# This file is part of cloud-init. See LICENSE file for license information. import json import logging import os import stat import tempfile _DEF_PERMS = 0o644 LOG = logging.getLogger(__name__) def write_file( filename, content, mode=_DEF_PERMS, omode="wb", preserve_mode=False ): # open filename in mode 'omode', write content, set permissions to 'mode' if preserve_mode: try: file_stat = os.stat(filename) mode = stat.S_IMODE(file_stat.st_mode) except OSError: pass tf = None try: tf = tempfile.NamedTemporaryFile( dir=os.path.dirname(filename), 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 write_json(filename, data, mode=_DEF_PERMS): # dump json representation of data to file filename. return write_file( filename, json.dumps(data, indent=1, sort_keys=True) + "\n", omode="w", mode=mode, ) # vi: ts=4 expandtab