Replace custom blob gRPC API with ByteStream

client/third_party/google/auth/compute_engine/credentials.py

+# Copyright 2016 Google Inc.
+#
+# 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.
+
+"""Google Compute Engine credentials.
+
+This module provides authentication for application running on Google Compute
+Engine using the Compute Engine metadata server.
+
+"""
+
+from google.auth import credentials
+from google.auth import exceptions
+from google.auth.compute_engine import _metadata
+
+
+class Credentials(credentials.Scoped, credentials.Credentials):
+    """Compute Engine Credentials.
+
+    These credentials use the Google Compute Engine metadata server to obtain
+    OAuth 2.0 access tokens associated with the instance's service account.
+
+    For more information about Compute Engine authentication, including how
+    to configure scopes, see the `Compute Engine authentication
+    documentation`_.
+
+    .. note:: Compute Engine instances can be created with scopes and therefore
+        these credentials are considered to be 'scoped'. However, you can
+        not use :meth:`~google.auth.credentials.ScopedCredentials.with_scopes`
+        because it is not possible to change the scopes that the instance
+        has. Also note that
+        :meth:`~google.auth.credentials.ScopedCredentials.has_scopes` will not
+        work until the credentials have been refreshed.
+
+    .. _Compute Engine authentication documentation:
+        https://cloud.google.com/compute/docs/authentication#using
+    """
+
+    def __init__(self, service_account_email='default'):
+        """
+        Args:
+            service_account_email (str): The service account email to use, or
+                'default'. A Compute Engine instance may have multiple service
+                accounts.
+        """
+        super(Credentials, self).__init__()
+        self._service_account_email = service_account_email
+
+    def _retrieve_info(self, request):
+        """Retrieve information about the service account.
+
+        Updates the scopes and retrieves the full service account email.
+
+        Args:
+            request (google.auth.transport.Request): The object used to make
+                HTTP requests.
+        """
+        info = _metadata.get_service_account_info(
+            request,
+            service_account=self._service_account_email)
+
+        self._service_account_email = info['email']
+        self._scopes = info['scopes']
+
+    def refresh(self, request):
+        """Refresh the access token and scopes.
+
+        Args:
+            request (google.auth.transport.Request): The object used to make
+                HTTP requests.
+
+        Raises:
+            google.auth.exceptions.RefreshError: If the Compute Engine metadata
+                service can't be reached if if the instance has not
+                credentials.
+        """
+        try:
+            self._retrieve_info(request)
+            self.token, self.expiry = _metadata.get_service_account_token(
+                request,
+                service_account=self._service_account_email)
+        except exceptions.TransportError as exc:
+            raise exceptions.RefreshError(exc)
+
+    @property
+    def service_account_email(self):
+        """The service account email.
+
+        .. note: This is not guaranteed to be set until :meth`refresh` has been
+            called.
+        """
+        return self._service_account_email
+
+    @property
+    def requires_scopes(self):
+        """False: Compute Engine credentials can not be scoped."""
+        return False
+
+    def with_scopes(self, scopes):
+        """Unavailable, Compute Engine credentials can not be scoped.
+
+        Scopes can only be set at Compute Engine instance creation time.
+        See the `Compute Engine authentication documentation`_ for details on
+        how to configure instance scopes.
+
+        .. _Compute Engine authentication documentation:
+            https://cloud.google.com/compute/docs/authentication#using
+        """
+        raise NotImplementedError(
+            'Compute Engine credentials can not set scopes. Scopes must be '
+            'set when the Compute Engine instance is created.')