openstack
/
nova
Code Issues Proposed changes

libvirt: move checking CONF.my_ip to init_host() 

Migrations use the libvirt driver's get_host_ip_addr() method to
determine the dest_host field of the migration object.
get_host_ip_addr() checks whether CONF.my_ip is actually assigned to
one of the host's interfaces. It does so by calling
get_machine_ips(), which iterates over all of the host's interfaces.
If the host has many interfaces, this can take a long time, and
introduces needless delays in processing the migration.
get_machine_ips() is only used to print a warning, so this patch moves
the get_machine_ips() call to a single method in init_host(). This
way, a warning is still emitted at compute service startup, and
migration progress is not needlessly slowed down.

NOTE(artom) While the following paragraph still applies, the poison
patch will not be backported. Stubbing out use of
netifaces.interfaces() is still a good thing to do, however.

This patch also has a chicken and egg problem with the patch on top of
it, which poisons use of netifaces.interfaces() in tests. While this
patch fixes all the tests that break with that poison, it starts
breaking different tests because of the move of get_machine_ips() into
init_host(). Therefore, while not directly related to the bug, this
patch also preventatively mocks or stubs out any use of
get_machine_ips() that will get poisoned with the subsequent patch.

(cherry picked from commit 30d8159d4e)

(cherry picked from commit 560317c766)

(cherry picked from commit 65d2e455e3)
Conflicts:
  nova/tests/unit/virt/libvirt/fakelibvirt.py
    Due to 23fd6c2287 which mocked out
    get_fs_info() at the same place as this patch mocks out
    get_machine_ips().
nova/virt/libvirt/driver.py
    Due to cbc28f0d15 which added
    _check_file_backed_memory_support() to init_host() at the same
    place this patch added _check_my_ip().

Closes-bug: 1837075
Change-Id: I58a4038b04d5a9c28927d914e71609e4deea3d9f
This commit is contained in:
Artom Lifshitz 2019-07-19 11:35:24 -04:00
parent 95a35cbee4
commit 028a8e949e
4 changed files with 25 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
nova/tests/unit/virt/libvirt/fakelibvirt.py
View File

@ -1535,6 +1535,9 @@ class FakeLibvirtFixture(fixtures.Fixture):
# NOTE(mdbooth): The strange incantation below means 'this module'
self.useFixture(fixtures.MonkeyPatch(i, sys.modules[__name__]))
self.useFixture(
fixtures.MockPatch('nova.compute.utils.get_machine_ips'))
disable_event_thread(self)
if self.stub_os_vif:

14
nova/tests/unit/virt/libvirt/test_driver.py
View File

@ -805,6 +805,8 @@ class LibvirtConnTestCase(test.NoDBTestCase,
self.stubs.Set(imagebackend.Image, 'resolve_driver_format',
imagebackend.Image._get_driver_format)
self.stub_out('nova.compute.utils.get_machine_ips', lambda: [])
self.useFixture(fakelibvirt.FakeLibvirtFixture())
self.test_instance = _create_test_instance()
self.test_image_meta = {
@ -12929,16 +12931,22 @@ class LibvirtConnTestCase(test.NoDBTestCase,
@mock.patch.object(libvirt_driver.LOG, 'warning')
@mock.patch('nova.compute.utils.get_machine_ips')
def test_get_host_ip_addr_failure(self, mock_ips, mock_log):
def test_check_my_ip(self, mock_ips, mock_log):
mock_ips.return_value = ['8.8.8.8', '75.75.75.75']
drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
drvr.get_host_ip_addr()
drvr._check_my_ip()
mock_log.assert_called_once_with(u'my_ip address (%(my_ip)s) was '
u'not found on any of the '
u'interfaces: %(ifaces)s',
{'ifaces': '8.8.8.8, 75.75.75.75',
'my_ip': mock.ANY})
def test_init_host_checks_ip(self):
drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), True)
with mock.patch.object(drvr, '_check_my_ip') as mock_check:
drvr.init_host('fake-host')
mock_check.assert_called_once_with()
def test_conn_event_handler(self):
self.mox.UnsetStubs()
drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), True)
@ -19890,6 +19898,8 @@ class LibvirtDriverTestCase(test.NoDBTestCase):
self.assertEqual(set([uuids.mdev1]),
drvr._get_existing_mdevs_not_assigned())
@mock.patch('nova.compute.utils.get_machine_ips',
new=mock.Mock(return_value=[]))
@mock.patch.object(nova.privsep.libvirt, 'create_mdev')
@mock.patch.object(libvirt_driver.LibvirtDriver,
'_get_mdev_capable_devices')

1
nova/tests/unit/virt/test_virt_drivers.py
View File

@ -889,6 +889,7 @@ class LibvirtConnTestCase(_VirtDriverTestCase, test.TestCase):
# will try to execute some commands which hangs tests so let's just
# stub out the unplug call to os-vif since we don't care about it.
self.stub_out('os_vif.unplug', lambda a, kw: None)
self.stub_out('nova.compute.utils.get_machine_ips', lambda: [])
def _fake_admin_context(self, *args, **kwargs):
return self.ctxt

14
nova/virt/libvirt/driver.py
View File

@ -500,6 +500,8 @@ class LibvirtDriver(driver.ComputeDriver):
self._set_multiattach_support()
self._check_my_ip()
if (CONF.libvirt.virt_type == 'lxc' and
not (CONF.libvirt.uid_maps and CONF.libvirt.gid_maps)):
LOG.warning("Running libvirt-lxc without user namespaces is "
@ -621,6 +623,13 @@ class LibvirtDriver(driver.ComputeDriver):
'versions of QEMU and libvirt. QEMU must be less than '
'2.10 or libvirt must be greater than or equal to 3.10.')
def _check_my_ip(self):
ips = compute_utils.get_machine_ips()
if CONF.my_ip not in ips:
LOG.warning('my_ip address (%(my_ip)s) was not found on '
'any of the interfaces: %(ifaces)s',
{'my_ip': CONF.my_ip, 'ifaces': ", ".join(ips)})
def _prepare_migration_flags(self):
migration_flags = 0
@ -3226,11 +3235,6 @@ class LibvirtDriver(driver.ComputeDriver):
return self._get_console_output_file(instance, console_log)
def get_host_ip_addr(self):
ips = compute_utils.get_machine_ips()
if CONF.my_ip not in ips:
LOG.warning('my_ip address (%(my_ip)s) was not found on '
'any of the interfaces: %(ifaces)s',
{'my_ip': CONF.my_ip, 'ifaces': ", ".join(ips)})
return CONF.my_ip
def get_vnc_console(self, context, instance):