CasperSecurity
# This file is part of cloud-init. See LICENSE file for license information.
import contextlib
import errno
import logging
import os
import shutil
import tempfile
from cloudinit import util
LOG = logging.getLogger(__name__)
_ROOT_TMPDIR = "/run/cloud-init/tmp"
_EXE_ROOT_TMPDIR = "/var/tmp/cloud-init"
def get_tmp_ancestor(odir=None, needs_exe: bool = False):
if odir is not None:
return odir
if needs_exe:
return _EXE_ROOT_TMPDIR
if os.getuid() == 0:
return _ROOT_TMPDIR
return os.environ.get("TMPDIR", "/tmp")
def _tempfile_dir_arg(odir=None, needs_exe: bool = False):
"""Return the proper 'dir' argument for tempfile functions.
When root, cloud-init will use /run/cloud-init/tmp to avoid
any cleaning that a distro boot might do on /tmp (such as
systemd-tmpfiles-clean).
If the caller of this function (mkdtemp or mkstemp) was provided
with a 'dir' argument, then that is respected.
@param odir: original 'dir' arg to 'mkdtemp' or other.
@param needs_exe: Boolean specifying whether or not exe permissions are
needed for tempdir. This is needed because /run is mounted noexec.
"""
tdir = get_tmp_ancestor(odir, needs_exe)
if not os.path.isdir(tdir):
os.makedirs(tdir)
os.chmod(tdir, 0o1777)
if needs_exe:
if util.has_mount_opt(tdir, "noexec"):
LOG.warning(
"Requested temporal dir with exe permission `%s` is"
" mounted as noexec",
tdir,
)
return tdir
def ExtendedTemporaryFile(**kwargs):
kwargs["dir"] = _tempfile_dir_arg()
fh = tempfile.NamedTemporaryFile(**kwargs)
# Replace its unlink with a quiet version
# that does not raise errors when the
# file to unlink has been unlinked elsewhere..
def _unlink_if_exists(path):
try:
os.unlink(path)
except OSError as e:
if e.errno != errno.ENOENT:
raise e
fh.unlink = _unlink_if_exists
# Add a new method that will unlink
# right 'now' but still lets the exit
# method attempt to remove it (which will
# not throw due to our del file being quiet
# about files that are not there)
def unlink_now():
fh.unlink(fh.name)
setattr(fh, "unlink_now", unlink_now)
return fh
@contextlib.contextmanager
def tempdir(rmtree_ignore_errors=False, **kwargs):
# This seems like it was only added in python 3.2
# Make it since its useful...
# See: http://bugs.python.org/file12970/tempdir.patch
tdir = mkdtemp(**kwargs)
try:
yield tdir
finally:
shutil.rmtree(tdir, ignore_errors=rmtree_ignore_errors)
def mkdtemp(dir=None, needs_exe: bool = False, **kwargs):
dir = _tempfile_dir_arg(dir, needs_exe)
return tempfile.mkdtemp(dir=dir, **kwargs)
def mkstemp(dir=None, needs_exe: bool = False, **kwargs):
dir = _tempfile_dir_arg(dir, needs_exe)
return tempfile.mkstemp(dir=dir, **kwargs)