openstack/nova
Code Issues Proposed changes

Raise 403 instead of 500 error from attach volume API

Browse Source 
Currently, the libvirt driver has a limit on the maximum number of
disk devices allowed to attach to a single instance of 26. If a user
attempts to attach a volume which would make the total number of
attached disk devices > 26 for the instance, the user receives a
500 error from the API.

This adds a new exception type TooManyDiskDevices and raises it for the
"No free disk devices names" condition, instead of InternalError, and
handles it in the attach volume API. We raise TooManyDiskDevices
directly from the libvirt driver because InternalError is ambiguous and
can be raised for different error reasons within the same method call.

Closes-Bug: #1770527

Change-Id: I1b08ed6826d7eb41ecdfc7102e5e8fcf3d1eb2e1
This commit is contained in:
melanie witt 2019-01-18 16:30:40 +00:00
parent 56811efa35
commit 6489f2d2b4
5 changed files with 51 additions and 5 deletions
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4
nova/api/openstack/compute/volumes.py
View File

@ -310,7 +310,7 @@ class VolumeAttachmentController(wsgi.Controller):
assigned_mountpoint)}
# TODO(mriedem): This API should return a 202 instead of a 200 response.
@wsgi.expected_errors((400, 404, 409))
@wsgi.expected_errors((400, 403, 404, 409))
@validation.schema(volumes_schema.create_volume_attachment, '2.0', '2.48')
@validation.schema(volumes_schema.create_volume_attachment_v249, '2.49')
def create(self, req, server_id, body):
@ -352,6 +352,8 @@ class VolumeAttachmentController(wsgi.Controller):
exception.MultiattachNotSupportedOldMicroversion,
exception.MultiattachToShelvedNotSupported) as e:
raise exc.HTTPBadRequest(explanation=e.format_message())
except exception.TooManyDiskDevices as e:
raise exc.HTTPForbidden(explanation=e.format_message())
# The attach is async
attachment = {}

6
nova/exception.py
View File

@ -244,6 +244,12 @@ class InvalidBDMVolumeNotBootable(InvalidBDM):
msg_fmt = _("Block Device %(id)s is not bootable.")
class TooManyDiskDevices(InvalidBDM):
msg_fmt = _('The maximum allowed number of disk devices (%(maximum)d) to '
'attach to a single instance has been exceeded.')
code = 403
class InvalidAttribute(Invalid):
msg_fmt = _("Attribute not supported: %(attr)s")

25
nova/tests/functional/test_servers.py
View File

@ -834,6 +834,31 @@ class ServersTest(ServersTestBase):
created_server_id, post)
self.assertEqual(403, ex.response.status_code)
def test_attach_vol_maximum_disk_devices_exceeded(self):
self.useFixture(nova_fixtures.CinderFixtureNewAttachFlow(self))
server = self._build_minimal_create_server_request()
created_server = self.api.post_server({"server": server})
server_id = created_server['id']
self._wait_for_state_change(created_server, 'BUILD')
volume_id = '9a695496-44aa-4404-b2cc-ccab2501f87e'
LOG.info('Attaching volume %s to server %s', volume_id, server_id)
# The fake driver doesn't implement get_device_name_for_instance, so
# we'll just raise the exception directly here, instead of simuluating
# an instance with 26 disk devices already attached.
with mock.patch.object(self.compute.driver,
'get_device_name_for_instance') as mock_get:
mock_get.side_effect = exception.TooManyDiskDevices(maximum=26)
ex = self.assertRaises(
client.OpenStackApiException, self.api.post_server_volume,
server_id, dict(volumeAttachment=dict(volumeId=volume_id)))
expected = ('The maximum allowed number of disk devices (26) to '
'attach to a single instance has been exceeded.')
self.assertEqual(403, ex.response.status_code)
self.assertIn(expected, six.text_type(ex))
class ServersTestV21(ServersTest):
api_major_version = 'v2.1'

18
nova/virt/driver.py
View File

@ -491,7 +491,11 @@ class ComputeDriver(object):
def attach_volume(self, context, connection_info, instance, mountpoint,
disk_bus=None, device_type=None, encryption=None):
"""Attach the disk to the instance at mountpoint using info."""
"""Attach the disk to the instance at mountpoint using info.
:raises TooManyDiskDevices: if the maxmimum allowed devices to attach
to a single instance is exceeded.
"""
raise NotImplementedError()
def detach_volume(self, context, connection_info, instance, mountpoint,
@ -1014,6 +1018,8 @@ class ComputeDriver(object):
:param disk_info: instance disk information
:param migrate_data: a LiveMigrateData object
:returns: migrate_data modified by the driver
:raises TooManyDiskDevices: if the maxmimum allowed devices to attach
to a single instance is exceeded.
"""
raise NotImplementedError()
@ -1706,12 +1712,18 @@ class ComputeDriver(object):
The metadata of the image of the instance.
:param nova.objects.BlockDeviceMapping root_bdm:
The description of the root device.
:raises TooManyDiskDevices: if the maxmimum allowed devices to attach
to a single instance is exceeded.
"""
raise NotImplementedError()
def default_device_names_for_instance(self, instance, root_device_name,
*block_device_lists):
"""Default the missing device names in the block device mapping."""
"""Default the missing device names in the block device mapping.
:raises TooManyDiskDevices: if the maxmimum allowed devices to attach
to a single instance is exceeded.
"""
raise NotImplementedError()
def get_device_name_for_instance(self, instance,
@ -1728,6 +1740,8 @@ class ComputeDriver(object):
implementation if not set.
:returns: The chosen device name.
:raises TooManyDiskDevices: if the maxmimum allowed devices to attach
to a single instance is exceeded.
"""
raise NotImplementedError()

3
nova/virt/libvirt/blockinfo.py
View File

@ -191,8 +191,7 @@ def find_disk_dev_for_disk_bus(mapping, bus,
if disk_dev not in assigned_devices:
return disk_dev
msg = _("No free disk device names for prefix '%s'") % dev_prefix
raise exception.InternalError(msg)
raise exception.TooManyDiskDevices(maximum=max_dev)
def is_disk_bus_valid_for_virt(virt_type, disk_bus):