# Copyright 2012 NTT Data. All Rights Reserved.
# Copyright 2012 Yahoo! Inc. All Rights Reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

import functools
import os
import tempfile

import mock
from oslo_concurrency import processutils
from oslo_config import cfg
from oslo_utils import fileutils
import six

from nova.compute import arch
from nova import exception
from nova import objects
from nova import test
from nova.tests.unit import fake_instance
from nova import utils
from nova.virt.disk import api as disk
from nova.virt import images
from nova.virt.libvirt import config as vconfig
from nova.virt.libvirt import utils as libvirt_utils

CONF = cfg.CONF


class LibvirtUtilsTestCase(test.NoDBTestCase):

    @mock.patch('nova.utils.execute')
    def test_copy_image_local(self, mock_execute):
        libvirt_utils.copy_image('src', 'dest')
        mock_execute.assert_called_once_with('cp', 'src', 'dest')

    @mock.patch('nova.virt.libvirt.volume.remotefs.SshDriver.copy_file')
    def test_copy_image_remote_ssh(self, mock_rem_fs_remove):
        self.flags(remote_filesystem_transport='ssh', group='libvirt')
        libvirt_utils.copy_image('src', 'dest', host='host')
        mock_rem_fs_remove.assert_called_once_with('src', 'host:dest',
            on_completion=None, on_execute=None, compression=True)

    @mock.patch('nova.virt.libvirt.volume.remotefs.RsyncDriver.copy_file')
    def test_copy_image_remote_rsync(self, mock_rem_fs_remove):
        self.flags(remote_filesystem_transport='rsync', group='libvirt')
        libvirt_utils.copy_image('src', 'dest', host='host')
        mock_rem_fs_remove.assert_called_once_with('src', 'host:dest',
            on_completion=None, on_execute=None, compression=True)

    @mock.patch('os.path.exists', return_value=True)
    def test_disk_type_from_path(self, mock_exists):
        # Seems like lvm detection
        # if its in /dev ??
        for p in ['/dev/b', '/dev/blah/blah']:
            d_type = libvirt_utils.get_disk_type_from_path(p)
            self.assertEqual('lvm', d_type)

        # Try rbd detection
        d_type = libvirt_utils.get_disk_type_from_path('rbd:pool/instance')
        self.assertEqual('rbd', d_type)

        # Try the other types
        path = '/myhome/disk.config'
        d_type = libvirt_utils.get_disk_type_from_path(path)
        self.assertIsNone(d_type)

    @mock.patch('os.path.exists', return_value=True)
    @mock.patch('nova.utils.execute')
    def test_disk_backing(self, mock_execute, mock_exists):
        path = '/myhome/disk.config'
        template_output = """image: %(path)s
file format: raw
virtual size: 2K (2048 bytes)
cluster_size: 65536
disk size: 96K
"""
        output = template_output % ({
            'path': path,
        })
        mock_execute.return_value = (output, '')
        d_backing = libvirt_utils.get_disk_backing_file(path)
        mock_execute.assert_called_once_with('env', 'LC_ALL=C', 'LANG=C',
                                             'qemu-img', 'info', path,
                                             prlimit=images.QEMU_IMG_LIMITS)
        mock_exists.assert_called_once_with(path)
        self.assertIsNone(d_backing)

    def _test_disk_size(self, mock_execute, path, expected_size):
        d_size = libvirt_utils.get_disk_size(path)
        self.assertEqual(expected_size, d_size)
        mock_execute.assert_called_once_with('env', 'LC_ALL=C', 'LANG=C',
                                             'qemu-img', 'info', path,
                                             prlimit=images.QEMU_IMG_LIMITS)

    @mock.patch('os.path.exists', return_value=True)
    def test_disk_size(self, mock_exists):
        path = '/myhome/disk.config'
        template_output = """image: %(path)s
file format: raw
virtual size: %(v_size)s (%(vsize_b)s bytes)
cluster_size: 65536
disk size: 96K
"""
        for i in range(0, 128):
            bytes = i * 65336
            kbytes = bytes / 1024
            mbytes = kbytes / 1024
            output = template_output % ({
                'v_size': "%sM" % (mbytes),
                'vsize_b': i,
                'path': path,
            })
            with mock.patch('nova.utils.execute',
                return_value=(output, '')) as mock_execute:
                self._test_disk_size(mock_execute, path, i)
            output = template_output % ({
                'v_size': "%sK" % (kbytes),
                'vsize_b': i,
                'path': path,
            })
            with mock.patch('nova.utils.execute',
                return_value=(output, '')) as mock_execute:
                self._test_disk_size(mock_execute, path, i)

    @mock.patch('os.path.exists', return_value=True)
    @mock.patch('nova.utils.execute')
    def test_qemu_info_canon(self, mock_execute, mock_exists):
        path = "disk.config"
        example_output = """image: disk.config
file format: raw
virtual size: 64M (67108864 bytes)
cluster_size: 65536
disk size: 96K
blah BLAH: bb
"""
        mock_execute.return_value = (example_output, '')
        image_info = images.qemu_img_info(path)
        mock_execute.assert_called_once_with('env', 'LC_ALL=C', 'LANG=C',
                                             'qemu-img', 'info', path,
                                             prlimit=images.QEMU_IMG_LIMITS)
        mock_exists.assert_called_once_with(path)
        self.assertEqual('disk.config', image_info.image)
        self.assertEqual('raw', image_info.file_format)
        self.assertEqual(67108864, image_info.virtual_size)
        self.assertEqual(98304, image_info.disk_size)
        self.assertEqual(65536, image_info.cluster_size)

    @mock.patch('os.path.exists', return_value=True)
    @mock.patch('nova.utils.execute')
    def test_qemu_info_canon2(self, mock_execute, mock_exists):
        path = "disk.config"
        example_output = """image: disk.config
file format: QCOW2
virtual size: 67108844
cluster_size: 65536
disk size: 963434
backing file: /var/lib/nova/a328c7998805951a_2
"""
        mock_execute.return_value = (example_output, '')
        image_info = images.qemu_img_info(path)
        mock_execute.assert_called_once_with('env', 'LC_ALL=C', 'LANG=C',
                                             'qemu-img', 'info', path,
                                             prlimit=images.QEMU_IMG_LIMITS)
        mock_exists.assert_called_once_with(path)
        self.assertEqual('disk.config', image_info.image)
        self.assertEqual('qcow2', image_info.file_format)
        self.assertEqual(67108844, image_info.virtual_size)
        self.assertEqual(963434, image_info.disk_size)
        self.assertEqual(65536, image_info.cluster_size)
        self.assertEqual('/var/lib/nova/a328c7998805951a_2',
                         image_info.backing_file)

    @mock.patch('os.path.exists', return_value=True)
    @mock.patch('nova.utils.execute')
    def test_qemu_backing_file_actual(self,
                                      mock_execute, mock_exists):
        path = "disk.config"
        example_output = """image: disk.config
file format: raw
virtual size: 64M (67108864 bytes)
cluster_size: 65536
disk size: 96K
Snapshot list:
ID        TAG                 VM SIZE                DATE       VM CLOCK
1     d9a9784a500742a7bb95627bb3aace38      0 2012-08-20 10:52:46 00:00:00.000
backing file: /var/lib/nova/a328c7998805951a_2 (actual path: /b/3a988059e51a_2)
"""
        mock_execute.return_value = (example_output, '')
        image_info = images.qemu_img_info(path)
        mock_execute.assert_called_once_with('env', 'LC_ALL=C', 'LANG=C',
                                             'qemu-img', 'info', path,
                                             prlimit=images.QEMU_IMG_LIMITS)
        mock_exists.assert_called_once_with(path)
        self.assertEqual('disk.config', image_info.image)
        self.assertEqual('raw', image_info.file_format)
        self.assertEqual(67108864, image_info.virtual_size)
        self.assertEqual(98304, image_info.disk_size)
        self.assertEqual(1, len(image_info.snapshots))
        self.assertEqual('/b/3a988059e51a_2',
                         image_info.backing_file)

    @mock.patch('os.path.exists', return_value=True)
    @mock.patch('nova.utils.execute')
    def test_qemu_info_convert(self, mock_execute, mock_exists):
        path = "disk.config"
        example_output = """image: disk.config
file format: raw
virtual size: 64M
disk size: 96K
Snapshot list:
ID        TAG                 VM SIZE                DATE       VM CLOCK
1        d9a9784a500742a7bb95627bb3aace38    0 2012-08-20 10:52:46 00:00:00.000
3        d9a9784a500742a7bb95627bb3aace38    0 2012-08-20 10:52:46 00:00:00.000
4        d9a9784a500742a7bb95627bb3aace38    0 2012-08-20 10:52:46 00:00:00.000
junk stuff: bbb
"""
        mock_execute.return_value = (example_output, '')
        image_info = images.qemu_img_info(path)
        mock_execute.assert_called_once_with('env', 'LC_ALL=C', 'LANG=C',
                                             'qemu-img', 'info', path,
                                             prlimit=images.QEMU_IMG_LIMITS)
        mock_exists.assert_called_once_with(path)
        self.assertEqual('disk.config', image_info.image)
        self.assertEqual('raw', image_info.file_format)
        self.assertEqual(67108864, image_info.virtual_size)
        self.assertEqual(98304, image_info.disk_size)

    @mock.patch('os.path.exists', return_value=True)
    @mock.patch('nova.utils.execute')
    def test_qemu_info_snaps(self, mock_execute, mock_exists):
        path = "disk.config"
        example_output = """image: disk.config
file format: raw
virtual size: 64M (67108864 bytes)
disk size: 96K
Snapshot list:
ID        TAG                 VM SIZE                DATE       VM CLOCK
1        d9a9784a500742a7bb95627bb3aace38    0 2012-08-20 10:52:46 00:00:00.000
3        d9a9784a500742a7bb95627bb3aace38    0 2012-08-20 10:52:46 00:00:00.000
4        d9a9784a500742a7bb95627bb3aace38    0 2012-08-20 10:52:46 00:00:00.000
"""
        mock_execute.return_value = (example_output, '')
        image_info = images.qemu_img_info(path)
        mock_execute.assert_called_once_with('env', 'LC_ALL=C', 'LANG=C',
                                             'qemu-img', 'info', path,
                                             prlimit=images.QEMU_IMG_LIMITS)
        mock_exists.assert_called_once_with(path)
        self.assertEqual('disk.config', image_info.image)
        self.assertEqual('raw', image_info.file_format)
        self.assertEqual(67108864, image_info.virtual_size)
        self.assertEqual(98304, image_info.disk_size)
        self.assertEqual(3, len(image_info.snapshots))

    def test_valid_hostname_normal(self):
        self.assertTrue(libvirt_utils.is_valid_hostname("hello.world.com"))

    def test_valid_hostname_ipv4addr(self):
        self.assertTrue(libvirt_utils.is_valid_hostname("10.0.2.1"))

    def test_valid_hostname_ipv6addr(self):
        self.assertTrue(libvirt_utils.is_valid_hostname("240:2ac3::2"))

    def test_valid_hostname_bad(self):
        self.assertFalse(libvirt_utils.is_valid_hostname("foo/?com=/bin/sh"))

    @mock.patch('nova.utils.execute')
    def test_create_image(self, mock_execute):
        libvirt_utils.create_image('raw', '/some/path', '10G')
        libvirt_utils.create_image('qcow2', '/some/stuff', '1234567891234')
        expected_args = [(('qemu-img', 'create', '-f', 'raw',
                           '/some/path', '10G'),),
                         (('qemu-img', 'create', '-f', 'qcow2',
                           '/some/stuff', '1234567891234'),)]
        self.assertEqual(expected_args, mock_execute.call_args_list)

    @mock.patch('os.path.exists', return_value=True)
    @mock.patch('nova.utils.execute')
    def test_create_cow_image(self, mock_execute, mock_exists):
        mock_execute.return_value = ('stdout', None)
        libvirt_utils.create_cow_image('/some/path', '/the/new/cow')
        expected_args = [(('env', 'LC_ALL=C', 'LANG=C',
                           'qemu-img', 'info', '/some/path'),
                           {'prlimit': images.QEMU_IMG_LIMITS}),
                         (('qemu-img', 'create', '-f', 'qcow2',
                           '-o', 'backing_file=/some/path',
                           '/the/new/cow'),)]
        self.assertEqual(expected_args, mock_execute.call_args_list)

    def test_pick_disk_driver_name(self):
        type_map = {'kvm': ([True, 'qemu'], [False, 'qemu'], [None, 'qemu']),
                    'qemu': ([True, 'qemu'], [False, 'qemu'], [None, 'qemu']),
                    'uml': ([True, None], [False, None], [None, None]),
                    'lxc': ([True, None], [False, None], [None, None])}
        # NOTE(aloga): Xen is tested in test_pick_disk_driver_name_xen

        version = 1005001
        for (virt_type, checks) in six.iteritems(type_map):
            self.flags(virt_type=virt_type, group='libvirt')
            for (is_block_dev, expected_result) in checks:
                result = libvirt_utils.pick_disk_driver_name(version,
                                                             is_block_dev)
                self.assertEqual(result, expected_result)

    @mock.patch('nova.utils.execute')
    def test_pick_disk_driver_name_xen(self, mock_execute):

        def side_effect(*args, **kwargs):
            if args == ('tap-ctl', 'check'):
                if mock_execute.blktap is True:
                    return ('ok\n', '')
                elif mock_execute.blktap is False:
                    return ('some error\n', '')
                else:
                    raise OSError(2, "No such file or directory")
            elif args == ('xend', 'status'):
                if mock_execute.xend is True:
                    return ('', '')
                elif mock_execute.xend is False:
                    raise processutils.ProcessExecutionError("error")
                else:
                    raise OSError(2, "No such file or directory")
            raise Exception('Unexpected call')
        mock_execute.side_effect = side_effect

        self.flags(virt_type="xen", group='libvirt')
        versions = [4000000, 4001000, 4002000, 4003000, 4005000]
        for version in versions:
            # block dev
            result = libvirt_utils.pick_disk_driver_name(version, True)
            self.assertEqual(result, "phy")
            self.assertFalse(mock_execute.called)
            mock_execute.reset_mock()
            # file dev
            for blktap in True, False, None:
                mock_execute.blktap = blktap
                for xend in True, False, None:
                    mock_execute.xend = xend
                    result = libvirt_utils.pick_disk_driver_name(version,
                                                                 False)
                    # qemu backend supported only by libxl which is
                    # production since xen 4.2. libvirt use libxl if
                    # xend service not started.
                    if version >= 4002000 and xend is not True:
                        self.assertEqual(result, 'qemu')
                    elif blktap:
                        if version == 4000000:
                            self.assertEqual(result, 'tap')
                        else:
                            self.assertEqual(result, 'tap2')
                    else:
                        self.assertEqual(result, 'file')
                    # default is_block_dev False
                    self.assertEqual(result,
                        libvirt_utils.pick_disk_driver_name(version))
                    mock_execute.reset_mock()

    @mock.patch('os.path.exists', return_value=True)
    @mock.patch('nova.utils.execute')
    def test_get_disk_size(self, mock_execute, mock_exists):
        path = '/some/path'
        example_output = """image: 00000001
file format: raw
virtual size: 4.4M (4592640 bytes)
disk size: 4.4M
"""
        mock_execute.return_value = (example_output, '')
        self.assertEqual(4592640, disk.get_disk_size('/some/path'))
        mock_execute.assert_called_once_with('env', 'LC_ALL=C', 'LANG=C',
                                             'qemu-img', 'info', path,
                                             prlimit=images.QEMU_IMG_LIMITS)
        mock_exists.assert_called_once_with(path)

    def test_copy_image(self):
        dst_fd, dst_path = tempfile.mkstemp()
        try:
            os.close(dst_fd)

            src_fd, src_path = tempfile.mkstemp()
            try:
                with os.fdopen(src_fd, 'w') as fp:
                    fp.write('canary')

                libvirt_utils.copy_image(src_path, dst_path)
                with open(dst_path, 'r') as fp:
                    self.assertEqual(fp.read(), 'canary')
            finally:
                os.unlink(src_path)
        finally:
            os.unlink(dst_path)

    def test_write_to_file(self):
        dst_fd, dst_path = tempfile.mkstemp()
        try:
            os.close(dst_fd)

            libvirt_utils.write_to_file(dst_path, 'hello')
            with open(dst_path, 'r') as fp:
                self.assertEqual(fp.read(), 'hello')
        finally:
            os.unlink(dst_path)

    def test_write_to_file_with_umask(self):
        dst_fd, dst_path = tempfile.mkstemp()
        try:
            os.close(dst_fd)
            os.unlink(dst_path)

            libvirt_utils.write_to_file(dst_path, 'hello', umask=0o277)
            with open(dst_path, 'r') as fp:
                self.assertEqual(fp.read(), 'hello')
            mode = os.stat(dst_path).st_mode
            self.assertEqual(mode & 0o277, 0)
        finally:
            os.unlink(dst_path)

    @mock.patch.object(utils, 'execute')
    def test_chown(self, mock_execute):
        libvirt_utils.chown('/some/path', 'soren')
        mock_execute.assert_called_once_with('chown', 'soren', '/some/path',
                                             run_as_root=True)

    @mock.patch.object(utils, 'execute')
    def test_chown_for_id_maps(self, mock_execute):
        id_maps = [vconfig.LibvirtConfigGuestUIDMap(),
                   vconfig.LibvirtConfigGuestUIDMap(),
                   vconfig.LibvirtConfigGuestGIDMap(),
                   vconfig.LibvirtConfigGuestGIDMap()]
        id_maps[0].target = 10000
        id_maps[0].count = 2000
        id_maps[1].start = 2000
        id_maps[1].target = 40000
        id_maps[1].count = 2000
        id_maps[2].target = 10000
        id_maps[2].count = 2000
        id_maps[3].start = 2000
        id_maps[3].target = 40000
        id_maps[3].count = 2000
        libvirt_utils.chown_for_id_maps('/some/path', id_maps)
        execute_args = ('nova-idmapshift', '-i',
                        '-u', '0:10000:2000,2000:40000:2000',
                        '-g', '0:10000:2000,2000:40000:2000',
                        '/some/path')
        mock_execute.assert_called_once_with(*execute_args, run_as_root=True)

    def _do_test_extract_snapshot(self, mock_execute,
                                  dest_format='raw', out_format='raw'):
        libvirt_utils.extract_snapshot('/path/to/disk/image', 'qcow2',
                                       '/extracted/snap', dest_format)
        mock_execute.assert_called_once_with(
            'qemu-img', 'convert', '-f', 'qcow2', '-O', out_format,
            '/path/to/disk/image', '/extracted/snap')

    @mock.patch.object(utils, 'execute')
    def test_extract_snapshot_raw(self, mock_execute):
        self._do_test_extract_snapshot(mock_execute)

    @mock.patch.object(utils, 'execute')
    def test_extract_snapshot_iso(self, mock_execute):
        self._do_test_extract_snapshot(mock_execute, dest_format='iso')

    @mock.patch.object(utils, 'execute')
    def test_extract_snapshot_qcow2(self, mock_execute):
        self._do_test_extract_snapshot(mock_execute,
                                       dest_format='qcow2', out_format='qcow2')

    def test_load_file(self):
        dst_fd, dst_path = tempfile.mkstemp()
        try:
            os.close(dst_fd)

            # We have a test for write_to_file. If that is sound, this suffices
            libvirt_utils.write_to_file(dst_path, 'hello')
            self.assertEqual(libvirt_utils.load_file(dst_path), 'hello')
        finally:
            os.unlink(dst_path)

    def test_file_open(self):
        dst_fd, dst_path = tempfile.mkstemp()
        try:
            os.close(dst_fd)

            # We have a test for write_to_file. If that is sound, this suffices
            libvirt_utils.write_to_file(dst_path, 'hello')
            with libvirt_utils.file_open(dst_path, 'r') as fp:
                self.assertEqual(fp.read(), 'hello')
        finally:
            os.unlink(dst_path)

    def test_get_fs_info(self):

        class FakeStatResult(object):

            def __init__(self):
                self.f_bsize = 4096
                self.f_frsize = 4096
                self.f_blocks = 2000
                self.f_bfree = 1000
                self.f_bavail = 900
                self.f_files = 2000
                self.f_ffree = 1000
                self.f_favail = 900
                self.f_flag = 4096
                self.f_namemax = 255

        self.path = None

        def fake_statvfs(path):
            self.path = path
            return FakeStatResult()

        self.stubs.Set(os, 'statvfs', fake_statvfs)

        fs_info = libvirt_utils.get_fs_info('/some/file/path')
        self.assertEqual('/some/file/path', self.path)
        self.assertEqual(8192000, fs_info['total'])
        self.assertEqual(3686400, fs_info['free'])
        self.assertEqual(4096000, fs_info['used'])

    @mock.patch('nova.virt.images.fetch_to_raw')
    def test_fetch_image(self, mock_images):
        context = 'opaque context'
        target = '/tmp/targetfile'
        image_id = '4'
        user_id = 'fake'
        project_id = 'fake'
        libvirt_utils.fetch_image(context, target, image_id,
                                  user_id, project_id)
        mock_images.assert_called_once_with(
            context, image_id, target, user_id, project_id,
            max_size=0)

    def test_fetch_raw_image(self):

        def fake_execute(*cmd, **kwargs):
            self.executes.append(cmd)
            return None, None

        def fake_rename(old, new):
            self.executes.append(('mv', old, new))

        def fake_unlink(path):
            self.executes.append(('rm', path))

        def fake_rm_on_error(path, remove=None):
            self.executes.append(('rm', '-f', path))

        def fake_qemu_img_info(path):
            class FakeImgInfo(object):
                pass

            file_format = path.split('.')[-1]
            if file_format == 'part':
                file_format = path.split('.')[-2]
            elif file_format == 'converted':
                file_format = 'raw'

            if 'backing' in path:
                backing_file = 'backing'
            else:
                backing_file = None

            if 'big' in path:
                virtual_size = 2
            else:
                virtual_size = 1

            FakeImgInfo.file_format = file_format
            FakeImgInfo.backing_file = backing_file
            FakeImgInfo.virtual_size = virtual_size

            return FakeImgInfo()

        self.stubs.Set(utils, 'execute', fake_execute)
        self.stubs.Set(os, 'rename', fake_rename)
        self.stubs.Set(os, 'unlink', fake_unlink)
        self.stubs.Set(images, 'fetch', lambda *_, **__: None)
        self.stubs.Set(images, 'qemu_img_info', fake_qemu_img_info)
        self.stubs.Set(fileutils, 'delete_if_exists', fake_rm_on_error)

        # Since the remove param of fileutils.remove_path_on_error()
        # is initialized at load time, we must provide a wrapper
        # that explicitly resets it to our fake delete_if_exists()
        old_rm_path_on_error = fileutils.remove_path_on_error
        f = functools.partial(old_rm_path_on_error, remove=fake_rm_on_error)
        self.stubs.Set(fileutils, 'remove_path_on_error', f)

        context = 'opaque context'
        image_id = '4'
        user_id = 'fake'
        project_id = 'fake'

        target = 't.qcow2'
        self.executes = []
        expected_commands = [('qemu-img', 'convert', '-O', 'raw',
                              't.qcow2.part', 't.qcow2.converted',
                              '-f', 'qcow2'),
                             ('rm', 't.qcow2.part'),
                             ('mv', 't.qcow2.converted', 't.qcow2')]
        images.fetch_to_raw(context, image_id, target, user_id, project_id,
                            max_size=1)
        self.assertEqual(self.executes, expected_commands)

        target = 't.raw'
        self.executes = []
        expected_commands = [('mv', 't.raw.part', 't.raw')]
        images.fetch_to_raw(context, image_id, target, user_id, project_id)
        self.assertEqual(self.executes, expected_commands)

        target = 'backing.qcow2'
        self.executes = []
        expected_commands = [('rm', '-f', 'backing.qcow2.part')]
        self.assertRaises(exception.ImageUnacceptable,
                          images.fetch_to_raw,
                          context, image_id, target, user_id, project_id)
        self.assertEqual(self.executes, expected_commands)

        target = 'big.qcow2'
        self.executes = []
        expected_commands = [('rm', '-f', 'big.qcow2.part')]
        self.assertRaises(exception.FlavorDiskSmallerThanImage,
                          images.fetch_to_raw,
                          context, image_id, target, user_id, project_id,
                          max_size=1)
        self.assertEqual(self.executes, expected_commands)

        del self.executes

    def test_get_disk_backing_file(self):
        with_actual_path = False

        def fake_execute(*args, **kwargs):
            if with_actual_path:
                return ("some: output\n"
                        "backing file: /foo/bar/baz (actual path: /a/b/c)\n"
                        "...: ...\n"), ''
            else:
                return ("some: output\n"
                        "backing file: /foo/bar/baz\n"
                        "...: ...\n"), ''

        def return_true(*args, **kwargs):
            return True

        self.stubs.Set(utils, 'execute', fake_execute)
        self.stubs.Set(os.path, 'exists', return_true)

        out = libvirt_utils.get_disk_backing_file('')
        self.assertEqual(out, 'baz')
        with_actual_path = True
        out = libvirt_utils.get_disk_backing_file('')
        self.assertEqual(out, 'c')

    def test_get_instance_path_at_destination(self):
        instance = fake_instance.fake_instance_obj(None, name='fake_inst',
                                                   uuid='fake_uuid')

        migrate_data = None
        inst_path_at_dest = libvirt_utils.get_instance_path_at_destination(
            instance, migrate_data)
        expected_path = os.path.join(CONF.instances_path, instance['uuid'])
        self.assertEqual(expected_path, inst_path_at_dest)

        migrate_data = {}
        inst_path_at_dest = libvirt_utils.get_instance_path_at_destination(
            instance, migrate_data)
        expected_path = os.path.join(CONF.instances_path, instance['uuid'])
        self.assertEqual(expected_path, inst_path_at_dest)

        migrate_data = dict(instance_relative_path='fake_relative_path')
        inst_path_at_dest = libvirt_utils.get_instance_path_at_destination(
            instance, migrate_data)
        expected_path = os.path.join(CONF.instances_path, 'fake_relative_path')
        self.assertEqual(expected_path, inst_path_at_dest)

    def test_get_arch(self):
        image_meta = objects.ImageMeta.from_dict(
            {'properties': {'architecture': "X86_64"}})
        image_arch = libvirt_utils.get_arch(image_meta)
        self.assertEqual(arch.X86_64, image_arch)
