] raise
[*]
[*] # Waiting for completion of live_migration.
[*] timer = utils.LoopingCall(f=None)
[*]
[*] def wait_for_live_migration():
[*] """waiting for live migration completion"""
[*] try:
[*] self.get_info(instance_ref.name)['state']
[*] except exception.NotFound:
[*] timer.stop()
[*] post_method(ctxt, instance_ref, dest, block_migration)
[*]
[*] timer.f = wait_for_live_migration
[*] timer.start(interval=0.5, now=True)
[*]
[*] def pre_block_migration(self, ctxt, instance_ref, disk_info_json):
[*]#准备block的 迁移
[*] """Preparation block migration.
[*]
[*] :params ctxt: security context
[*] :params instance_ref:
[*] nova.db.sqlalchemy.models.Instance object
[*] instance object that is migrated.
[*] :params disk_info_json:
[*] json strings specified in get_instance_disk_info
[*]
[*] """
[*] disk_info = utils.loads(disk_info_json)
[*]
[*] # make instance directory
[*] instance_dir = os.path.join(FLAGS.instances_path, instance_ref['name'])
[*] if os.path.exists(instance_dir):
[*] raise exception.DestinationDiskExists(path=instance_dir)
[*] os.mkdir(instance_dir)
[*]
[*] for info in disk_info:
[*] base = os.path.basename(info['path'])
[*] # Get image type and create empty disk image.
[*] instance_disk = os.path.join(instance_dir, base)
[*] utils.execute('qemu-img', 'create', '-f', info['type'],
[*] instance_disk, info['local_gb'])
[*]
[*] # if image has kernel and ramdisk, just download
[*] # following normal way.
[*] if instance_ref['kernel_id']:
[*] user = manager.AuthManager().get_user(instance_ref['user_id'])
[*] project = manager.AuthManager().get_project(
[*] instance_ref['project_id'])
[*] self._fetch_image(nova_context.get_admin_context(),
[*] os.path.join(instance_dir, 'kernel'),
[*] instance_ref['kernel_id'],
[*] user,
[*] project)
[*] if instance_ref['ramdisk_id']:
[*] self._fetch_image(nova_context.get_admin_context(),
[*] os.path.join(instance_dir, 'ramdisk'),
[*] instance_ref['ramdisk_id'],
[*] user,
[*] project)
[*]
[*] def post_live_migration_at_destination(self, ctxt,
[*] instance_ref,
[*] network_info,
[*] block_migration):
[*] #Post操作的动态迁移到目的地主机
[*] """Post operation of live migration at destination host.
[*]
[*] :params ctxt: security context
[*] :params instance_ref:
[*] nova.db.sqlalchemy.models.Instance object
[*] instance object that is migrated.
[*] :params network_info: instance network infomation
[*] :params : block_migration: if true, post operation of block_migraiton.
[*] """
[*] # Define migrated instance, otherwise, suspend/destroy does not work.
[*] dom_list = self._conn.listDefinedDomains()
[*] if instance_ref.name not in dom_list:
[*] instance_dir = os.path.join(FLAGS.instances_path,
[*] instance_ref.name)
[*] xml_path = os.path.join(instance_dir, 'libvirt.xml')
[*] # In case of block migration, destination does not have
[*] # libvirt.xml
[*] if not os.path.isfile(xml_path):
[*] xml = self.to_xml(instance_ref, network_info=network_info)
[*] f = open(os.path.join(instance_dir, 'libvirt.xml'), 'w+')
[*] f.write(xml)
[*] f.close()
[*] # libvirt.xml should be made by to_xml(), but libvirt
[*] # does not accept to_xml() result, since uuid is not
[*] # included in to_xml() result.
[*] dom = self._lookup_by_name(instance_ref.name)
[*] self._conn.defineXML(dom.XMLDesc(0))
[*]
[*] def get_instance_disk_info(self, ctxt, instance_ref):
[*]#返回 跟前面的pre_block_migration有些区别
[*] # json strings with below format.
[*] # "[{'path':'disk', 'type':'raw', 'local_gb':'10G'},...]"
[*] """Preparation block migration.
[*]
[*] :params ctxt: security context
[*] :params instance_ref:
[*] nova.db.sqlalchemy.models.Instance object
[*] instance object that is migrated.
[*] :return:
[*] json strings with below format.
[*] "[{'path':'disk', 'type':'raw', 'local_gb':'10G'},...]"
[*]
[*] """
[*] disk_info = []
[*]
[*] virt_dom = self._lookup_by_name(instance_ref.name)
[*] xml = virt_dom.XMLDesc(0)
[*] doc = libxml2.parseDoc(xml)
[*] disk_nodes = doc.xpathEval('//devices/disk')
[*] path_nodes = doc.xpathEval('//devices/disk/source')
[*] driver_nodes = doc.xpathEval('//devices/disk/driver')
[*]
[*] for cnt, path_node in enumerate(path_nodes):
[*] disk_type = disk_nodes.get_properties().getContent()
[*] path = path_node.get_properties().getContent()
[*]
[*] if disk_type != 'file':
[*] LOG.debug(_('skipping %(path)s since it looks like volume') %
[*] locals())
[*] continue
[*]
[*] # In case of libvirt.xml, disk type can be obtained
[*] # by the below statement.
[*] # -> disk_type = driver_nodes.get_properties().getContent()
[*] # but this xml is generated by kvm, format is slightly different.
[*] disk_type = \
[*] driver_nodes.get_properties().get_next().getContent()
[*] if disk_type == 'raw':
[*] size = int(os.path.getsize(path))
[*] else:
[*] out, err = utils.execute('qemu-img', 'info', path)
[*] size = .split() for i in out.split('\n')
[*] if i.strip().find('virtual size') >= 0]
[*] size = int(size)
[*]
[*] # block migration needs same/larger size of empty image on the
[*] # destination host. since qemu-img creates bit smaller size image
[*] # depending on original image size, fixed value is necessary.
[*] for unit, divisor in [('G', 1024 ** 3), ('M', 1024 ** 2),
[*] ('K', 1024), ('', 1)]:
[*] if size / divisor == 0:
[*] continue
[*] if size % divisor != 0:
[*] size = size / divisor + 1
[*] else:
[*] size = size / divisor
[*] size = str(size) + unit
[*] break
[*]
[*] disk_info.append({'type': disk_type, 'path': path,
[*] 'local_gb': size})
[*]
[*] return utils.dumps(disk_info)
[*]
[*] def unfilter_instance(self, instance_ref, network_info):
[*]#在防火墙驱动统一方法的see comments？？？
[*] """See comments of same method in firewall_driver."""
[*] self.firewall_driver.unfilter_instance(instance_ref,
[*] network_info=network_info)
[*]
[*] def update_host_status(self):
[*] """See xenapi_conn.py implementation."""
[*] pass
[*]
[*] def get_host_stats(self, refresh=False):
[*] """See xenapi_conn.py implementation."""
[*] pass
[*]
[*] def host_power_action(self, host, action):
[*]#重启或者关闭 或者...
[*] """Reboots, shuts down or powers up the host."""
[*] pass
[*]
[*] def set_host_enabled(self, host, enabled):
[*] """Sets the specified host's ability to accept new instances."""
[*] pass
)
该文件位于nova/virt/libvirt目录下的connection.py！我只是浅浅的分析了一下类中函数的方法 细节并没有多看，肯定有很多地方是错的 或者不好！希望大家能够帮忙指出错误！
接下来 看源代码如下：中文部分是我加的注释 ！或许大家会问 为什么要看这个connection.py呢 因为我发现该文件外部virt目录下有个connection.py 其中引用了 这个文件 所以觉得这个应该很重要 而且发现 好多方法都是重写的底层的driver的方法
学习了，谢谢分享、、、 不错不错，楼主您辛苦了。。。 我妈常说,我们家要是没有电话就不会这么穷。 怀揣两块，胸怀500万！ 男人靠的住，母猪能上树! 学习了，不错，讲的太有道理了
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