# Copyright 2012 Michael Still and Canonical 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 contextlib
import hashlib
import os
import time

import mock
from oslo_concurrency import lockutils
from oslo_concurrency import processutils
from oslo_config import cfg
from oslo_log import formatters
from oslo_log import log as logging
from oslo_serialization import jsonutils
from oslo_utils import importutils
from six.moves import cStringIO

from nova import conductor
from nova import context
from nova import objects
from nova import test
from nova.tests.unit import fake_instance
from nova import utils
from nova.virt.libvirt import imagecache
from nova.virt.libvirt import utils as libvirt_utils

CONF = cfg.CONF
CONF.import_opt('compute_manager', 'nova.service')
CONF.import_opt('host', 'nova.netconf')


@contextlib.contextmanager
def intercept_log_messages():
    try:
        mylog = logging.getLogger('nova')
        stream = cStringIO()
        handler = logging.logging.StreamHandler(stream)
        handler.setFormatter(formatters.ContextFormatter())
        mylog.logger.addHandler(handler)
        yield stream
    finally:
        mylog.logger.removeHandler(handler)


class ImageCacheManagerTestCase(test.NoDBTestCase):

    def setUp(self):
        super(ImageCacheManagerTestCase, self).setUp()
        self.stock_instance_names = set(['instance-00000001',
                                         'instance-00000002',
                                         'instance-00000003',
                                         'banana-42-hamster'])

    def test_read_stored_checksum_missing(self):
        self.stub_out('os.path.exists', lambda x: False)
        csum = imagecache.read_stored_checksum('/tmp/foo', timestamped=False)
        self.assertIsNone(csum)

    @mock.patch.object(os.path, 'exists', return_value=True)
    @mock.patch.object(time, 'time', return_value=2000000)
    @mock.patch.object(os.path, 'getmtime', return_value=1000000)
    def test_get_age_of_file(self, mock_getmtime, mock_time, mock_exists):
        image_cache_manager = imagecache.ImageCacheManager()
        exists, age = image_cache_manager._get_age_of_file('/tmp')
        self.assertTrue(exists)
        self.assertEqual(1000000, age)

    @mock.patch.object(os.path, 'exists', return_value=False)
    def test_get_age_of_file_not_exists(self, mock_exists):
        image_cache_manager = imagecache.ImageCacheManager()
        exists, age = image_cache_manager._get_age_of_file('/tmp')
        self.assertFalse(exists)
        self.assertEqual(0, age)

    def test_read_stored_checksum(self):
        with utils.tempdir() as tmpdir:
            self.flags(instances_path=tmpdir)
            self.flags(image_info_filename_pattern=('$instances_path/'
                                                    '%(image)s.info'),
                       group='libvirt')

            csum_input = '{"sha1": "fdghkfhkgjjksfdgjksjkghsdf"}\n'
            fname = os.path.join(tmpdir, 'aaa')
            info_fname = imagecache.get_info_filename(fname)
            f = open(info_fname, 'w')
            f.write(csum_input)
            f.close()

            csum_output = imagecache.read_stored_checksum(fname,
                                                          timestamped=False)
            self.assertEqual(csum_input.rstrip(),
                             '{"sha1": "%s"}' % csum_output)

    def test_read_stored_checksum_legacy_essex(self):
        with utils.tempdir() as tmpdir:
            self.flags(instances_path=tmpdir)
            self.flags(image_info_filename_pattern=('$instances_path/'
                                                    '%(image)s.info'),
                       group='libvirt')

            fname = os.path.join(tmpdir, 'aaa')
            old_fname = fname + '.sha1'
            f = open(old_fname, 'w')
            f.write('fdghkfhkgjjksfdgjksjkghsdf')
            f.close()

            csum_output = imagecache.read_stored_checksum(fname,
                                                          timestamped=False)
            self.assertEqual(csum_output, 'fdghkfhkgjjksfdgjksjkghsdf')
            self.assertFalse(os.path.exists(old_fname))
            info_fname = imagecache.get_info_filename(fname)
            self.assertTrue(os.path.exists(info_fname))

    def test_list_base_images(self):
        listing = ['00000001',
                   'ephemeral_0_20_None',
                   '17d1b00b81642842e514494a78e804e9a511637c_5368709120.info',
                   '00000004',
                   'swap_1000']
        images = ['e97222e91fc4241f49a7f520d1dcf446751129b3_sm',
                  'e09c675c2d1cfac32dae3c2d83689c8c94bc693b_sm',
                  'e97222e91fc4241f49a7f520d1dcf446751129b3',
                  '17d1b00b81642842e514494a78e804e9a511637c',
                  '17d1b00b81642842e514494a78e804e9a511637c_5368709120',
                  '17d1b00b81642842e514494a78e804e9a511637c_10737418240']
        listing.extend(images)

        self.stub_out('os.listdir', lambda x: listing)
        self.stub_out('os.path.isfile', lambda x: True)

        base_dir = '/var/lib/nova/instances/_base'
        self.flags(instances_path='/var/lib/nova/instances')

        image_cache_manager = imagecache.ImageCacheManager()
        image_cache_manager._list_base_images(base_dir)

        sanitized = []
        for ent in image_cache_manager.unexplained_images:
            sanitized.append(ent.replace(base_dir + '/', ''))

        self.assertEqual(sorted(sanitized), sorted(images))

        expected = os.path.join(base_dir,
                                'e97222e91fc4241f49a7f520d1dcf446751129b3')
        self.assertIn(expected, image_cache_manager.unexplained_images)

        expected = os.path.join(base_dir,
                                '17d1b00b81642842e514494a78e804e9a511637c_'
                                '10737418240')
        self.assertIn(expected, image_cache_manager.unexplained_images)

        unexpected = os.path.join(base_dir, '00000004')
        self.assertNotIn(unexpected, image_cache_manager.unexplained_images)

        for ent in image_cache_manager.unexplained_images:
            self.assertTrue(ent.startswith(base_dir))

        self.assertEqual(len(image_cache_manager.originals), 2)

        expected = os.path.join(base_dir,
                                '17d1b00b81642842e514494a78e804e9a511637c')
        self.assertIn(expected, image_cache_manager.originals)

        unexpected = os.path.join(base_dir,
                                  '17d1b00b81642842e514494a78e804e9a511637c_'
                                '10737418240')
        self.assertNotIn(unexpected, image_cache_manager.originals)

        self.assertEqual(1, len(image_cache_manager.back_swap_images))
        self.assertIn('swap_1000', image_cache_manager.back_swap_images)

    def test_list_backing_images_small(self):
        self.stub_out('os.listdir',
                       lambda x: ['_base', 'instance-00000001',
                                  'instance-00000002', 'instance-00000003'])
        self.stub_out('os.path.exists',
                       lambda x: x.find('instance-') != -1)
        self.stubs.Set(libvirt_utils, 'get_disk_backing_file',
                       lambda x: 'e97222e91fc4241f49a7f520d1dcf446751129b3_sm')

        found = os.path.join(CONF.instances_path,
                             CONF.image_cache_subdirectory_name,
                             'e97222e91fc4241f49a7f520d1dcf446751129b3_sm')

        image_cache_manager = imagecache.ImageCacheManager()
        image_cache_manager.unexplained_images = [found]
        image_cache_manager.instance_names = self.stock_instance_names

        inuse_images = image_cache_manager._list_backing_images()

        self.assertEqual(inuse_images, [found])
        self.assertEqual(len(image_cache_manager.unexplained_images), 0)

    def test_list_backing_images_resized(self):
        self.stub_out('os.listdir',
                       lambda x: ['_base', 'instance-00000001',
                                  'instance-00000002', 'instance-00000003'])
        self.stub_out('os.path.exists',
                       lambda x: x.find('instance-') != -1)
        self.stubs.Set(libvirt_utils, 'get_disk_backing_file',
                       lambda x: ('e97222e91fc4241f49a7f520d1dcf446751129b3_'
                                  '10737418240'))

        found = os.path.join(CONF.instances_path,
                             CONF.image_cache_subdirectory_name,
                             'e97222e91fc4241f49a7f520d1dcf446751129b3_'
                             '10737418240')

        image_cache_manager = imagecache.ImageCacheManager()
        image_cache_manager.unexplained_images = [found]
        image_cache_manager.instance_names = self.stock_instance_names

        inuse_images = image_cache_manager._list_backing_images()

        self.assertEqual(inuse_images, [found])
        self.assertEqual(len(image_cache_manager.unexplained_images), 0)

    def test_list_backing_images_instancename(self):
        self.stub_out('os.listdir',
                       lambda x: ['_base', 'banana-42-hamster'])
        self.stub_out('os.path.exists',
                       lambda x: x.find('banana-42-hamster') != -1)
        self.stubs.Set(libvirt_utils, 'get_disk_backing_file',
                       lambda x: 'e97222e91fc4241f49a7f520d1dcf446751129b3_sm')

        found = os.path.join(CONF.instances_path,
                             CONF.image_cache_subdirectory_name,
                             'e97222e91fc4241f49a7f520d1dcf446751129b3_sm')

        image_cache_manager = imagecache.ImageCacheManager()
        image_cache_manager.unexplained_images = [found]
        image_cache_manager.instance_names = self.stock_instance_names

        inuse_images = image_cache_manager._list_backing_images()

        self.assertEqual(inuse_images, [found])
        self.assertEqual(len(image_cache_manager.unexplained_images), 0)

    def test_list_backing_images_disk_notexist(self):
        self.stub_out('os.listdir',
                       lambda x: ['_base', 'banana-42-hamster'])
        self.stub_out('os.path.exists',
                       lambda x: x.find('banana-42-hamster') != -1)

        def fake_get_disk(disk_path):
            raise processutils.ProcessExecutionError()

        self.stubs.Set(libvirt_utils, 'get_disk_backing_file', fake_get_disk)

        image_cache_manager = imagecache.ImageCacheManager()
        image_cache_manager.unexplained_images = []
        image_cache_manager.instance_names = self.stock_instance_names

        self.assertRaises(processutils.ProcessExecutionError,
                          image_cache_manager._list_backing_images)

    def test_find_base_file_nothing(self):
        self.stub_out('os.path.exists', lambda x: False)

        base_dir = '/var/lib/nova/instances/_base'
        fingerprint = '549867354867'
        image_cache_manager = imagecache.ImageCacheManager()
        res = list(image_cache_manager._find_base_file(base_dir, fingerprint))

        self.assertEqual(0, len(res))

    def test_find_base_file_small(self):
        fingerprint = '968dd6cc49e01aaa044ed11c0cce733e0fa44a6a'
        self.stub_out('os.path.exists',
                       lambda x: x.endswith('%s_sm' % fingerprint))

        base_dir = '/var/lib/nova/instances/_base'
        image_cache_manager = imagecache.ImageCacheManager()
        res = list(image_cache_manager._find_base_file(base_dir, fingerprint))

        base_file = os.path.join(base_dir, fingerprint + '_sm')
        self.assertEqual(res, [(base_file, True, False)])

    def test_find_base_file_resized(self):
        fingerprint = '968dd6cc49e01aaa044ed11c0cce733e0fa44a6a'
        listing = ['00000001',
                   'ephemeral_0_20_None',
                   '968dd6cc49e01aaa044ed11c0cce733e0fa44a6a_10737418240',
                   '00000004']

        self.stub_out('os.listdir', lambda x: listing)
        self.stub_out('os.path.exists',
                       lambda x: x.endswith('%s_10737418240' % fingerprint))
        self.stub_out('os.path.isfile', lambda x: True)

        base_dir = '/var/lib/nova/instances/_base'
        image_cache_manager = imagecache.ImageCacheManager()
        image_cache_manager._list_base_images(base_dir)
        res = list(image_cache_manager._find_base_file(base_dir, fingerprint))

        base_file = os.path.join(base_dir, fingerprint + '_10737418240')
        self.assertEqual(res, [(base_file, False, True)])

    def test_find_base_file_all(self):
        fingerprint = '968dd6cc49e01aaa044ed11c0cce733e0fa44a6a'
        listing = ['00000001',
                   'ephemeral_0_20_None',
                   '968dd6cc49e01aaa044ed11c0cce733e0fa44a6a_sm',
                   '968dd6cc49e01aaa044ed11c0cce733e0fa44a6a_10737418240',
                   '00000004']

        self.stub_out('os.listdir', lambda x: listing)
        self.stub_out('os.path.exists', lambda x: True)
        self.stub_out('os.path.isfile', lambda x: True)

        base_dir = '/var/lib/nova/instances/_base'
        image_cache_manager = imagecache.ImageCacheManager()
        image_cache_manager._list_base_images(base_dir)
        res = list(image_cache_manager._find_base_file(base_dir, fingerprint))

        base_file1 = os.path.join(base_dir, fingerprint)
        base_file2 = os.path.join(base_dir, fingerprint + '_sm')
        base_file3 = os.path.join(base_dir, fingerprint + '_10737418240')
        self.assertEqual(res, [(base_file1, False, False),
                               (base_file2, True, False),
                               (base_file3, False, True)])

    @contextlib.contextmanager
    def _make_base_file(self, checksum=True, lock=True):
        """Make a base file for testing."""

        with utils.tempdir() as tmpdir:
            self.flags(instances_path=tmpdir)
            self.flags(image_info_filename_pattern=('$instances_path/'
                                                    '%(image)s.info'),
                       group='libvirt')
            fname = os.path.join(tmpdir, 'aaa')

            base_file = open(fname, 'w')
            base_file.write('data')
            base_file.close()

            if lock:
                lockdir = os.path.join(tmpdir, 'locks')
                lockname = os.path.join(lockdir, 'nova-aaa')
                os.mkdir(lockdir)
                lock_file = open(lockname, 'w')
                lock_file.write('data')
                lock_file.close()

            base_file = open(fname, 'r')

            if checksum:
                imagecache.write_stored_checksum(fname)

            base_file.close()
            yield fname

    def test_remove_base_file(self):
        with self._make_base_file() as fname:
            image_cache_manager = imagecache.ImageCacheManager()
            image_cache_manager._remove_base_file(fname)
            info_fname = imagecache.get_info_filename(fname)

            lock_name = 'nova-' + os.path.split(fname)[-1]
            lock_dir = os.path.join(CONF.instances_path, 'locks')
            lock_file = os.path.join(lock_dir, lock_name)

            # Files are initially too new to delete
            self.assertTrue(os.path.exists(fname))
            self.assertTrue(os.path.exists(info_fname))
            self.assertTrue(os.path.exists(lock_file))

            # Old files get cleaned up though
            os.utime(fname, (-1, time.time() - 3601))
            image_cache_manager._remove_base_file(fname)

            self.assertFalse(os.path.exists(fname))
            self.assertFalse(os.path.exists(info_fname))
            self.assertFalse(os.path.exists(lock_file))

    def test_remove_base_file_original(self):
        with self._make_base_file() as fname:
            image_cache_manager = imagecache.ImageCacheManager()
            image_cache_manager.originals = [fname]
            image_cache_manager._remove_base_file(fname)
            info_fname = imagecache.get_info_filename(fname)

            # Files are initially too new to delete
            self.assertTrue(os.path.exists(fname))
            self.assertTrue(os.path.exists(info_fname))

            # This file should stay longer than a resized image
            os.utime(fname, (-1, time.time() - 3601))
            image_cache_manager._remove_base_file(fname)

            self.assertTrue(os.path.exists(fname))
            self.assertTrue(os.path.exists(info_fname))

            # Originals don't stay forever though
            os.utime(fname, (-1, time.time() - 3600 * 25))
            image_cache_manager._remove_base_file(fname)

            self.assertFalse(os.path.exists(fname))
            self.assertFalse(os.path.exists(info_fname))

    def test_remove_base_file_dne(self):
        # This test is solely to execute the "does not exist" code path. We
        # don't expect the method being tested to do anything in this case.
        with utils.tempdir() as tmpdir:
            self.flags(instances_path=tmpdir)
            self.flags(image_info_filename_pattern=('$instances_path/'
                                                    '%(image)s.info'),
                       group='libvirt')

            fname = os.path.join(tmpdir, 'aaa')
            image_cache_manager = imagecache.ImageCacheManager()
            image_cache_manager._remove_base_file(fname)

    def test_remove_base_file_oserror(self):
        with intercept_log_messages() as stream:
            with utils.tempdir() as tmpdir:
                self.flags(instances_path=tmpdir)
                self.flags(image_info_filename_pattern=('$instances_path/'
                                                        '%(image)s.info'),
                           group='libvirt')

                fname = os.path.join(tmpdir, 'aaa')

                os.mkdir(fname)
                os.utime(fname, (-1, time.time() - 3601))

                # This will raise an OSError because of file permissions
                image_cache_manager = imagecache.ImageCacheManager()
                image_cache_manager._remove_base_file(fname)

                self.assertTrue(os.path.exists(fname))
                self.assertNotEqual(stream.getvalue().find('Failed to remove'),
                                    -1)

    def test_handle_base_image_unused(self):
        img = '123'

        with self._make_base_file() as fname:
            os.utime(fname, (-1, time.time() - 3601))

            image_cache_manager = imagecache.ImageCacheManager()
            image_cache_manager.unexplained_images = [fname]
            image_cache_manager._handle_base_image(img, fname)

            self.assertEqual(image_cache_manager.unexplained_images, [])
            self.assertEqual(image_cache_manager.removable_base_files,
                             [fname])
            self.assertEqual(image_cache_manager.corrupt_base_files, [])

    @mock.patch.object(libvirt_utils, 'update_mtime')
    def test_handle_base_image_used(self, mock_mtime):
        img = '123'

        with self._make_base_file() as fname:
            image_cache_manager = imagecache.ImageCacheManager()
            image_cache_manager.unexplained_images = [fname]
            image_cache_manager.used_images = {'123': (1, 0, ['banana-42'])}
            image_cache_manager._handle_base_image(img, fname)

            mock_mtime.assert_called_once_with(fname)
            self.assertEqual(image_cache_manager.unexplained_images, [])
            self.assertEqual(image_cache_manager.removable_base_files, [])
            self.assertEqual(image_cache_manager.corrupt_base_files, [])

    @mock.patch.object(libvirt_utils, 'update_mtime')
    def test_handle_base_image_used_remotely(self, mock_mtime):
        img = '123'

        with self._make_base_file() as fname:
            image_cache_manager = imagecache.ImageCacheManager()
            image_cache_manager.unexplained_images = [fname]
            image_cache_manager.used_images = {'123': (0, 1, ['banana-42'])}
            image_cache_manager._handle_base_image(img, fname)

            mock_mtime.assert_called_once_with(fname)
            self.assertEqual(image_cache_manager.unexplained_images, [])
            self.assertEqual(image_cache_manager.removable_base_files, [])
            self.assertEqual(image_cache_manager.corrupt_base_files, [])

    def test_handle_base_image_absent(self):
        img = '123'

        with intercept_log_messages() as stream:
            image_cache_manager = imagecache.ImageCacheManager()
            image_cache_manager.used_images = {'123': (1, 0, ['banana-42'])}
            image_cache_manager._handle_base_image(img, None)

            self.assertEqual(image_cache_manager.unexplained_images, [])
            self.assertEqual(image_cache_manager.removable_base_files, [])
            self.assertEqual(image_cache_manager.corrupt_base_files, [])
            self.assertNotEqual(stream.getvalue().find('an absent base file'),
                                -1)

    def test_handle_base_image_used_missing(self):
        img = '123'

        with utils.tempdir() as tmpdir:
            self.flags(instances_path=tmpdir)
            self.flags(image_info_filename_pattern=('$instances_path/'
                                                    '%(image)s.info'),
                       group='libvirt')

            fname = os.path.join(tmpdir, 'aaa')

            image_cache_manager = imagecache.ImageCacheManager()
            image_cache_manager.unexplained_images = [fname]
            image_cache_manager.used_images = {'123': (1, 0, ['banana-42'])}
            image_cache_manager._handle_base_image(img, fname)

            self.assertEqual(image_cache_manager.unexplained_images, [])
            self.assertEqual(image_cache_manager.removable_base_files, [])
            self.assertEqual(image_cache_manager.corrupt_base_files, [])

    @mock.patch.object(libvirt_utils, 'update_mtime')
    def test_handle_base_image_checksum_fails(self, mock_mtime):
        self.flags(checksum_base_images=True, group='libvirt')

        img = '123'

        with self._make_base_file() as fname:
            with open(fname, 'w') as f:
                f.write('banana')

            d = {'sha1': '21323454'}
            with open('%s.info' % fname, 'w') as f:
                f.write(jsonutils.dumps(d))

            image_cache_manager = imagecache.ImageCacheManager()
            image_cache_manager.unexplained_images = [fname]
            image_cache_manager.used_images = {'123': (1, 0, ['banana-42'])}
            image_cache_manager._handle_base_image(img, fname)

            mock_mtime.assert_called_once_with(fname)
            self.assertEqual(image_cache_manager.unexplained_images, [])
            self.assertEqual(image_cache_manager.removable_base_files, [])
            self.assertEqual(image_cache_manager.corrupt_base_files,
                             [fname])

    @mock.patch.object(libvirt_utils, 'update_mtime')
    @mock.patch.object(lockutils, 'external_lock')
    def test_verify_base_images(self, mock_lock, mock_mtime):
        hashed_1 = '356a192b7913b04c54574d18c28d46e6395428ab'
        hashed_21 = '472b07b9fcf2c2451e8781e944bf5f77cd8457c8'
        hashed_22 = '12c6fc06c99a462375eeb3f43dfd832b08ca9e17'
        hashed_42 = '92cfceb39d57d914ed8b14d0e37643de0797ae56'

        self.flags(instances_path='/instance_path',
                   image_cache_subdirectory_name='_base')

        base_file_list = ['00000001',
                          'ephemeral_0_20_None',
                          'e97222e91fc4241f49a7f520d1dcf446751129b3_sm',
                          'e09c675c2d1cfac32dae3c2d83689c8c94bc693b_sm',
                          hashed_42,
                          hashed_1,
                          hashed_21,
                          hashed_22,
                          '%s_5368709120' % hashed_1,
                          '%s_10737418240' % hashed_1,
                          '00000004']

        def fq_path(path):
            return os.path.join('/instance_path/_base/', path)

        # Fake base directory existence
        orig_exists = os.path.exists

        def exists(path):
            # The python coverage tool got angry with my overly broad mocks
            if not path.startswith('/instance_path'):
                return orig_exists(path)

            if path in ['/instance_path',
                        '/instance_path/_base',
                        '/instance_path/instance-1/disk',
                        '/instance_path/instance-2/disk',
                        '/instance_path/instance-3/disk',
                        '/instance_path/_base/%s.info' % hashed_42]:
                return True

            for p in base_file_list:
                if path == fq_path(p):
                    return True
                if path == fq_path(p) + '.info':
                    return False

            if path in ['/instance_path/_base/%s_sm' % i for i in [hashed_1,
                                                                   hashed_21,
                                                                   hashed_22,
                                                                   hashed_42]]:
                return False

            self.fail('Unexpected path existence check: %s' % path)

        self.stub_out('os.path.exists', lambda x: exists(x))

        # Fake up some instances in the instances directory
        orig_listdir = os.listdir

        def listdir(path):
            # The python coverage tool got angry with my overly broad mocks
            if not path.startswith('/instance_path'):
                return orig_listdir(path)

            if path == '/instance_path':
                return ['instance-1', 'instance-2', 'instance-3', '_base']

            if path == '/instance_path/_base':
                return base_file_list

            self.fail('Unexpected directory listed: %s' % path)

        self.stub_out('os.listdir', lambda x: listdir(x))

        # Fake isfile for these faked images in _base
        orig_isfile = os.path.isfile

        def isfile(path):
            # The python coverage tool got angry with my overly broad mocks
            if not path.startswith('/instance_path'):
                return orig_isfile(path)

            for p in base_file_list:
                if path == fq_path(p):
                    return True

            self.fail('Unexpected isfile call: %s' % path)

        self.stub_out('os.path.isfile', lambda x: isfile(x))

        # Fake the database call which lists running instances
        instances = [{'image_ref': '1',
                      'host': CONF.host,
                      'name': 'instance-1',
                      'uuid': '123',
                      'vm_state': '',
                      'task_state': ''},
                     {'image_ref': '1',
                      'kernel_id': '21',
                      'ramdisk_id': '22',
                      'host': CONF.host,
                      'name': 'instance-2',
                      'uuid': '456',
                      'vm_state': '',
                      'task_state': ''}]
        all_instances = [fake_instance.fake_instance_obj(None, **instance)
                         for instance in instances]
        image_cache_manager = imagecache.ImageCacheManager()

        # Fake the utils call which finds the backing image
        def get_disk_backing_file(path):
            if path in ['/instance_path/instance-1/disk',
                        '/instance_path/instance-2/disk']:
                return fq_path('%s_5368709120' % hashed_1)
            self.fail('Unexpected backing file lookup: %s' % path)

        self.stubs.Set(libvirt_utils, 'get_disk_backing_file',
                       lambda x: get_disk_backing_file(x))

        # Fake out verifying checksums, as that is tested elsewhere
        self.stubs.Set(image_cache_manager, '_verify_checksum',
                       lambda x, y: True)

        # Fake getmtime as well
        orig_getmtime = os.path.getmtime

        def getmtime(path):
            if not path.startswith('/instance_path'):
                return orig_getmtime(path)

            return 1000000

        self.stub_out('os.path.getmtime', lambda x: getmtime(x))

        # Make sure we don't accidentally remove a real file
        orig_remove = os.remove

        def remove(path):
            if not path.startswith('/instance_path'):
                return orig_remove(path)

            # Don't try to remove fake files
            return

        self.stub_out('os.remove', lambda x: remove(x))

        self.mox.StubOutWithMock(objects.block_device.BlockDeviceMappingList,
                   'get_by_instance_uuid')

        ctxt = context.get_admin_context()
        objects.block_device.BlockDeviceMappingList.get_by_instance_uuid(
                ctxt, '123').AndReturn(None)
        objects.block_device.BlockDeviceMappingList.get_by_instance_uuid(
                ctxt, '456').AndReturn(None)

        self.mox.ReplayAll()
        # And finally we can make the call we're actually testing...
        # The argument here should be a context, but it is mocked out
        image_cache_manager.update(ctxt, all_instances)

        # Verify
        active = [fq_path(hashed_1), fq_path('%s_5368709120' % hashed_1),
                  fq_path(hashed_21), fq_path(hashed_22)]
        for act in active:
            self.assertIn(act, image_cache_manager.active_base_files)
        self.assertEqual(len(image_cache_manager.active_base_files),
                         len(active))

        for rem in [fq_path('e97222e91fc4241f49a7f520d1dcf446751129b3_sm'),
                    fq_path('e09c675c2d1cfac32dae3c2d83689c8c94bc693b_sm'),
                    fq_path(hashed_42),
                    fq_path('%s_10737418240' % hashed_1)]:
            self.assertIn(rem, image_cache_manager.removable_base_files)

        # Ensure there are no "corrupt" images as well
        self.assertEqual(len(image_cache_manager.corrupt_base_files), 0)

    def test_verify_base_images_no_base(self):
        self.flags(instances_path='/tmp/no/such/dir/name/please')
        image_cache_manager = imagecache.ImageCacheManager()
        image_cache_manager.update(None, [])

    def test_is_valid_info_file(self):
        hashed = 'e97222e91fc4241f49a7f520d1dcf446751129b3'

        self.flags(instances_path='/tmp/no/such/dir/name/please')
        self.flags(image_info_filename_pattern=('$instances_path/_base/'
                                                '%(image)s.info'),
                   group='libvirt')
        base_filename = os.path.join(CONF.instances_path, '_base', hashed)

        is_valid_info_file = imagecache.is_valid_info_file
        self.assertFalse(is_valid_info_file('banana'))
        self.assertFalse(is_valid_info_file(
                os.path.join(CONF.instances_path, '_base', '00000001')))
        self.assertFalse(is_valid_info_file(base_filename))
        self.assertFalse(is_valid_info_file(base_filename + '.sha1'))
        self.assertTrue(is_valid_info_file(base_filename + '.info'))

    def test_configured_checksum_path(self):
        with utils.tempdir() as tmpdir:
            self.flags(instances_path=tmpdir)
            self.flags(image_info_filename_pattern=('$instances_path/'
                                                    '%(image)s.info'),
                       group='libvirt')

            # Ensure there is a base directory
            os.mkdir(os.path.join(tmpdir, '_base'))

            # Fake the database call which lists running instances
            instances = [{'image_ref': '1',
                          'host': CONF.host,
                          'name': 'instance-1',
                          'uuid': '123',
                          'vm_state': '',
                          'task_state': ''},
                         {'image_ref': '1',
                          'host': CONF.host,
                          'name': 'instance-2',
                          'uuid': '456',
                          'vm_state': '',
                          'task_state': ''}]

            all_instances = []
            for instance in instances:
                all_instances.append(fake_instance.fake_instance_obj(
                    None, **instance))

            def touch(filename):
                f = open(filename, 'w')
                f.write('Touched')
                f.close()

            old = time.time() - (25 * 3600)
            hashed = 'e97222e91fc4241f49a7f520d1dcf446751129b3'
            base_filename = os.path.join(tmpdir, hashed)
            touch(base_filename)
            touch(base_filename + '.info')
            os.utime(base_filename + '.info', (old, old))
            touch(base_filename + '.info')
            os.utime(base_filename + '.info', (old, old))

            self.mox.StubOutWithMock(
                objects.block_device.BlockDeviceMappingList,
                'get_by_instance_uuid')

            ctxt = context.get_admin_context()
            objects.block_device.BlockDeviceMappingList.get_by_instance_uuid(
                ctxt, '123').AndReturn(None)
            objects.block_device.BlockDeviceMappingList.get_by_instance_uuid(
                ctxt, '456').AndReturn(None)

            self.mox.ReplayAll()

            image_cache_manager = imagecache.ImageCacheManager()
            image_cache_manager.update(ctxt,
                                       all_instances)

            self.assertTrue(os.path.exists(base_filename))
            self.assertTrue(os.path.exists(base_filename + '.info'))

    def test_run_image_cache_manager_pass(self):
        was = {'called': False}

        def fake_get_all_by_filters(context, *args, **kwargs):
            was['called'] = True
            instances = []
            for x in range(2):
                instances.append(fake_instance.fake_db_instance(
                                                        image_ref='1',
                                                        uuid=x,
                                                        name=x,
                                                        vm_state='',
                                                        task_state=''))
            return instances

        with utils.tempdir() as tmpdir:
            self.flags(instances_path=tmpdir)

            self.stub_out('nova.db.instance_get_all_by_filters',
                          fake_get_all_by_filters)
            compute = importutils.import_object(CONF.compute_manager)
            self.flags(use_local=True, group='conductor')
            compute.conductor_api = conductor.API()
            ctxt = context.get_admin_context()
            compute._run_image_cache_manager_pass(ctxt)
            self.assertTrue(was['called'])

    def test_store_swap_image(self):
        image_cache_manager = imagecache.ImageCacheManager()
        image_cache_manager._store_swap_image('swap_')
        image_cache_manager._store_swap_image('swap_123')
        image_cache_manager._store_swap_image('swap_456')
        image_cache_manager._store_swap_image('swap_abc')
        image_cache_manager._store_swap_image('123_swap')
        image_cache_manager._store_swap_image('swap_129_')

        self.assertEqual(len(image_cache_manager.back_swap_images), 2)
        expect_set = set(['swap_123', 'swap_456'])
        self.assertEqual(image_cache_manager.back_swap_images, expect_set)

    @mock.patch.object(lockutils, 'external_lock')
    @mock.patch.object(libvirt_utils, 'update_mtime')
    @mock.patch('os.path.exists', return_value=True)
    @mock.patch('os.path.getmtime')
    @mock.patch('os.remove')
    def test_age_and_verify_swap_images(self, mock_remove, mock_getmtime,
            mock_exist, mock_mtime, mock_lock):
        image_cache_manager = imagecache.ImageCacheManager()
        expected_remove = set()
        expected_exist = set(['swap_128', 'swap_256'])

        image_cache_manager.back_swap_images.add('swap_128')
        image_cache_manager.back_swap_images.add('swap_256')

        image_cache_manager.used_swap_images.add('swap_128')

        def getmtime(path):
            return time.time() - 1000000

        mock_getmtime.side_effect = getmtime

        def removefile(path):
            if not path.startswith('/tmp_age_test'):
                return os.remove(path)

            fn = os.path.split(path)[-1]
            expected_remove.add(fn)
            expected_exist.remove(fn)

        mock_remove.side_effect = removefile

        image_cache_manager._age_and_verify_swap_images(None, '/tmp_age_test')
        self.assertEqual(1, len(expected_exist))
        self.assertEqual(1, len(expected_remove))
        self.assertIn('swap_128', expected_exist)
        self.assertIn('swap_256', expected_remove)

    @mock.patch.object(utils, 'synchronized')
    @mock.patch.object(imagecache.ImageCacheManager, '_get_age_of_file',
                       return_value=(True, 100))
    def test_lock_acquired_on_removing_old_enough_files(self, mock_get_age,
                                                        mock_synchronized):
        base_file = '/tmp_age_test'
        lock_path = os.path.join(CONF.instances_path, 'locks')
        lock_file = os.path.split(base_file)[-1]
        image_cache_manager = imagecache.ImageCacheManager()
        image_cache_manager._remove_old_enough_file(
            base_file, 60, remove_sig=False, remove_lock=False)
        mock_synchronized.assert_called_once_with(lock_file, external=True,
                                                  lock_path=lock_path)


class VerifyChecksumTestCase(test.NoDBTestCase):

    def setUp(self):
        super(VerifyChecksumTestCase, self).setUp()
        self.img = {'container_format': 'ami', 'id': '42'}
        self.flags(checksum_base_images=True, group='libvirt')

    def _make_checksum(self, tmpdir):
        testdata = ('OpenStack Software delivers a massively scalable cloud '
                    'operating system.')

        fname = os.path.join(tmpdir, 'aaa')
        info_fname = imagecache.get_info_filename(fname)

        with open(fname, 'w') as f:
            f.write(testdata)

        return fname, info_fname, testdata

    def _write_file(self, info_fname, info_attr, testdata):
        f = open(info_fname, 'w')
        if info_attr == "csum valid":
            csum = hashlib.sha1()
            csum.update(testdata)
            f.write('{"sha1": "%s"}\n' % csum.hexdigest())
        elif info_attr == "csum invalid, not json":
            f.write('banana')
        else:
            f.write('{"sha1": "banana"}')
        f.close()

    def _check_body(self, tmpdir, info_attr):
        self.flags(instances_path=tmpdir)
        self.flags(image_info_filename_pattern=('$instances_path/'
                                                '%(image)s.info'),
                   group='libvirt')
        fname, info_fname, testdata = self._make_checksum(tmpdir)
        self._write_file(info_fname, info_attr, testdata)
        image_cache_manager = imagecache.ImageCacheManager()
        return image_cache_manager, fname

    def test_verify_checksum(self):
        with utils.tempdir() as tmpdir:
            image_cache_manager, fname = self._check_body(tmpdir, "csum valid")
            res = image_cache_manager._verify_checksum(self.img, fname)
            self.assertTrue(res)

    def test_verify_checksum_disabled(self):
        self.flags(checksum_base_images=False, group='libvirt')
        with utils.tempdir() as tmpdir:
            image_cache_manager, fname = self._check_body(tmpdir, "csum valid")
            res = image_cache_manager._verify_checksum(self.img, fname)
            self.assertIsNone(res)

    def test_verify_checksum_invalid_json(self):
        with intercept_log_messages() as stream:
            with utils.tempdir() as tmpdir:
                image_cache_manager, fname = (
                    self._check_body(tmpdir, "csum invalid, not json"))
                res = image_cache_manager._verify_checksum(
                    self.img, fname, create_if_missing=False)
                self.assertFalse(res)
                log = stream.getvalue()

                # NOTE(mikal): this is a skip not a fail because the file is
                # present, but is not in valid JSON format and therefore is
                # skipped.
                self.assertNotEqual(log.find('image verification skipped'), -1)

    def test_verify_checksum_invalid_repaired(self):
        with utils.tempdir() as tmpdir:
            image_cache_manager, fname = (
                self._check_body(tmpdir, "csum invalid, not json"))
            res = image_cache_manager._verify_checksum(
                self.img, fname, create_if_missing=True)
            self.assertIsNone(res)

    def test_verify_checksum_invalid(self):
        with intercept_log_messages() as stream:
            with utils.tempdir() as tmpdir:
                image_cache_manager, fname = (
                    self._check_body(tmpdir, "csum invalid, valid json"))
                res = image_cache_manager._verify_checksum(self.img, fname)
                self.assertFalse(res)
                log = stream.getvalue()
                self.assertNotEqual(log.find('image verification failed'), -1)

    def test_verify_checksum_file_missing(self):
        with utils.tempdir() as tmpdir:
            self.flags(instances_path=tmpdir)
            self.flags(image_info_filename_pattern=('$instances_path/'
                                                    '%(image)s.info'),
                       group='libvirt')
            fname, info_fname, testdata = self._make_checksum(tmpdir)

            image_cache_manager = imagecache.ImageCacheManager()
            res = image_cache_manager._verify_checksum('aaa', fname)
            self.assertIsNone(res)

            # Checksum requests for a file with no checksum now have the
            # side effect of creating the checksum
            self.assertTrue(os.path.exists(info_fname))
