93 lines
2.7 KiB
Python
93 lines
2.7 KiB
Python
# Copyright 2018-2022 Canonical, Ltd.
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#
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation, version 3.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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import contextlib
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import datetime
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import grp
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import logging
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import os
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import shutil
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import tempfile
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import yaml
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_DEF_PERMS_FILE = 0o600
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_DEF_GROUP = "root"
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log = logging.getLogger("subiquitycore.file_util")
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def set_log_perms(target, *, group_write=False, mode=None, group=_DEF_GROUP):
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if os.getuid() != 0:
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log.warning(
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"set_log_perms: running as non-root - not adjusting"
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+ " group owner or permissions for "
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+ target
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)
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return
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if mode is None:
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mode = _DEF_PERMS_FILE
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if os.path.isdir(target):
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mode |= 0o110
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if group_write:
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mode |= 0o020
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os.chmod(target, mode)
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os.chown(target, 0, grp.getgrnam(group).gr_gid)
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@contextlib.contextmanager
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def open_perms(filename, **kwargs):
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tf = None
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try:
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dirname = os.path.dirname(filename)
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os.makedirs(dirname, exist_ok=True)
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tf = tempfile.NamedTemporaryFile(dir=dirname, delete=False, mode="w")
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yield tf
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tf.close()
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set_log_perms(tf.name, **kwargs)
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os.rename(tf.name, filename)
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except OSError as e:
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if tf is not None:
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os.unlink(tf.name)
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raise e
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def write_file(filename, content, **kwargs):
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with open_perms(filename, **kwargs) as tf:
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tf.write(content)
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def generate_timestamped_header() -> str:
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now = datetime.datetime.now(datetime.timezone.utc).replace(tzinfo=None)
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return f"# Autogenerated by Subiquity: {now} UTC\n"
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def generate_config_yaml(filename, content, **kwargs):
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with open_perms(filename, **kwargs) as tf:
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tf.write(generate_timestamped_header())
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tf.write(yaml.dump(content))
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def copy_file_if_exists(source: str, target: str):
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"""If source exists, copy to destination. Ignore error that dest may be a
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duplicate. Create destination parent dirs as needed."""
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if not os.path.exists(source):
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return
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dirname = os.path.dirname(target)
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os.makedirs(dirname, exist_ok=True)
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try:
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shutil.copyfile(source, target)
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except shutil.SameFileError:
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pass
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