def test_yum_is_dnf(self):
# Setup for yum not being the same as dnf, modeled after fb
with temp_dir() as td:
yum_path = Path(td / 'yum').touch()
with mock.patch('shutil.which') as mock_which:
mock_which.return_value = None
self.assertFalse(yum_is_dnf())
mock_which.return_value = yum_path.decode()
self.assertFalse(yum_is_dnf())
# Setup for yum being the same as dnf, modeled after fedora
# where `/bin/yum -> dnf-3`
with temp_dir() as td:
dnf_name = 'dnf-3'
dnf_path = Path(td / dnf_name).touch()
yum_path = td / 'yum'
# Symlink to the name for a relative symlink that ends up
# as yum -> dnf-3
os.symlink(dnf_name, yum_path)
with mock.patch('shutil.which') as mock_which:
mock_paths = {dnf_name: dnf_path, 'yum': yum_path}
mock_which.side_effect = lambda p: mock_paths[p].decode()
self.assertTrue(yum_is_dnf())
def _yum_using_build_appliance(
*,
build_appliance: Subvol,
nspawn_args: List[str],
install_root: Path,
protected_paths: Iterable[str],
yum_args: List[str],
preserve_yum_cache: bool,
) -> None:
work_dir = '/work' + base64.urlsafe_b64encode(
uuid.uuid4().bytes # base64 instead of hex saves 10 bytes
).decode().strip('=')
mount_var_cache_yum = '' if preserve_yum_cache else f'''
mkdir -p {work_dir}/var/cache/yum ; \
mount --bind /var/cache/yum {work_dir}/var/cache/yum ;
'''
opts = nspawn_in_subvol_parse_opts([
'--layer',
'UNUSED',
'--user',
'root',
# You can see below --no-private-network in conjunction with
# --cap-net-admin. CAP_NET_ADMIN is not intended to administer the
# host's network stack. See how yum_from_snapshot() brings loopback
# interface up under protection of "unshare --net".
'--cap-net-admin',
'--no-private-network',
'--bindmount-rw',
install_root.decode(),
work_dir,
*nspawn_args,
'--',
'sh',
'-uec',
f'''
{mount_var_cache_yum}
/yum-from-snapshot \
{' '.join(
'--protected-path=' + shlex.quote(p) for p in protected_paths
)} \
--install-root {work_dir} \
-- {' '.join(shlex.quote(arg) for arg in yum_args)}
''',
])
# Don't pollute stdout with logging
nspawn_in_subvol(build_appliance, opts, stdout=sys.stderr)