A common library that interfaces with VMware NSX.
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# Copyright 2020 VMware, Inc.
# All Rights Reserved
# 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.
from collections import namedtuple
import logging
import traceback
import six
from urllib3.exceptions import MaxRetryError
from urllib3.exceptions import ResponseError
from urllib3.util.retry import Retry
log = logging.getLogger(__name__)
RequestHistory = namedtuple(
"RequestHistory", ["method", "url", "error", "status", "redirect_location"]
class RetryDebug(Retry):
"""Class that adds debugging capabilities of Retry"""
def __init__(self, *args, **kw):
super(RetryDebug, self).__init__(*args, **kw)
def increment(self, method=None, url=None, response=None, error=None,
_pool=None, _stacktrace=None, ):
log.debug("Retry Increment %s", traceback.format_stack())
if self.total is False and error:
# Disabled, indicate to re-raise the error.
raise six.reraise(type(error), error, _stacktrace)
total = self.total
if total is not None:
total -= 1
connect = self.connect
read = self.read
redirect = self.redirect
status_count = self.status
cause = "unknown"
status = None
redirect_location = None
if error and self._is_connection_error(error):
# Connect retry?
if connect is False:
raise six.reraise(type(error), error, _stacktrace)
elif connect is not None:
connect -= 1
elif error and self._is_read_error(error):
# Read retry?
if read is False or not self._is_method_retryable(method):
raise six.reraise(type(error), error, _stacktrace)
elif read is not None:
read -= 1
elif response and response.get_redirect_location():
# Redirect retry?
if redirect is not None:
redirect -= 1
cause = "too many redirects"
redirect_location = response.get_redirect_location()
status = response.status
# Incrementing because of a server error like a 500 in
# status_forcelist and a the given method is in the whitelist
cause = ResponseError.GENERIC_ERROR
if response and response.status:
if status_count is not None:
status_count -= 1
cause = ResponseError.SPECIFIC_ERROR.format(
status = response.status
history = self.history + (
RequestHistory(method, url, error, status, redirect_location),
new_retry = self.new(
if new_retry.is_exhausted():
raise MaxRetryError(_pool, url, error or ResponseError(cause))
# log the cause for this retry
log.debug("Cause for retry: %s", cause)
# log the server response for this retry
log.debug("Response: %s", response)
log.debug("Incremented Retry for (url='%s'): %r", url, new_retry)
return new_retry