From 6489f2d2b44827d133dad9a3bb52436ee304a934 Mon Sep 17 00:00:00 2001 From: melanie witt Date: Fri, 18 Jan 2019 16:30:40 +0000 Subject: [PATCH] Raise 403 instead of 500 error from attach volume API 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 --- nova/api/openstack/compute/volumes.py | 4 +++- nova/exception.py | 6 ++++++ nova/tests/functional/test_servers.py | 25 +++++++++++++++++++++++++ nova/virt/driver.py | 18 ++++++++++++++++-- nova/virt/libvirt/blockinfo.py | 3 +-- 5 files changed, 51 insertions(+), 5 deletions(-) diff --git a/nova/api/openstack/compute/volumes.py b/nova/api/openstack/compute/volumes.py index a97ae4e3718c..3947526ad70a 100644 --- a/nova/api/openstack/compute/volumes.py +++ b/nova/api/openstack/compute/volumes.py @@ -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 = {} diff --git a/nova/exception.py b/nova/exception.py index a8fcd354ea45..86307456fccd 100644 --- a/nova/exception.py +++ b/nova/exception.py @@ -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") diff --git a/nova/tests/functional/test_servers.py b/nova/tests/functional/test_servers.py index d1af06c171c1..7d8bf5e06aa0 100644 --- a/nova/tests/functional/test_servers.py +++ b/nova/tests/functional/test_servers.py @@ -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' diff --git a/nova/virt/driver.py b/nova/virt/driver.py index 8625bd7abcc6..f63652cb7515 100644 --- a/nova/virt/driver.py +++ b/nova/virt/driver.py @@ -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() diff --git a/nova/virt/libvirt/blockinfo.py b/nova/virt/libvirt/blockinfo.py index 429dc87f85b5..82ca0037243d 100644 --- a/nova/virt/libvirt/blockinfo.py +++ b/nova/virt/libvirt/blockinfo.py @@ -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):