charm-neutron-api/hooks/charmhelpers/core/decorators.py
Alex Kavanagh 1bd71a1bed Updates for testing period for 20.01 release
Includes updates to charmhelpers/charms.openstack for cert_utils
and unit-get for the install hook error on Juju 2.9

* charm-helpers sync for classic charms
* rebuild for reactive charms
* ensure tox.ini is from release-tools
* ensure requirements.txt files are from release-tools
* On reactive charms:
  - ensure master branch for charms.openstack
  - ensure master branch for charm-helpers
* Remove mock for unit_get as it's no longer in c-h context module
* Remove sections from subordinate context due to c-h change.

Change-Id: Idd0e4963823ec2ed915795fb04913f11ba305a2e
2021-01-18 20:27:23 +00:00

94 lines
3.1 KiB
Python

# Copyright 2014-2015 Canonical Limited.
#
# 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.
#
# Copyright 2014 Canonical Ltd.
#
# Authors:
# Edward Hope-Morley <opentastic@gmail.com>
#
import time
from charmhelpers.core.hookenv import (
log,
INFO,
)
def retry_on_exception(num_retries, base_delay=0, exc_type=Exception):
"""If the decorated function raises exception exc_type, allow num_retries
retry attempts before raise the exception.
"""
def _retry_on_exception_inner_1(f):
def _retry_on_exception_inner_2(*args, **kwargs):
retries = num_retries
multiplier = 1
while True:
try:
return f(*args, **kwargs)
except exc_type:
if not retries:
raise
delay = base_delay * multiplier
multiplier += 1
log("Retrying '%s' %d more times (delay=%s)" %
(f.__name__, retries, delay), level=INFO)
retries -= 1
if delay:
time.sleep(delay)
return _retry_on_exception_inner_2
return _retry_on_exception_inner_1
def retry_on_predicate(num_retries, predicate_fun, base_delay=0):
"""Retry based on return value
The return value of the decorated function is passed to the given predicate_fun. If the
result of the predicate is False, retry the decorated function up to num_retries times
An exponential backoff up to base_delay^num_retries seconds can be introduced by setting
base_delay to a nonzero value. The default is to run with a zero (i.e. no) delay
:param num_retries: Max. number of retries to perform
:type num_retries: int
:param predicate_fun: Predicate function to determine if a retry is necessary
:type predicate_fun: callable
:param base_delay: Starting value in seconds for exponential delay, defaults to 0 (no delay)
:type base_delay: float
"""
def _retry_on_pred_inner_1(f):
def _retry_on_pred_inner_2(*args, **kwargs):
retries = num_retries
multiplier = 1
delay = base_delay
while True:
result = f(*args, **kwargs)
if predicate_fun(result) or retries <= 0:
return result
delay *= multiplier
multiplier += 1
log("Result {}, retrying '{}' {} more times (delay={})".format(
result, f.__name__, retries, delay), level=INFO)
retries -= 1
if delay:
time.sleep(delay)
return _retry_on_pred_inner_2
return _retry_on_pred_inner_1