133 lines
3.7 KiB
Python
133 lines
3.7 KiB
Python
# Copyright 2021 Canonical Ltd.
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License");
|
|
# you may not use this file except in compliance with the License.
|
|
# You may obtain a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS,
|
|
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
# See the License for the specific language governing permissions and
|
|
# limitations under the License.
|
|
|
|
"""Module to handle errors and bailing out of an event/hook."""
|
|
|
|
import logging
|
|
from contextlib import (
|
|
contextmanager,
|
|
)
|
|
|
|
from ops.charm import (
|
|
CharmBase,
|
|
)
|
|
from ops.model import (
|
|
BlockedStatus,
|
|
MaintenanceStatus,
|
|
WaitingStatus,
|
|
)
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
class GuardExceptionError(Exception):
|
|
"""GuardException."""
|
|
|
|
pass
|
|
|
|
|
|
class BaseStatusExceptionError(Exception):
|
|
"""Charm is blocked."""
|
|
|
|
def __init__(self, msg):
|
|
self.msg = msg
|
|
super().__init__(self.msg)
|
|
|
|
|
|
class BlockedExceptionError(BaseStatusExceptionError):
|
|
"""Charm is blocked."""
|
|
|
|
pass
|
|
|
|
|
|
class MaintenanceExceptionError(BaseStatusExceptionError):
|
|
"""Charm is performing maintenance."""
|
|
|
|
pass
|
|
|
|
|
|
class WaitingExceptionError(BaseStatusExceptionError):
|
|
"""Charm is waiting."""
|
|
|
|
pass
|
|
|
|
|
|
@contextmanager
|
|
def guard(
|
|
charm: "CharmBase",
|
|
section: str,
|
|
handle_exception: bool = True,
|
|
log_traceback: bool = True,
|
|
**__,
|
|
) -> None:
|
|
"""Context manager to handle errors and bailing out of an event/hook.
|
|
|
|
The nature of Juju is that all the information may not be available to run
|
|
a set of actions. This context manager allows a section of code to be
|
|
'guarded' so that it can be bailed at any time.
|
|
|
|
It also handles errors which can be interpreted as a Block rather than the
|
|
charm going into error.
|
|
|
|
:param charm: the charm class (so that status can be set)
|
|
:param section: the name of the section (for debugging/info purposes)
|
|
:handle_exception: whether to handle the exception to a BlockedStatus()
|
|
:log_traceback: whether to log the traceback for debugging purposes.
|
|
:raises: Exception if handle_exception is False
|
|
"""
|
|
logger.info("Entering guarded section: '%s'", section)
|
|
try:
|
|
yield
|
|
logging.info("Completed guarded section fully: '%s'", section)
|
|
except GuardExceptionError as e:
|
|
logger.info(
|
|
"Guarded Section: Early exit from '%s' due to '%s'.",
|
|
section,
|
|
str(e),
|
|
)
|
|
except BlockedExceptionError as e:
|
|
logger.warning(
|
|
"Charm is blocked in section '%s' due to '%s'", section, str(e)
|
|
)
|
|
charm.status.set(BlockedStatus(e.msg))
|
|
except WaitingExceptionError as e:
|
|
logger.warning(
|
|
"Charm is waiting in section '%s' due to '%s'", section, str(e)
|
|
)
|
|
charm.status.set(WaitingStatus(e.msg))
|
|
except MaintenanceExceptionError as e:
|
|
logger.warning(
|
|
"Charm performing maintenance in section '%s' due to '%s'",
|
|
section,
|
|
str(e),
|
|
)
|
|
charm.status.set(MaintenanceStatus(e.msg))
|
|
except Exception as e:
|
|
# something else went wrong
|
|
if handle_exception:
|
|
logging.error(
|
|
"Exception raised in section '%s': %s", section, str(e)
|
|
)
|
|
if log_traceback:
|
|
import traceback
|
|
|
|
logging.error(traceback.format_exc())
|
|
charm.status.set(
|
|
BlockedStatus(
|
|
"Error in charm (see logs): {}".format(str(e))
|
|
)
|
|
)
|
|
return
|
|
raise
|