port format inspector tests from glance

This commit is a direct port of the format inspector
unit tests from glance as of commit
0d8e79b713bc31a78f0f4eac14ee594ca8520999

the only changes to the test are as follows

"from glance.common import format_inspector" was updated to
"from nova.image import format_inspector"

"from glance.tests import utils as test_utils"
was replaced with "from nova import test"

"test_utils.BaseTestCase" was replaced with "test.NoDBTestCase"

"glance-unittest-formatinspector-" was replaced with
"nova-unittest-formatinspector-"

This makes the test funtional in nova.

TestFormatInspectors requries qemu-img to be installed on the
host which would be a new depency for executing unit tests.
to avoid that we skip TestFormatInspectors if qemu-img
is not installed.
TestFormatInspectorInfra and TestFormatInspectorsTargeted
do not have a qemu-img dependency so
no changes to the test assertions were required.

Change-Id: Ia34203f246f0bc574e11476287dfb33fda7954fe
(cherry picked from commit 838daa3cad)
(cherry picked from commit 66205be426)
(cherry picked from commit 497abea5a1)
This commit is contained in:
Sean Mooney 2024-07-04 12:38:39 +01:00
parent f732f84768
commit 58cd955c7d

View File

@ -0,0 +1,517 @@
# Copyright 2020 Red Hat, 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 io
import os
import re
import struct
import subprocess
import tempfile
from unittest import mock
from oslo_utils import units
from nova.image import format_inspector
from nova import test
def get_size_from_qemu_img(filename):
output = subprocess.check_output('qemu-img info "%s"' % filename,
shell=True)
for line in output.split(b'\n'):
m = re.search(b'^virtual size: .* .([0-9]+) bytes', line.strip())
if m:
return int(m.group(1))
raise Exception('Could not find virtual size with qemu-img')
class TestFormatInspectors(test.NoDBTestCase):
def setUp(self):
super(TestFormatInspectors, self).setUp()
# these tests depend on qemu-img being installed
# and in the path, if it is not installed, skip
try:
subprocess.check_output('qemu-img --version', shell=True)
except Exception:
self.skipTest('qemu-img not installed')
self._created_files = []
def tearDown(self):
super(TestFormatInspectors, self).tearDown()
for fn in self._created_files:
try:
os.remove(fn)
except Exception:
pass
def _create_img(self, fmt, size, subformat=None, options=None,
backing_file=None):
if fmt == 'vhd':
# QEMU calls the vhd format vpc
fmt = 'vpc'
if options is None:
options = {}
opt = ''
prefix = 'nova-unittest-formatinspector-'
if subformat:
options['subformat'] = subformat
prefix += subformat + '-'
if options:
opt += '-o ' + ','.join('%s=%s' % (k, v)
for k, v in options.items())
if backing_file is not None:
opt += ' -b %s -F raw' % backing_file
fn = tempfile.mktemp(prefix=prefix,
suffix='.%s' % fmt)
self._created_files.append(fn)
subprocess.check_output(
'qemu-img create -f %s %s %s %i' % (fmt, opt, fn, size),
shell=True)
return fn
def _create_allocated_vmdk(self, size_mb, subformat=None):
# We need a "big" VMDK file to exercise some parts of the code of the
# format_inspector. A way to create one is to first create an empty
# file, and then to convert it with the -S 0 option.
if subformat is None:
# Matches qemu-img default, see `qemu-img convert -O vmdk -o help`
subformat = 'monolithicSparse'
prefix = 'nova-unittest-formatinspector-%s-' % subformat
fn = tempfile.mktemp(prefix=prefix, suffix='.vmdk')
self._created_files.append(fn)
raw = tempfile.mktemp(prefix=prefix, suffix='.raw')
self._created_files.append(raw)
# Create a file with pseudo-random data, otherwise it will get
# compressed in the streamOptimized format
subprocess.check_output(
'dd if=/dev/urandom of=%s bs=1M count=%i' % (raw, size_mb),
shell=True)
# Convert it to VMDK
subprocess.check_output(
'qemu-img convert -f raw -O vmdk -o subformat=%s -S 0 %s %s' % (
subformat, raw, fn),
shell=True)
return fn
def _test_format_at_block_size(self, format_name, img, block_size):
fmt = format_inspector.get_inspector(format_name)()
self.assertIsNotNone(fmt,
'Did not get format inspector for %s' % (
format_name))
wrapper = format_inspector.InfoWrapper(open(img, 'rb'), fmt)
while True:
chunk = wrapper.read(block_size)
if not chunk:
break
wrapper.close()
return fmt
def _test_format_at_image_size(self, format_name, image_size,
subformat=None):
img = self._create_img(format_name, image_size, subformat=subformat)
# Some formats have internal alignment restrictions making this not
# always exactly like image_size, so get the real value for comparison
virtual_size = get_size_from_qemu_img(img)
# Read the format in various sizes, some of which will read whole
# sections in a single read, others will be completely unaligned, etc.
for block_size in (64 * units.Ki, 512, 17, 1 * units.Mi):
fmt = self._test_format_at_block_size(format_name, img, block_size)
self.assertTrue(fmt.format_match,
'Failed to match %s at size %i block %i' % (
format_name, image_size, block_size))
self.assertEqual(virtual_size, fmt.virtual_size,
('Failed to calculate size for %s at size %i '
'block %i') % (format_name, image_size,
block_size))
memory = sum(fmt.context_info.values())
self.assertLess(memory, 512 * units.Ki,
'Format used more than 512KiB of memory: %s' % (
fmt.context_info))
def _test_format(self, format_name, subformat=None):
# Try a few different image sizes, including some odd and very small
# sizes
for image_size in (512, 513, 2057, 7):
self._test_format_at_image_size(format_name, image_size * units.Mi,
subformat=subformat)
def test_qcow2(self):
self._test_format('qcow2')
def test_vhd(self):
self._test_format('vhd')
def test_vhdx(self):
self._test_format('vhdx')
def test_vmdk(self):
self._test_format('vmdk')
def test_vmdk_stream_optimized(self):
self._test_format('vmdk', 'streamOptimized')
def test_from_file_reads_minimum(self):
img = self._create_img('qcow2', 10 * units.Mi)
file_size = os.stat(img).st_size
fmt = format_inspector.QcowInspector.from_file(img)
# We know everything we need from the first 512 bytes of a QCOW image,
# so make sure that we did not read the whole thing when we inspect
# a local file.
self.assertLess(fmt.actual_size, file_size)
def test_qed_always_unsafe(self):
img = self._create_img('qed', 10 * units.Mi)
fmt = format_inspector.get_inspector('qed').from_file(img)
self.assertTrue(fmt.format_match)
self.assertFalse(fmt.safety_check())
def _test_vmdk_bad_descriptor_offset(self, subformat=None):
format_name = 'vmdk'
image_size = 10 * units.Mi
descriptorOffsetAddr = 0x1c
BAD_ADDRESS = 0x400
img = self._create_img(format_name, image_size, subformat=subformat)
# Corrupt the header
fd = open(img, 'r+b')
fd.seek(descriptorOffsetAddr)
fd.write(struct.pack('<Q', BAD_ADDRESS // 512))
fd.close()
# Read the format in various sizes, some of which will read whole
# sections in a single read, others will be completely unaligned, etc.
for block_size in (64 * units.Ki, 512, 17, 1 * units.Mi):
fmt = self._test_format_at_block_size(format_name, img, block_size)
self.assertTrue(fmt.format_match,
'Failed to match %s at size %i block %i' % (
format_name, image_size, block_size))
self.assertEqual(0, fmt.virtual_size,
('Calculated a virtual size for a corrupt %s at '
'size %i block %i') % (format_name, image_size,
block_size))
def test_vmdk_bad_descriptor_offset(self):
self._test_vmdk_bad_descriptor_offset()
def test_vmdk_bad_descriptor_offset_stream_optimized(self):
self._test_vmdk_bad_descriptor_offset(subformat='streamOptimized')
def _test_vmdk_bad_descriptor_mem_limit(self, subformat=None):
format_name = 'vmdk'
image_size = 5 * units.Mi
virtual_size = 5 * units.Mi
descriptorOffsetAddr = 0x1c
descriptorSizeAddr = descriptorOffsetAddr + 8
twoMBInSectors = (2 << 20) // 512
# We need a big VMDK because otherwise we will not have enough data to
# fill-up the CaptureRegion.
img = self._create_allocated_vmdk(image_size // units.Mi,
subformat=subformat)
# Corrupt the end of descriptor address so it "ends" at 2MB
fd = open(img, 'r+b')
fd.seek(descriptorSizeAddr)
fd.write(struct.pack('<Q', twoMBInSectors))
fd.close()
# Read the format in various sizes, some of which will read whole
# sections in a single read, others will be completely unaligned, etc.
for block_size in (64 * units.Ki, 512, 17, 1 * units.Mi):
fmt = self._test_format_at_block_size(format_name, img, block_size)
self.assertTrue(fmt.format_match,
'Failed to match %s at size %i block %i' % (
format_name, image_size, block_size))
self.assertEqual(virtual_size, fmt.virtual_size,
('Failed to calculate size for %s at size %i '
'block %i') % (format_name, image_size,
block_size))
memory = sum(fmt.context_info.values())
self.assertLess(memory, 1.5 * units.Mi,
'Format used more than 1.5MiB of memory: %s' % (
fmt.context_info))
def test_vmdk_bad_descriptor_mem_limit(self):
self._test_vmdk_bad_descriptor_mem_limit()
def test_vmdk_bad_descriptor_mem_limit_stream_optimized(self):
self._test_vmdk_bad_descriptor_mem_limit(subformat='streamOptimized')
def test_qcow2_safety_checks(self):
# Create backing and data-file names (and initialize the backing file)
backing_fn = tempfile.mktemp(prefix='backing')
self._created_files.append(backing_fn)
with open(backing_fn, 'w') as f:
f.write('foobar')
data_fn = tempfile.mktemp(prefix='data')
self._created_files.append(data_fn)
# A qcow with no backing or data file is safe
fn = self._create_img('qcow2', 5 * units.Mi, None)
inspector = format_inspector.QcowInspector.from_file(fn)
self.assertTrue(inspector.safety_check())
# A backing file makes it unsafe
fn = self._create_img('qcow2', 5 * units.Mi, None,
backing_file=backing_fn)
inspector = format_inspector.QcowInspector.from_file(fn)
self.assertFalse(inspector.safety_check())
# A data-file makes it unsafe
fn = self._create_img('qcow2', 5 * units.Mi,
options={'data_file': data_fn,
'data_file_raw': 'on'})
inspector = format_inspector.QcowInspector.from_file(fn)
self.assertFalse(inspector.safety_check())
# Trying to load a non-QCOW file is an error
self.assertRaises(format_inspector.ImageFormatError,
format_inspector.QcowInspector.from_file,
backing_fn)
def test_qcow2_feature_flag_checks(self):
data = bytearray(512)
data[0:4] = b'QFI\xFB'
inspector = format_inspector.QcowInspector()
inspector.region('header').data = data
# All zeros, no feature flags - all good
self.assertFalse(inspector.has_unknown_features)
# A feature flag set in the first byte (highest-order) is not
# something we know about, so fail.
data[0x48] = 0x01
self.assertTrue(inspector.has_unknown_features)
# The first bit in the last byte (lowest-order) is known (the dirty
# bit) so that should pass
data[0x48] = 0x00
data[0x4F] = 0x01
self.assertFalse(inspector.has_unknown_features)
# Currently (as of 2024), the high-order feature flag bit in the low-
# order byte is not assigned, so make sure we reject it.
data[0x4F] = 0x80
self.assertTrue(inspector.has_unknown_features)
def test_vdi(self):
self._test_format('vdi')
def _test_format_with_invalid_data(self, format_name):
fmt = format_inspector.get_inspector(format_name)()
wrapper = format_inspector.InfoWrapper(open(__file__, 'rb'), fmt)
while True:
chunk = wrapper.read(32)
if not chunk:
break
wrapper.close()
self.assertFalse(fmt.format_match)
self.assertEqual(0, fmt.virtual_size)
memory = sum(fmt.context_info.values())
self.assertLess(memory, 512 * units.Ki,
'Format used more than 512KiB of memory: %s' % (
fmt.context_info))
def test_qcow2_invalid(self):
self._test_format_with_invalid_data('qcow2')
def test_vhd_invalid(self):
self._test_format_with_invalid_data('vhd')
def test_vhdx_invalid(self):
self._test_format_with_invalid_data('vhdx')
def test_vmdk_invalid(self):
self._test_format_with_invalid_data('vmdk')
def test_vdi_invalid(self):
self._test_format_with_invalid_data('vdi')
def test_vmdk_invalid_type(self):
fmt = format_inspector.get_inspector('vmdk')()
wrapper = format_inspector.InfoWrapper(open(__file__, 'rb'), fmt)
while True:
chunk = wrapper.read(32)
if not chunk:
break
wrapper.close()
fake_rgn = mock.MagicMock()
fake_rgn.complete = True
fake_rgn.data = b'foocreateType="someunknownformat"bar'
with mock.patch.object(fmt, 'has_region', return_value=True):
with mock.patch.object(fmt, 'region', return_value=fake_rgn):
self.assertEqual(0, fmt.virtual_size)
class TestFormatInspectorInfra(test.NoDBTestCase):
def _test_capture_region_bs(self, bs):
data = b''.join(chr(x).encode() for x in range(ord('A'), ord('z')))
regions = [
format_inspector.CaptureRegion(3, 9),
format_inspector.CaptureRegion(0, 256),
format_inspector.CaptureRegion(32, 8),
]
for region in regions:
# None of them should be complete yet
self.assertFalse(region.complete)
pos = 0
for i in range(0, len(data), bs):
chunk = data[i:i + bs]
pos += len(chunk)
for region in regions:
region.capture(chunk, pos)
self.assertEqual(data[3:12], regions[0].data)
self.assertEqual(data[0:256], regions[1].data)
self.assertEqual(data[32:40], regions[2].data)
# The small regions should be complete
self.assertTrue(regions[0].complete)
self.assertTrue(regions[2].complete)
# This region extended past the available data, so not complete
self.assertFalse(regions[1].complete)
def test_capture_region(self):
for block_size in (1, 3, 7, 13, 32, 64):
self._test_capture_region_bs(block_size)
def _get_wrapper(self, data):
source = io.BytesIO(data)
fake_fmt = mock.create_autospec(format_inspector.get_inspector('raw'))
return format_inspector.InfoWrapper(source, fake_fmt)
def test_info_wrapper_file_like(self):
data = b''.join(chr(x).encode() for x in range(ord('A'), ord('z')))
wrapper = self._get_wrapper(data)
read_data = b''
while True:
chunk = wrapper.read(8)
if not chunk:
break
read_data += chunk
self.assertEqual(data, read_data)
def test_info_wrapper_iter_like(self):
data = b''.join(chr(x).encode() for x in range(ord('A'), ord('z')))
wrapper = self._get_wrapper(data)
read_data = b''
for chunk in wrapper:
read_data += chunk
self.assertEqual(data, read_data)
def test_info_wrapper_file_like_eats_error(self):
wrapper = self._get_wrapper(b'123456')
wrapper._format.eat_chunk.side_effect = Exception('fail')
data = b''
while True:
chunk = wrapper.read(3)
if not chunk:
break
data += chunk
# Make sure we got all the data despite the error
self.assertEqual(b'123456', data)
# Make sure we only called this once and never again after
# the error was raised
wrapper._format.eat_chunk.assert_called_once_with(b'123')
def test_info_wrapper_iter_like_eats_error(self):
fake_fmt = mock.create_autospec(format_inspector.get_inspector('raw'))
wrapper = format_inspector.InfoWrapper(iter([b'123', b'456']),
fake_fmt)
fake_fmt.eat_chunk.side_effect = Exception('fail')
data = b''
for chunk in wrapper:
data += chunk
# Make sure we got all the data despite the error
self.assertEqual(b'123456', data)
# Make sure we only called this once and never again after
# the error was raised
fake_fmt.eat_chunk.assert_called_once_with(b'123')
def test_get_inspector(self):
self.assertEqual(format_inspector.QcowInspector,
format_inspector.get_inspector('qcow2'))
self.assertIsNone(format_inspector.get_inspector('foo'))
class TestFormatInspectorsTargeted(test.NoDBTestCase):
def _make_vhd_meta(self, guid_raw, item_length):
# Meta region header, padded to 32 bytes
data = struct.pack('<8sHH', b'metadata', 0, 1)
data += b'0' * 20
# Metadata table entry, 16-byte GUID, 12-byte information,
# padded to 32-bytes
data += guid_raw
data += struct.pack('<III', 256, item_length, 0)
data += b'0' * 6
return data
def test_vhd_table_over_limit(self):
ins = format_inspector.VHDXInspector()
meta = format_inspector.CaptureRegion(0, 0)
desired = b'012345678ABCDEF0'
# This is a poorly-crafted image that specifies a larger table size
# than is allowed
meta.data = self._make_vhd_meta(desired, 33 * 2048)
ins.new_region('metadata', meta)
new_region = ins._find_meta_entry(ins._guid(desired))
# Make sure we clamp to our limit of 32 * 2048
self.assertEqual(
format_inspector.VHDXInspector.VHDX_METADATA_TABLE_MAX_SIZE,
new_region.length)
def test_vhd_table_under_limit(self):
ins = format_inspector.VHDXInspector()
meta = format_inspector.CaptureRegion(0, 0)
desired = b'012345678ABCDEF0'
meta.data = self._make_vhd_meta(desired, 16 * 2048)
ins.new_region('metadata', meta)
new_region = ins._find_meta_entry(ins._guid(desired))
# Table size was under the limit, make sure we get it back
self.assertEqual(16 * 2048, new_region.length)