kuryr-kubernetes/kuryr_kubernetes/utils.py

80 lines
2.4 KiB
Python

# 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.
import random
import time
from oslo_config import cfg
from oslo_serialization import jsonutils
CONF = cfg.CONF
DEFAULT_TIMEOUT = 180
DEFAULT_INTERVAL = 3
def utf8_json_decoder(byte_data):
"""Deserializes the bytes into UTF-8 encoded JSON.
:param byte_data: The bytes to be converted into the UTF-8 encoded JSON.
:returns: The UTF-8 encoded JSON represented by Python dictionary format.
"""
return jsonutils.loads(byte_data.decode('utf8'))
def convert_netns(netns):
"""Convert /proc based netns path to Docker-friendly path.
When CONF.docker_mode is set this method will change /proc to
/CONF.netns_proc_dir. This allows netns manipulations to work when running
in Docker container on Kubernetes host.
:param netns: netns path to convert.
:return: Converted netns path.
"""
if CONF.cni_daemon.docker_mode:
return netns.replace('/proc', CONF.cni_daemon.netns_proc_dir)
else:
return netns
def exponential_sleep(deadline, attempt, interval=DEFAULT_INTERVAL):
"""Sleep for exponential duration.
This implements a variation of exponential backoff algorithm [1] and
ensures that there is a minimal time `interval` to sleep.
(expected backoff E(c) = interval * 2 ** c / 2).
[1] https://en.wikipedia.org/wiki/Exponential_backoff
:param deadline: sleep timeout duration in seconds.
:param attempt: attempt count of sleep function.
:param interval: minimal time interval to sleep
:return: the actual time that we've slept
"""
now = time.time()
seconds_left = deadline - now
if seconds_left <= 0:
return 0
interval = random.randint(1, 2 ** attempt - 1) * DEFAULT_INTERVAL
if interval > seconds_left:
interval = seconds_left
if interval < DEFAULT_INTERVAL:
interval = DEFAULT_INTERVAL
time.sleep(interval)
return interval