# Copyright 2020 Google LLC
#
# 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.
"""Transport adapter for Async HTTP (aiohttp).
NOTE: This async support is experimental and marked internal. This surface may
change in minor releases.
"""
from __future__ import absolute_import
import asyncio
import functools
import aiohttp # type: ignore
import urllib3 # type: ignore
from google.auth import exceptions
from google.auth import transport
from google.auth.transport import requests
# Timeout can be re-defined depending on async requirement. Currently made 60s more than
# sync timeout.
_DEFAULT_TIMEOUT = 180 # in seconds
class _CombinedResponse(transport.Response):
"""
In order to more closely resemble the `requests` interface, where a raw
and deflated content could be accessed at once, this class lazily reads the
stream in `transport.Response` so both return forms can be used.
The gzip and deflate transfer-encodings are automatically decoded for you
because the default parameter for autodecompress into the ClientSession is set
to False, and therefore we add this class to act as a wrapper for a user to be
able to access both the raw and decoded response bodies - mirroring the sync
implementation.
"""
def __init__(self, response):
self._response = response
self._raw_content = None
def _is_compressed(self):
headers = self._response.headers
return "Content-Encoding" in headers and (
headers["Content-Encoding"] == "gzip"
or headers["Content-Encoding"] == "deflate"
)
@property
def status(self):
return self._response.status
@property
def headers(self):
return self._response.headers
@property
def data(self):
return self._response.content
async def raw_content(self):
if self._raw_content is None:
self._raw_content = await self._response.content.read()
return self._raw_content
async def content(self):
# Load raw_content if necessary
await self.raw_content()
if self._is_compressed():
decoder = urllib3.response.MultiDecoder(
self._response.headers["Content-Encoding"]
)
decompressed = decoder.decompress(self._raw_content)
return decompressed
return self._raw_content
class _Response(transport.Response):
"""
Requests transport response adapter.
Args:
response (requests.Response): The raw Requests response.
"""
def __init__(self, response):
self._response = response
@property
def status(self):
return self._response.status
@property
def headers(self):
return self._response.headers
@property
def data(self):
return self._response.content
[docs]
class Request(transport.Request):
"""Requests request adapter.
This class is used internally for making requests using asyncio transports
in a consistent way. If you use :class:`AuthorizedSession` you do not need
to construct or use this class directly.
This class can be useful if you want to manually refresh a
:class:`~google.auth.credentials.Credentials` instance::
import google.auth.transport.aiohttp_requests
request = google.auth.transport.aiohttp_requests.Request()
credentials.refresh(request)
Args:
session (aiohttp.ClientSession): An instance :class:`aiohttp.ClientSession` used
to make HTTP requests. If not specified, a session will be created.
.. automethod:: __call__
"""
def __init__(self, session=None):
# TODO: Use auto_decompress property for aiohttp 3.7+
if session is not None and session._auto_decompress:
raise exceptions.InvalidOperation(
"Client sessions with auto_decompress=True are not supported."
)
self.session = session
[docs]
async def __call__(
self,
url,
method="GET",
body=None,
headers=None,
timeout=_DEFAULT_TIMEOUT,
**kwargs,
):
"""
Make an HTTP request using aiohttp.
Args:
url (str): The URL to be requested.
method (Optional[str]):
The HTTP method to use for the request. Defaults to 'GET'.
body (Optional[bytes]):
The payload or body in HTTP request.
headers (Optional[Mapping[str, str]]):
Request headers.
timeout (Optional[int]): The number of seconds to wait for a
response from the server. If not specified or if None, the
requests default timeout will be used.
kwargs: Additional arguments passed through to the underlying
requests :meth:`requests.Session.request` method.
Returns:
google.auth.transport.Response: The HTTP response.
Raises:
google.auth.exceptions.TransportError: If any exception occurred.
"""
try:
if self.session is None: # pragma: NO COVER
self.session = aiohttp.ClientSession(
auto_decompress=False
) # pragma: NO COVER
requests._LOGGER.debug("Making request: %s %s", method, url)
response = await self.session.request(
method, url, data=body, headers=headers, timeout=timeout, **kwargs
)
return _CombinedResponse(response)
except aiohttp.ClientError as caught_exc:
new_exc = exceptions.TransportError(caught_exc)
raise new_exc from caught_exc
except asyncio.TimeoutError as caught_exc:
new_exc = exceptions.TransportError(caught_exc)
raise new_exc from caught_exc
[docs]
class AuthorizedSession(aiohttp.ClientSession):
"""This is an async implementation of the Authorized Session class. We utilize an
aiohttp transport instance, and the interface mirrors the google.auth.transport.requests
Authorized Session class, except for the change in the transport used in the async use case.
A Requests Session class with credentials.
This class is used to perform requests to API endpoints that require
authorization::
from google.auth.transport import aiohttp_requests
async with aiohttp_requests.AuthorizedSession(credentials) as authed_session:
response = await authed_session.request(
'GET', 'https://www.googleapis.com/storage/v1/b')
The underlying :meth:`request` implementation handles adding the
credentials' headers to the request and refreshing credentials as needed.
Args:
credentials (google.auth._credentials_async.Credentials):
The credentials to add to the request.
refresh_status_codes (Sequence[int]): Which HTTP status codes indicate
that credentials should be refreshed and the request should be
retried.
max_refresh_attempts (int): The maximum number of times to attempt to
refresh the credentials and retry the request.
refresh_timeout (Optional[int]): The timeout value in seconds for
credential refresh HTTP requests.
auth_request (google.auth.transport.aiohttp_requests.Request):
(Optional) An instance of
:class:`~google.auth.transport.aiohttp_requests.Request` used when
refreshing credentials. If not passed,
an instance of :class:`~google.auth.transport.aiohttp_requests.Request`
is created.
kwargs: Additional arguments passed through to the underlying
ClientSession :meth:`aiohttp.ClientSession` object.
"""
def __init__(
self,
credentials,
refresh_status_codes=transport.DEFAULT_REFRESH_STATUS_CODES,
max_refresh_attempts=transport.DEFAULT_MAX_REFRESH_ATTEMPTS,
refresh_timeout=None,
auth_request=None,
auto_decompress=False,
**kwargs,
):
super(AuthorizedSession, self).__init__(**kwargs)
self.credentials = credentials
self._refresh_status_codes = refresh_status_codes
self._max_refresh_attempts = max_refresh_attempts
self._refresh_timeout = refresh_timeout
self._is_mtls = False
self._auth_request = auth_request
self._auth_request_session = None
self._loop = asyncio.get_event_loop()
self._refresh_lock = asyncio.Lock()
self._auto_decompress = auto_decompress
[docs]
async def request(
self,
method,
url,
data=None,
headers=None,
max_allowed_time=None,
timeout=_DEFAULT_TIMEOUT,
auto_decompress=False,
**kwargs,
):
"""Implementation of Authorized Session aiohttp request.
Args:
method (str):
The http request method used (e.g. GET, PUT, DELETE)
url (str):
The url at which the http request is sent.
data (Optional[dict]): Dictionary, list of tuples, bytes, or file-like
object to send in the body of the Request.
headers (Optional[dict]): Dictionary of HTTP Headers to send with the
Request.
timeout (Optional[Union[float, aiohttp.ClientTimeout]]):
The amount of time in seconds to wait for the server response
with each individual request. Can also be passed as an
``aiohttp.ClientTimeout`` object.
max_allowed_time (Optional[float]):
If the method runs longer than this, a ``Timeout`` exception is
automatically raised. Unlike the ``timeout`` parameter, this
value applies to the total method execution time, even if
multiple requests are made under the hood.
Mind that it is not guaranteed that the timeout error is raised
at ``max_allowed_time``. It might take longer, for example, if
an underlying request takes a lot of time, but the request
itself does not timeout, e.g. if a large file is being
transmitted. The timout error will be raised after such
request completes.
"""
# Headers come in as bytes which isn't expected behavior, the resumable
# media libraries in some cases expect a str type for the header values,
# but sometimes the operations return these in bytes types.
if headers:
for key in headers.keys():
if type(headers[key]) is bytes:
headers[key] = headers[key].decode("utf-8")
async with aiohttp.ClientSession(
auto_decompress=self._auto_decompress
) as self._auth_request_session:
auth_request = Request(self._auth_request_session)
self._auth_request = auth_request
# Use a kwarg for this instead of an attribute to maintain
# thread-safety.
_credential_refresh_attempt = kwargs.pop("_credential_refresh_attempt", 0)
# Make a copy of the headers. They will be modified by the credentials
# and we want to pass the original headers if we recurse.
request_headers = headers.copy() if headers is not None else {}
# Do not apply the timeout unconditionally in order to not override the
# _auth_request's default timeout.
auth_request = (
self._auth_request
if timeout is None
else functools.partial(self._auth_request, timeout=timeout)
)
remaining_time = max_allowed_time
with requests.TimeoutGuard(remaining_time, asyncio.TimeoutError) as guard:
await self.credentials.before_request(
auth_request, method, url, request_headers
)
with requests.TimeoutGuard(remaining_time, asyncio.TimeoutError) as guard:
response = await super(AuthorizedSession, self).request(
method,
url,
data=data,
headers=request_headers,
timeout=timeout,
**kwargs,
)
remaining_time = guard.remaining_timeout
if (
response.status in self._refresh_status_codes
and _credential_refresh_attempt < self._max_refresh_attempts
):
requests._LOGGER.info(
"Refreshing credentials due to a %s response. Attempt %s/%s.",
response.status,
_credential_refresh_attempt + 1,
self._max_refresh_attempts,
)
# Do not apply the timeout unconditionally in order to not override the
# _auth_request's default timeout.
auth_request = (
self._auth_request
if timeout is None
else functools.partial(self._auth_request, timeout=timeout)
)
with requests.TimeoutGuard(
remaining_time, asyncio.TimeoutError
) as guard:
async with self._refresh_lock:
await self._loop.run_in_executor(
None, self.credentials.refresh, auth_request
)
remaining_time = guard.remaining_timeout
return await self.request(
method,
url,
data=data,
headers=headers,
max_allowed_time=remaining_time,
timeout=timeout,
_credential_refresh_attempt=_credential_refresh_attempt + 1,
**kwargs,
)
return response
