# -*- coding: utf-8 -*-
# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2018 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# http://cloudlinux.com/docs/LICENSE.TXT
#
import inspect
import logging
import os
import sys
import raven
import time
from io import StringIO
from contextlib import contextmanager
from functools import wraps
logger = logging.getLogger(__name__)
LISTENERS_DIRECTORY = '/usr/share/cloudlinux/hooks/listeners/'
@contextmanager
def capture_output(stdo, stde):
stdout = sys.stdout
stderr = sys.stderr
try:
sys.stdout = stdo or StringIO()
sys.stderr = stde or StringIO()
yield
finally:
sys.stdout = stdout
sys.stderr = stderr
def hook_method(func):
"""
Magic decorator that calls all subclass methods
that override base decorated one.
Requirements:
- subclass must be defined in .py file in LISTENERS_DIRECTORY
- subclass must NOT start with '_' char
- subclass must override base event method (the one with '@hook_method')
"""
@wraps(func)
def _wrapped(self, *args, **kwargs):
# this only return direct subclasses, so we can't make `proxies` now
for subclass in self.__class__.__subclasses__():
listener_path = os.path.dirname(inspect.getmodule(subclass).__file__)
# skip child if it is not in expected directory
if os.path.normpath(LISTENERS_DIRECTORY) != os.path.normpath(listener_path):
logger.warning('%s is not in %s directory; it is in %s,'
' skip', subclass, LISTENERS_DIRECTORY, listener_path)
continue
# skip internal classes
if subclass.__name__.startswith('_'):
continue
# magic: get method only if it is defined in child (NOT in parent)
listener = getattr(subclass(), func.__name__)
if getattr(listener, 'is_magic_method', False):
logger.debug('skip %s is not implemented in %s',
func.__name__, subclass.__name__)
continue
logger.info('executing %s:%s', func.__name__, subclass.__name__)
now = time.time()
stdout, stderr = StringIO(), StringIO()
try:
with capture_output(stdout, stderr):
listener(*args, **kwargs)
except Exception:
# use Raven carefully and only in places where
# you sure that sentry is already initialized
raven.base.Raven.captureException(
fingerprint=['{{ default }}', subclass.__name__, func.__name__],
extra={'stdout': stdout.getvalue(), 'stderr': stderr.getvalue()}
)
logger.warning('listener %s:%s crashed', subclass.__name__, func.__name__, exc_info=1)
finally:
elapsed = time.time() - now
stdout_str = stdout.getvalue()
if stdout_str:
logger.info('captured stdout of %s:%s\n~BEGIN OUTPUT~\n%s\n~END OUTPUT~\n',
func.__name__, subclass.__name__, stdout_str)
stderr_str = stderr.getvalue()
if stderr_str:
logger.debug('captured stderr of %s:%s\n~BEGIN OUTPUT~\n%s\n~END OUTPUT~\n',
func.__name__, subclass.__name__, stderr_str)
logger.debug('running %s: %.4f elapsed', func.__name__, elapsed)
logger.info('%s executed by the user with uid %s and gid %s',
func.__name__, os.geteuid(), os.getegid())
logger.info('ended %s(%s, %s)', func.__name__, args, kwargs)
# special marker to determine overrided methods
_wrapped.is_magic_method = True
return _wrapped
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