pre-commit/tests/languages/docker_test.py
Matthew Hughes 466f6c4a39 Fix permission errors for mounts in rootless docker
By running containers in a rootless docker context as root. This is
because user and group IDs are remapped in the user namespaces uses by
rootless docker, and it's unlikely that the current user ID will map to
the same ID under this remap (see docs[1] for some more details).
Specifically, it means ownership of mounted volumes will not be for the
current user and trying to write can result in permission errors.

This change borrows heavily from an existing PR[2].

The output format of `docker system info` I don't think is
documented/guaranteed anywhere, but it should corresponding to the
format of a `/info` API request to Docker[3]

The added test _hopes_ to avoid regressions in this behaviour, but since
tests aren't run in a rootless docker context on the PR checks (and I
couldn't find an easy way to make it the case) there's still a risk of
regressions sneaking in.

Link: https://docs.docker.com/engine/security/rootless/ [1]
Link: https://github.com/pre-commit/pre-commit/pull/1484/ [2]
Link: https://docs.docker.com/reference/api/engine/version/v1.48/#tag/System/operation/SystemAuth [3]
Co-authored-by: Kurt von Laven <Kurt-von-Laven@users.noreply.github.com>
Co-authored-by: Fabrice Flore-Thébault <ffloreth@redhat.com>
2025-05-23 17:01:10 -04:00

244 lines
7.6 KiB
Python

from __future__ import annotations
import builtins
import json
import ntpath
import os.path
import posixpath
from unittest import mock
import pytest
from pre_commit.languages import docker
from pre_commit.util import CalledProcessError
from testing.language_helpers import run_language
from testing.util import xfailif_windows
DOCKER_CGROUP_EXAMPLE = b'''\
12:hugetlb:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
11:blkio:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
10:freezer:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
9:cpu,cpuacct:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
8:pids:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
7:rdma:/
6:net_cls,net_prio:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
5:cpuset:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
4:devices:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
3:memory:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
2:perf_event:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
1:name=systemd:/docker/c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7
0::/system.slice/containerd.service
''' # noqa: E501
# The ID should match the above cgroup example.
CONTAINER_ID = 'c33988ec7651ebc867cb24755eaf637a6734088bc7eef59d5799293a9e5450f7' # noqa: E501
NON_DOCKER_CGROUP_EXAMPLE = b'''\
12:perf_event:/
11:hugetlb:/
10:devices:/
9:blkio:/
8:rdma:/
7:cpuset:/
6:cpu,cpuacct:/
5:freezer:/
4:memory:/
3:pids:/
2:net_cls,net_prio:/
1:name=systemd:/init.scope
0::/init.scope
'''
def test_docker_fallback_user():
def invalid_attribute():
raise AttributeError
with mock.patch.multiple(
'os', create=True,
getuid=invalid_attribute,
getgid=invalid_attribute,
):
assert docker.get_docker_user() == ()
@pytest.fixture(autouse=True)
def _avoid_cache():
with mock.patch.object(
docker,
'_is_rootless',
docker._is_rootless.__wrapped__,
):
yield
@pytest.mark.parametrize(
'info_ret',
(
(0, b'{"SecurityOptions": ["name=rootless","name=cgroupns"]}', b''),
(0, b'{"host": {"security": {"rootless": true}}}', b''),
),
)
def test_docker_user_rootless(info_ret):
with mock.patch.object(docker, 'cmd_output_b', return_value=info_ret):
assert docker.get_docker_user() == ()
@pytest.mark.parametrize(
'info_ret',
(
(0, b'{"SecurityOptions": ["name=cgroupns"]}', b''),
(0, b'{"host": {"security": {"rootless": false}}}', b''),
(0, b'{"respone_from_some_other_container_engine": true}', b''),
(1, b'', b''),
),
)
def test_docker_user_non_rootless(info_ret):
with mock.patch.object(docker, 'cmd_output_b', return_value=info_ret):
assert docker.get_docker_user() != ()
def test_in_docker_no_file():
with mock.patch.object(builtins, 'open', side_effect=FileNotFoundError):
assert docker._is_in_docker() is False
def _mock_open(data):
return mock.patch.object(
builtins,
'open',
new_callable=mock.mock_open,
read_data=data,
)
def test_in_docker_docker_in_file():
with _mock_open(DOCKER_CGROUP_EXAMPLE):
assert docker._is_in_docker() is True
def test_in_docker_docker_not_in_file():
with _mock_open(NON_DOCKER_CGROUP_EXAMPLE):
assert docker._is_in_docker() is False
def test_get_container_id():
with _mock_open(DOCKER_CGROUP_EXAMPLE):
assert docker._get_container_id() == CONTAINER_ID
def test_get_container_id_failure():
with _mock_open(b''), pytest.raises(RuntimeError):
docker._get_container_id()
def test_get_docker_path_not_in_docker_returns_same():
with mock.patch.object(docker, '_is_in_docker', return_value=False):
assert docker._get_docker_path('abc') == 'abc'
@pytest.fixture
def in_docker():
with mock.patch.object(docker, '_is_in_docker', return_value=True):
with mock.patch.object(
docker, '_get_container_id', return_value=CONTAINER_ID,
):
yield
def _linux_commonpath():
return mock.patch.object(os.path, 'commonpath', posixpath.commonpath)
def _nt_commonpath():
return mock.patch.object(os.path, 'commonpath', ntpath.commonpath)
def _docker_output(out):
ret = (0, out, b'')
return mock.patch.object(docker, 'cmd_output_b', return_value=ret)
def test_get_docker_path_in_docker_no_binds_same_path(in_docker):
docker_out = json.dumps([{'Mounts': []}]).encode()
with _docker_output(docker_out):
assert docker._get_docker_path('abc') == 'abc'
def test_get_docker_path_in_docker_binds_path_equal(in_docker):
binds_list = [{'Source': '/opt/my_code', 'Destination': '/project'}]
docker_out = json.dumps([{'Mounts': binds_list}]).encode()
with _linux_commonpath(), _docker_output(docker_out):
assert docker._get_docker_path('/project') == '/opt/my_code'
def test_get_docker_path_in_docker_binds_path_complex(in_docker):
binds_list = [{'Source': '/opt/my_code', 'Destination': '/project'}]
docker_out = json.dumps([{'Mounts': binds_list}]).encode()
with _linux_commonpath(), _docker_output(docker_out):
path = '/project/test/something'
assert docker._get_docker_path(path) == '/opt/my_code/test/something'
def test_get_docker_path_in_docker_no_substring(in_docker):
binds_list = [{'Source': '/opt/my_code', 'Destination': '/project'}]
docker_out = json.dumps([{'Mounts': binds_list}]).encode()
with _linux_commonpath(), _docker_output(docker_out):
path = '/projectSuffix/test/something'
assert docker._get_docker_path(path) == path
def test_get_docker_path_in_docker_binds_path_many_binds(in_docker):
binds_list = [
{'Source': '/something_random', 'Destination': '/not-related'},
{'Source': '/opt/my_code', 'Destination': '/project'},
{'Source': '/something-random-2', 'Destination': '/not-related-2'},
]
docker_out = json.dumps([{'Mounts': binds_list}]).encode()
with _linux_commonpath(), _docker_output(docker_out):
assert docker._get_docker_path('/project') == '/opt/my_code'
def test_get_docker_path_in_docker_windows(in_docker):
binds_list = [{'Source': r'c:\users\user', 'Destination': r'c:\folder'}]
docker_out = json.dumps([{'Mounts': binds_list}]).encode()
with _nt_commonpath(), _docker_output(docker_out):
path = r'c:\folder\test\something'
expected = r'c:\users\user\test\something'
assert docker._get_docker_path(path) == expected
def test_get_docker_path_in_docker_docker_in_docker(in_docker):
# won't be able to discover "self" container in true docker-in-docker
err = CalledProcessError(1, (), b'', b'')
with mock.patch.object(docker, 'cmd_output_b', side_effect=err):
assert docker._get_docker_path('/project') == '/project'
@xfailif_windows # pragma: win32 no cover
def test_docker_hook(tmp_path):
dockerfile = '''\
FROM ubuntu:22.04
CMD ["echo", "This is overwritten by the entry"']
'''
tmp_path.joinpath('Dockerfile').write_text(dockerfile)
ret = run_language(tmp_path, docker, 'echo hello hello world')
assert ret == (0, b'hello hello world\n')
@xfailif_windows # pragma: win32 no cover
def test_docker_hook_mount_permissions(tmp_path):
dockerfile = '''\
FROM ubuntu:22.04
'''
tmp_path.joinpath('Dockerfile').write_text(dockerfile)
retcode, _ = run_language(tmp_path, docker, 'touch', ('README.md',))
assert retcode == 0