openstack/nova
Code Issues Proposed changes

Teardown container rootfs in host namespace for lxc

Browse Source 
Unlike other hypervisor to directly using image for VM, rootfs need to
be mounted in setup_container() for lxc before launching the domain.

However, this leads to several problems:

* previously spawned container polluted later spawned container, which
  in turn causing lvm device refused to be removed, as bug descirbes
* container rootfs not mounted after nova stop/start sequence

This commit addresses above two issues.

Fixes bug 1091639

Change-Id: I718baa6e46cf07a5458a5b80d42139dd353ae51c
This commit is contained in:
unicell 2012-12-24 18:08:56 +08:00
parent a52af4aee1
commit 5f697f64e5
4 changed files with 36 additions and 30 deletions
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4
nova/tests/test_libvirt.py
View File

@ -4229,7 +4229,7 @@ class LibvirtDriverTestCase(test.TestCase):
block_device_info=None):
pass
def fake_create_domain(xml):
def fake_create_domain(xml, inst_name=''):
return None
def fake_enable_hairpin(instance):
@ -4275,7 +4275,7 @@ class LibvirtDriverTestCase(test.TestCase):
def fake_plug_vifs(instance, network_info):
pass
def fake_create_domain(xml):
def fake_create_domain(xml, inst_name=''):
return None
def fake_enable_hairpin(instance):

10
nova/tests/test_virt.py
View File

@ -95,7 +95,7 @@ class TestVirtDisk(test.TestCase):
self.stubs.Set(utils, 'execute', fake_execute)
def test_lxc_destroy_container(self):
def test_lxc_teardown_container(self):
def proc_mounts(self, mount_point):
mount_points = {
@ -110,26 +110,26 @@ class TestVirtDisk(test.TestCase):
self.stubs.Set(disk_api._DiskImage, '_device_for_path', proc_mounts)
expected_commands = []
disk_api.destroy_container('/mnt/loop/nopart')
disk_api.teardown_container('/mnt/loop/nopart')
expected_commands += [
('umount', '/dev/loop0'),
('losetup', '--detach', '/dev/loop0'),
]
disk_api.destroy_container('/mnt/loop/part')
disk_api.teardown_container('/mnt/loop/part')
expected_commands += [
('umount', '/dev/mapper/loop0p1'),
('kpartx', '-d', '/dev/loop0'),
('losetup', '--detach', '/dev/loop0'),
]
disk_api.destroy_container('/mnt/nbd/nopart')
disk_api.teardown_container('/mnt/nbd/nopart')
expected_commands += [
('umount', '/dev/nbd15'),
('qemu-nbd', '-d', '/dev/nbd15'),
]
disk_api.destroy_container('/mnt/nbd/part')
disk_api.teardown_container('/mnt/nbd/part')
expected_commands += [
('umount', '/dev/mapper/nbd15p1'),
('kpartx', '-d', '/dev/nbd15'),

6
nova/virt/disk/api.py
View File

@ -294,11 +294,11 @@ def setup_container(image, container_dir, use_cow=False):
raise exception.NovaException(img.errors)
def destroy_container(container_dir):
"""Destroy the container once it terminates.
def teardown_container(container_dir):
"""Teardown the container rootfs mounting once it is spawned.
It will umount the container that is mounted,
and delete any linked devices.
and delete any linked devices.
"""
try:
img = _DiskImage(image=None, mount_dir=container_dir)

46
nova/virt/libvirt/driver.py
View File

@ -577,11 +577,6 @@ class LibvirtDriver(driver.ComputeDriver):
target = os.path.join(CONF.instances_path, instance['name'])
LOG.info(_('Deleting instance files %(target)s') % locals(),
instance=instance)
if CONF.libvirt_type == 'lxc':
container_dir = os.path.join(CONF.instances_path,
instance['name'],
'rootfs')
disk.destroy_container(container_dir=container_dir)
if os.path.exists(target):
# If we fail to get rid of the directory
# tree, this shouldn't block deletion of
@ -949,7 +944,7 @@ class LibvirtDriver(driver.ComputeDriver):
power_state.CRASHED]:
LOG.info(_("Instance shutdown successfully."),
instance=instance)
self._create_domain(domain=dom)
self._create_domain(domain=dom, inst_name=instance['name'])
timer = utils.LoopingCall(self._wait_for_running, instance)
timer.start(interval=0.5).wait()
return True
@ -1011,7 +1006,7 @@ class LibvirtDriver(driver.ComputeDriver):
def power_on(self, instance):
"""Power on the specified instance"""
dom = self._lookup_by_name(instance['name'])
self._create_domain(domain=dom)
self._create_domain(domain=dom, inst_name=instance['name'])
timer = utils.LoopingCall(self._wait_for_running, instance)
timer.start(interval=0.5).wait()
@ -1317,12 +1312,6 @@ class LibvirtDriver(driver.ComputeDriver):
LOG.info(_('Creating image'), instance=instance)
libvirt_utils.write_to_file(basepath('libvirt.xml'), libvirt_xml)
if CONF.libvirt_type == 'lxc':
container_dir = os.path.join(CONF.instances_path,
instance['name'],
'rootfs')
fileutils.ensure_tree(container_dir)
# NOTE(dprince): for rescue console.log may already exist... chown it.
self._chown_console_log_for_instance(instance['name'])
@ -1484,11 +1473,6 @@ class LibvirtDriver(driver.ComputeDriver):
'%(img_id)s (%(e)s)') % locals(),
instance=instance)
if CONF.libvirt_type == 'lxc':
disk.setup_container(image('disk').path,
container_dir=container_dir,
use_cow=CONF.use_cow_images)
if CONF.libvirt_type == 'uml':
libvirt_utils.chown(image('disk').path, 'root')
@ -1947,16 +1931,37 @@ class LibvirtDriver(driver.ComputeDriver):
'num_cpu': num_cpu,
'cpu_time': cpu_time}
def _create_domain(self, xml=None, domain=None, launch_flags=0):
def _create_domain(self, xml=None, domain=None,
inst_name='', launch_flags=0):
"""Create a domain.
Either domain or xml must be passed in. If both are passed, then
the domain definition is overwritten from the xml.
"""
if CONF.libvirt_type == 'lxc':
container_dir = os.path.join(CONF.instances_path,
inst_name,
'rootfs')
fileutils.ensure_tree(container_dir)
image = self.image_backend.image(inst_name, 'disk')
disk.setup_container(image.path,
container_dir=container_dir,
use_cow=CONF.use_cow_images)
if xml:
domain = self._conn.defineXML(xml)
domain.createWithFlags(launch_flags)
self._enable_hairpin(domain.XMLDesc(0))
# NOTE(uni): Now the container is running with its own private mount
# namespace and so there is no need to keep the container rootfs
# mounted in the host namespace
if CONF.libvirt_type == 'lxc':
container_dir = os.path.join(CONF.instances_path,
inst_name,
'rootfs')
disk.teardown_container(container_dir=container_dir)
return domain
def _create_domain_and_network(self, xml, instance, network_info,
@ -1976,7 +1981,8 @@ class LibvirtDriver(driver.ComputeDriver):
self.plug_vifs(instance, network_info)
self.firewall_driver.setup_basic_filtering(instance, network_info)
self.firewall_driver.prepare_instance_filter(instance, network_info)
domain = self._create_domain(xml)
domain = self._create_domain(xml, inst_name=instance['name'])
self.firewall_driver.apply_instance_filter(instance, network_info)
return domain