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"""
This module is the requests implementation of Pipeline ABC
"""
from __future__ import absolute_import # we have a "requests" module that conflicts with "requests" on Py2.7
import logging
from typing import TYPE_CHECKING, List, Callable, Iterator, Any, Union, Dict, Optional # pylint: disable=unused-import
try:
from urlparse import urlparse # type: ignore
except ImportError:
from urllib.parse import urlparse
from azure.core.exceptions import TooManyRedirectsError
from ._base import HTTPPolicy, RequestHistory
_LOGGER = logging.getLogger(__name__)
class RedirectPolicyBase(object):
REDIRECT_STATUSES = frozenset([300, 301, 302, 303, 307, 308])
REDIRECT_HEADERS_BLACKLIST = frozenset(['Authorization'])
def __init__(self, **kwargs):
self.allow = kwargs.get('permit_redirects', True)
self.max_redirects = kwargs.get('redirect_max', 30)
remove_headers = set(kwargs.get('redirect_remove_headers', []))
self._remove_headers_on_redirect = remove_headers.union(self.REDIRECT_HEADERS_BLACKLIST)
redirect_status = set(kwargs.get('redirect_on_status_codes', []))
self._redirect_on_status_codes = redirect_status.union(self.REDIRECT_STATUSES)
super(RedirectPolicyBase, self).__init__()
@classmethod
def no_redirects(cls):
"""Disable redirects.
"""
return cls(permit_redirects=False)
def configure_redirects(self, options):
"""Configures the redirect settings.
:param options: Keyword arguments from context.
:return: A dict containing redirect settings and a history of redirects.
:rtype: dict
"""
return {
'allow': options.pop("permit_redirects", self.allow),
'redirects': options.pop("redirect_max", self.max_redirects),
'history': []
}
def get_redirect_location(self, response):
"""Checks for redirect status code and gets redirect location.
:param response: The PipelineResponse object
:type response: ~azure.core.pipeline.PipelineResponse
:return: Truthy redirect location string if we got a redirect status
code and valid location. ``None`` if redirect status and no
location. ``False`` if not a redirect status code.
"""
if response.http_response.status_code in [301, 302]:
if response.http_request.method in ['GET', 'HEAD', ]:
return response.http_response.headers.get('location')
return False
if response.http_response.status_code in self._redirect_on_status_codes:
return response.http_response.headers.get('location')
return False
def increment(self, settings, response, redirect_location):
"""Increment the redirect attempts for this request.
:param dict settings: The redirect settings
:param response: A pipeline response object.
:type response: ~azure.core.pipeline.PipelineResponse
:param str redirect_location: The redirected endpoint.
:return: Whether further redirect attempts are remaining.
False if exhausted; True if more redirect attempts available.
:rtype: bool
"""
# TODO: Revise some of the logic here.
settings['redirects'] -= 1
settings['history'].append(RequestHistory(response.http_request, http_response=response.http_response))
redirected = urlparse(redirect_location)
if not redirected.netloc:
base_url = urlparse(response.http_request.url)
response.http_request.url = "{}://{}/{}".format(
base_url.scheme,
base_url.netloc,
redirect_location.lstrip('/'))
else:
response.http_request.url = redirect_location
if response.http_response.status_code == 303:
response.http_request.method = 'GET'
for non_redirect_header in self._remove_headers_on_redirect:
response.http_request.headers.pop(non_redirect_header, None)
return settings['redirects'] >= 0
[docs]class RedirectPolicy(RedirectPolicyBase, HTTPPolicy):
"""A redirect policy.
A redirect policy in the pipeline can be configured directly or per operation.
:keyword bool permit_redirects: Whether the client allows redirects. Defaults to True.
:keyword int redirect_max: The maximum allowed redirects. Defaults to 30.
.. admonition:: Example:
.. literalinclude:: ../samples/test_example_sync.py
:start-after: [START redirect_policy]
:end-before: [END redirect_policy]
:language: python
:dedent: 4
:caption: Configuring a redirect policy.
"""
[docs] def send(self, request):
"""Sends the PipelineRequest object to the next policy.
Uses redirect settings to send request to redirect endpoint if necessary.
:param request: The PipelineRequest object
:type request: ~azure.core.pipeline.PipelineRequest
:return: Returns the PipelineResponse or raises error if maximum redirects exceeded.
:rtype: ~azure.core.pipeline.PipelineResponse
:raises: ~azure.core.exceptions.TooManyRedirectsError if maximum redirects exceeded.
"""
retryable = True
redirect_settings = self.configure_redirects(request.context.options)
while retryable:
response = self.next.send(request)
redirect_location = self.get_redirect_location(response)
if redirect_location and redirect_settings['allow']:
retryable = self.increment(redirect_settings, response, redirect_location)
request.http_request = response.http_request
continue
return response
raise TooManyRedirectsError(redirect_settings['history'])