As of January 1, 2020 this library no longer supports Python 2 on the latest released version. Library versions released prior to that date will continue to be available. For more information please visit Python 2 support on Google Cloud.

Source code for google.cloud.client

# Copyright 2015 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.

"""Base classes for client used to interact with Google Cloud APIs."""

import io
import json
import os
from pickle import PicklingError

import six

import google.api_core.client_options
import google.api_core.exceptions
import google.auth
from google.auth import environment_vars
import google.auth.credentials
import google.auth.transport.requests
from google.cloud._helpers import _determine_default_project
from google.oauth2 import service_account


_GOOGLE_AUTH_CREDENTIALS_HELP = (
    "This library only supports credentials from google-auth-library-python. "
    "See https://google-auth.readthedocs.io/en/latest/ "
    "for help on authentication with this library."
)

# Default timeout for auth requests.
_CREDENTIALS_REFRESH_TIMEOUT = 300


class _ClientFactoryMixin(object):
    """Mixin to allow factories that create credentials.

    .. note::

        This class is virtual.
    """

    _SET_PROJECT = False

    @classmethod
    def from_service_account_json(cls, json_credentials_path, *args, **kwargs):
        """Factory to retrieve JSON credentials while creating client.

        :type json_credentials_path: str
        :param json_credentials_path: The path to a private key file (this file
                                      was given to you when you created the
                                      service account). This file must contain
                                      a JSON object with a private key and
                                      other credentials information (downloaded
                                      from the Google APIs console).

        :type args: tuple
        :param args: Remaining positional arguments to pass to constructor.

        :param kwargs: Remaining keyword arguments to pass to constructor.

        :rtype: :class:`_ClientFactoryMixin`
        :returns: The client created with the retrieved JSON credentials.
        :raises TypeError: if there is a conflict with the kwargs
                 and the credentials created by the factory.
        """
        if "credentials" in kwargs:
            raise TypeError("credentials must not be in keyword arguments")
        with io.open(json_credentials_path, "r", encoding="utf-8") as json_fi:
            credentials_info = json.load(json_fi)
        credentials = service_account.Credentials.from_service_account_info(
            credentials_info
        )
        if cls._SET_PROJECT:
            if "project" not in kwargs:
                kwargs["project"] = credentials_info.get("project_id")

        kwargs["credentials"] = credentials
        return cls(*args, **kwargs)


class Client(_ClientFactoryMixin):
    """Client to bundle configuration needed for API requests.

    Stores ``credentials`` and an HTTP object so that subclasses
    can pass them along to a connection class.

    If no value is passed in for ``_http``, a :class:`requests.Session` object
    will be created and authorized with the ``credentials``. If not, the
    ``credentials`` and ``_http`` need not be related.

    Callers and subclasses may seek to use the private key from
    ``credentials`` to sign data.

    Args:
        credentials (google.auth.credentials.Credentials):
            (Optional) The OAuth2 Credentials to use for this client. If not
            passed (and if no ``_http`` object is passed), falls back to the
            default inferred from the environment.
        client_options (google.api_core.client_options.ClientOptions):
            (Optional) Custom options for the client.
        _http (requests.Session):
            (Optional) HTTP object to make requests. Can be any object that
            defines ``request()`` with the same interface as
            :meth:`requests.Session.request`. If not passed, an ``_http``
            object is created that is bound to the ``credentials`` for the
            current object.
            This parameter should be considered private, and could change in
            the future.

    Raises:
        google.auth.exceptions.DefaultCredentialsError:
            Raised if ``credentials`` is not specified and the library fails
            to acquire default credentials.
    """

    SCOPE = None
    """The scopes required for authenticating with a service.

    Needs to be set by subclasses.
    """

    def __init__(self, credentials=None, _http=None, client_options=None):
        if isinstance(client_options, dict):
            client_options = google.api_core.client_options.from_dict(client_options)
        if client_options is None:
            client_options = google.api_core.client_options.ClientOptions()

        if credentials and client_options.credentials_file:
            raise google.api_core.exceptions.DuplicateCredentialArgs(
                "'credentials' and 'client_options.credentials_file' are mutually exclusive.")

        if credentials and not isinstance(credentials, google.auth.credentials.Credentials):
            raise ValueError(_GOOGLE_AUTH_CREDENTIALS_HELP)

        scopes = client_options.scopes or self.SCOPE

        # if no http is provided, credentials must exist
        if not _http and credentials is None:
            if client_options.credentials_file:
                credentials, _ = google.auth.load_credentials_from_file(
                    client_options.credentials_file, scopes=scopes)
            else:
                credentials, _ = google.auth.default(scopes=scopes)

        self._credentials = google.auth.credentials.with_scopes_if_required(
            credentials, scopes=scopes)

        if client_options.quota_project_id:
            self._credentials = self._credentials.with_quota_project(client_options.quota_project_id)

        self._http_internal = _http
        self._client_cert_source = client_options.client_cert_source

[docs] def __getstate__(self): """Explicitly state that clients are not pickleable.""" raise PicklingError( "\n".join( [ "Pickling client objects is explicitly not supported.", "Clients have non-trivial state that is local and unpickleable.", ] ) )
@property def _http(self): """Getter for object used for HTTP transport. :rtype: :class:`~requests.Session` :returns: An HTTP object. """ if self._http_internal is None: self._http_internal = google.auth.transport.requests.AuthorizedSession( self._credentials, refresh_timeout=_CREDENTIALS_REFRESH_TIMEOUT, ) self._http_internal.configure_mtls_channel(self._client_cert_source) return self._http_internal class _ClientProjectMixin(object): """Mixin to allow setting the project on the client. :type project: str :param project: (Optional) the project which the client acts on behalf of. If not passed, falls back to the default inferred from the environment. :type credentials: :class:`google.auth.credentials.Credentials` :param credentials: (Optional) credentials used to discover a project, if not passed. :raises: :class:`EnvironmentError` if the project is neither passed in nor set on the credentials or in the environment. :class:`ValueError` if the project value is invalid. """ def __init__(self, project=None, credentials=None): # This test duplicates the one from `google.auth.default`, but earlier, # for backward compatibility: we want the environment variable to # override any project set on the credentials. See: # https://github.com/googleapis/python-cloud-core/issues/27 if project is None: project = os.getenv( environment_vars.PROJECT, os.getenv(environment_vars.LEGACY_PROJECT), ) # Project set on explicit credentials overrides discovery from # SDK / GAE / GCE. if project is None and credentials is not None: project = getattr(credentials, "project_id", None) if project is None: project = self._determine_default(project) if project is None: raise EnvironmentError( "Project was not passed and could not be " "determined from the environment." ) if isinstance(project, six.binary_type): project = project.decode("utf-8") if not isinstance(project, six.string_types): raise ValueError("Project must be a string.") self.project = project @staticmethod def _determine_default(project): """Helper: use default project detection.""" return _determine_default_project(project) class ClientWithProject(Client, _ClientProjectMixin): """Client that also stores a project. :type project: str :param project: the project which the client acts on behalf of. If not passed falls back to the default inferred from the environment. :type credentials: :class:`~google.auth.credentials.Credentials` :param credentials: (Optional) The OAuth2 Credentials to use for this client. If not passed (and if no ``_http`` object is passed), falls back to the default inferred from the environment. :type _http: :class:`~requests.Session` :param _http: (Optional) HTTP object to make requests. Can be any object that defines ``request()`` with the same interface as :meth:`~requests.Session.request`. If not passed, an ``_http`` object is created that is bound to the ``credentials`` for the current object. This parameter should be considered private, and could change in the future. :raises: :class:`ValueError` if the project is neither passed in nor set in the environment. """ _SET_PROJECT = True # Used by from_service_account_json() def __init__(self, project=None, credentials=None, client_options=None, _http=None): _ClientProjectMixin.__init__(self, project=project, credentials=credentials) Client.__init__(self, credentials=credentials, client_options=client_options, _http=_http)