/snap/core24/1587/usr/lib/python3/dist-packages/cloudinit
Edit: /snap/core24/1587/usr/lib/python3/dist-packages/cloudinit/atomic_helper.py (2860B)
# This file is part of cloud-init. See LICENSE file for license information.
import json
import logging
import os
import stat
import tempfile
from base64 import b64decode, b64encode
from cloudinit import performance, util
_DEF_PERMS = 0o644
LOG = logging.getLogger(__name__)
@performance.timed("Base64 decoding")
def b64d(source):
"""base64 decode data
:param source: a bytes or str to decode
:return: base64 as a decoded str if utf-8 encoded, otherwise bytes
"""
decoded = b64decode(source)
try:
return decoded.decode("utf-8")
except UnicodeDecodeError:
return decoded
@performance.timed("Base64 encoding")
def b64e(source):
"""base64 encode data
:param source: a bytes or str to decode
:return: base64 encoded str
"""
if not isinstance(source, bytes):
source = source.encode("utf-8")
return b64encode(source).decode("utf-8")
def write_file(
filename, content, mode=_DEF_PERMS, omode="wb", preserve_mode=False
):
"""open filename in mode omode, write content, set permissions to mode"""
with performance.Timed(f"Writing {filename}"):
return _write_file(filename, content, mode, omode, preserve_mode)
def _write_file(
filename, content, mode=_DEF_PERMS, omode="wb", preserve_mode=False
):
if preserve_mode:
try:
file_stat = os.stat(filename)
mode = stat.S_IMODE(file_stat.st_mode)
except OSError:
pass
tf = None
try:
dirname = os.path.dirname(filename)
util.ensure_dir(dirname)
tf = tempfile.NamedTemporaryFile(dir=dirname, delete=False, mode=omode)
LOG.debug(
"Atomically writing to file %s (via temporary file %s) - %s: [%o]"
" %d bytes/chars",
filename,
tf.name,
omode,
mode,
len(content),
)
tf.write(content)
tf.close()
os.chmod(tf.name, mode)
os.rename(tf.name, filename)
except Exception as e:
if tf is not None:
os.unlink(tf.name)
raise e
def json_serialize_default(_obj):
"""Handler for types which aren't json serializable."""
try:
return "ci-b64:{0}".format(b64e(_obj))
except AttributeError:
return "Warning: redacted unserializable type {0}".format(type(_obj))
@performance.timed("Dumping json")
def json_dumps(data):
"""Return data in nicely formatted json."""
return json.dumps(
data,
indent=1,
sort_keys=True,
separators=(",", ": "),
default=json_serialize_default,
)
def write_json(filename, data, mode=_DEF_PERMS):
# dump json representation of data to file filename.
return write_file(
filename,
json_dumps(data) + "\n",
omode="w",
mode=mode,
)