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| -rw-r--r-- | cloudinit/monkey_patch.py | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/cloudinit/monkey_patch.py b/cloudinit/monkey_patch.py new file mode 100644 index 00000000..24b472ba --- /dev/null +++ b/cloudinit/monkey_patch.py @@ -0,0 +1,74 @@ +# vi: ts=4 expandtab +# +# Copyright (C) 2012 Canonical Ltd. +# Copyright (C) 2012 Yahoo! Inc. +# +# Author: Scott Moser <scott.moser@canonical.com> +# Author: Joshua Harlow <harlowja@yahoo-inc.com> +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License version 3, as +# published by the Free Software Foundation. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see <http://www.gnu.org/licenses/>. + +import logging +import sys + +FALL_FORMAT = 'FALLBACK: %(asctime)s - %(filename)s[%(levelname)s]: %(message)s' + +Handler = logging.Handler + +class QuietStreamHandler(Handler): + def handleError(self, record): + pass + + +class FallbackHandler(Handler): + def __init__(self, level=logging.NOTSET, fb_handler=None): + super(FallbackHandler, self).__init__(level) + if not fb_handler: + self.fallback_handler = QuietStreamHandler(sys.stderr) + else: + self.fallback_handler = fb_handler + self.fallback_handler.setFormatter(logging.Formatter(FALL_FORMAT)) + self.fallback_handler.setLevel(level) + + def flush(self): + super(FallbackHandler, self).flush() + self.fallback_handler.flush() + + def close(self): + super(FallbackHandler, self).close(self) + self.fallback_handler.close() + + def setLevel(self, level): + super(FallbackHandler, self).setLevel(self, level) + self.fallback_logger.setLevel(level) + + def handleError(self, record): + try: + self.fallback_logger.handle(record) + # Always ensure this one is flushed... + self.fallback_logger.flush() + except: + pass + + +def _patch_logging(): + # Replace handler with one that will be more + # tolerant of errors in that it can avoid + # re-notifying on exceptions and when errors + # do occur, it can at least try to write to + # sys.stderr using a fallback logger + logging.Handler = FallbackHandler + + +def patch(): + _patch_logging() |