mirror of
https://github.com/ansible-collections/community.general.git
synced 2026-02-04 16:01:55 +00:00
3478863ef0
* Resolve E713 and E714 (not in/is tests). * Address UP018 (unnecessary str call). * UP045 requires Python 3.10+. * Address UP007 (X | Y for type annotations). * Address UP035 (import Callable from collections.abc). * Address UP006 (t.Dict -> dict). * Address UP009 (UTF-8 encoding comment). * Address UP034 (extraneous parantheses). * Address SIM910 (dict.get() with None default). * Address F401 (unused import). * Address UP020 (use builtin open). * Address B009 and B010 (getattr/setattr with constant name). * Address SIM300 (Yoda conditions). * UP029 isn't in use anyway. * Address FLY002 (static join). * Address B034 (re.sub positional args). * Address B020 (loop variable overrides input). * Address B017 (assert raise Exception). * Address SIM211 (if expression with false/true). * Address SIM113 (enumerate for loop). * Address UP036 (sys.version_info checks). * Remove unnecessary UP039. * Address SIM201 (not ==). * Address SIM212 (if expr with twisted arms). * Add changelog fragment. * Reformat.
105 lines
3.2 KiB
Python
105 lines
3.2 KiB
Python
# Copyright (c) 2018, Ansible Project
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# Simplified BSD License (see licenses/simplified_bsd.txt or https://opensource.org/licenses/BSD-2-Clause)
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# SPDX-License-Identifier: BSD-2-Clause
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# NOTE:
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# This has been vendored from ansible.module_utils.common.file. This code has been removed from there for ansible-core 2.16.
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from __future__ import annotations
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import os
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import stat
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import time
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import fcntl
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from contextlib import contextmanager
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class LockTimeout(Exception):
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pass
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class FileLock:
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"""
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Currently FileLock is implemented via fcntl.flock on a lock file, however this
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behaviour may change in the future. Avoid mixing lock types fcntl.flock,
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fcntl.lockf and module_utils.common.file.FileLock as it will certainly cause
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unwanted and/or unexpected behaviour
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"""
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def __init__(self):
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self.lockfd = None
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@contextmanager
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def lock_file(self, path, tmpdir, lock_timeout=None):
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"""
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Context for lock acquisition
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"""
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try:
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self.set_lock(path, tmpdir, lock_timeout)
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yield
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finally:
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self.unlock()
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def set_lock(self, path, tmpdir, lock_timeout=None):
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"""
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Create a lock file based on path with flock to prevent other processes
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using given path.
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Please note that currently file locking only works when it is executed by
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the same user, for example single user scenarios
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:kw path: Path (file) to lock
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:kw tmpdir: Path where to place the temporary .lock file
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:kw lock_timeout:
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Wait n seconds for lock acquisition, fail if timeout is reached.
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0 = Do not wait, fail if lock cannot be acquired immediately,
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Default is None, wait indefinitely until lock is released.
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:returns: True
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"""
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lock_path = os.path.join(tmpdir, f"ansible-{os.path.basename(path)}.lock")
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l_wait = 0.1
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self.lockfd = open(lock_path, "w")
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if lock_timeout <= 0:
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fcntl.flock(self.lockfd, fcntl.LOCK_EX | fcntl.LOCK_NB)
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os.chmod(lock_path, stat.S_IWRITE | stat.S_IREAD)
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return True
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if lock_timeout:
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e_secs = 0
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while e_secs < lock_timeout:
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try:
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fcntl.flock(self.lockfd, fcntl.LOCK_EX | fcntl.LOCK_NB)
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os.chmod(lock_path, stat.S_IWRITE | stat.S_IREAD)
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return True
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except BlockingIOError:
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time.sleep(l_wait)
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e_secs += l_wait
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continue
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self.lockfd.close()
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raise LockTimeout(f"{lock_timeout} sec")
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fcntl.flock(self.lockfd, fcntl.LOCK_EX)
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os.chmod(lock_path, stat.S_IWRITE | stat.S_IREAD)
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return True
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def unlock(self):
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"""
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Make sure lock file is available for everyone and Unlock the file descriptor
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locked by set_lock
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:returns: True
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"""
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if not self.lockfd:
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return True
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try:
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fcntl.flock(self.lockfd, fcntl.LOCK_UN)
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self.lockfd.close()
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except ValueError: # file wasn't opened, let context manager fail gracefully
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pass
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return True
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