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Diffstat (limited to 'google/auth/_default_async.py')
| -rw-r--r-- | google/auth/_default_async.py | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/google/auth/_default_async.py b/google/auth/_default_async.py new file mode 100644 index 0000000..fb277c5 --- /dev/null +++ b/google/auth/_default_async.py @@ -0,0 +1,281 @@ +# Copyright 2020 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. + +"""Application default credentials. + +Implements application default credentials and project ID detection. +""" + +import io +import json +import os + +import six + +from google.auth import _default +from google.auth import environment_vars +from google.auth import exceptions + + +def load_credentials_from_file(filename, scopes=None, quota_project_id=None): + """Loads Google credentials from a file. + + The credentials file must be a service account key or stored authorized + user credentials. + + Args: + filename (str): The full path to the credentials file. + scopes (Optional[Sequence[str]]): The list of scopes for the credentials. If + specified, the credentials will automatically be scoped if + necessary + quota_project_id (Optional[str]): The project ID used for + quota and billing. + + Returns: + Tuple[google.auth.credentials.Credentials, Optional[str]]: Loaded + credentials and the project ID. Authorized user credentials do not + have the project ID information. + + Raises: + google.auth.exceptions.DefaultCredentialsError: if the file is in the + wrong format or is missing. + """ + if not os.path.exists(filename): + raise exceptions.DefaultCredentialsError( + "File {} was not found.".format(filename) + ) + + with io.open(filename, "r") as file_obj: + try: + info = json.load(file_obj) + except ValueError as caught_exc: + new_exc = exceptions.DefaultCredentialsError( + "File {} is not a valid json file.".format(filename), caught_exc + ) + six.raise_from(new_exc, caught_exc) + + # The type key should indicate that the file is either a service account + # credentials file or an authorized user credentials file. + credential_type = info.get("type") + + if credential_type == _default._AUTHORIZED_USER_TYPE: + from google.oauth2 import _credentials_async as credentials + + try: + credentials = credentials.Credentials.from_authorized_user_info( + info, scopes=scopes + ) + except ValueError as caught_exc: + msg = "Failed to load authorized user credentials from {}".format(filename) + new_exc = exceptions.DefaultCredentialsError(msg, caught_exc) + six.raise_from(new_exc, caught_exc) + if quota_project_id: + credentials = credentials.with_quota_project(quota_project_id) + if not credentials.quota_project_id: + _default._warn_about_problematic_credentials(credentials) + return credentials, None + + elif credential_type == _default._SERVICE_ACCOUNT_TYPE: + from google.oauth2 import _service_account_async as service_account + + try: + credentials = service_account.Credentials.from_service_account_info( + info, scopes=scopes + ).with_quota_project(quota_project_id) + except ValueError as caught_exc: + msg = "Failed to load service account credentials from {}".format(filename) + new_exc = exceptions.DefaultCredentialsError(msg, caught_exc) + six.raise_from(new_exc, caught_exc) + return credentials, info.get("project_id") + + else: + raise exceptions.DefaultCredentialsError( + "The file {file} does not have a valid type. " + "Type is {type}, expected one of {valid_types}.".format( + file=filename, type=credential_type, valid_types=_default._VALID_TYPES + ) + ) + + +def _get_gcloud_sdk_credentials(quota_project_id=None): + """Gets the credentials and project ID from the Cloud SDK.""" + from google.auth import _cloud_sdk + + # Check if application default credentials exist. + credentials_filename = _cloud_sdk.get_application_default_credentials_path() + + if not os.path.isfile(credentials_filename): + return None, None + + credentials, project_id = load_credentials_from_file( + credentials_filename, quota_project_id=quota_project_id + ) + + if not project_id: + project_id = _cloud_sdk.get_project_id() + + return credentials, project_id + + +def _get_explicit_environ_credentials(quota_project_id=None): + """Gets credentials from the GOOGLE_APPLICATION_CREDENTIALS environment + variable.""" + from google.auth import _cloud_sdk + + cloud_sdk_adc_path = _cloud_sdk.get_application_default_credentials_path() + explicit_file = os.environ.get(environment_vars.CREDENTIALS) + + if explicit_file is not None and explicit_file == cloud_sdk_adc_path: + # Cloud sdk flow calls gcloud to fetch project id, so if the explicit + # file path is cloud sdk credentials path, then we should fall back + # to cloud sdk flow, otherwise project id cannot be obtained. + return _get_gcloud_sdk_credentials(quota_project_id=quota_project_id) + + if explicit_file is not None: + credentials, project_id = load_credentials_from_file( + os.environ[environment_vars.CREDENTIALS], quota_project_id=quota_project_id + ) + + return credentials, project_id + + else: + return None, None + + +def _get_gae_credentials(): + """Gets Google App Engine App Identity credentials and project ID.""" + # While this library is normally bundled with app_engine, there are + # some cases where it's not available, so we tolerate ImportError. + + return _default._get_gae_credentials() + + +def _get_gce_credentials(request=None): + """Gets credentials and project ID from the GCE Metadata Service.""" + # Ping requires a transport, but we want application default credentials + # to require no arguments. So, we'll use the _http_client transport which + # uses http.client. This is only acceptable because the metadata server + # doesn't do SSL and never requires proxies. + + # While this library is normally bundled with compute_engine, there are + # some cases where it's not available, so we tolerate ImportError. + + return _default._get_gce_credentials(request) + + +def default_async(scopes=None, request=None, quota_project_id=None): + """Gets the default credentials for the current environment. + + `Application Default Credentials`_ provides an easy way to obtain + credentials to call Google APIs for server-to-server or local applications. + This function acquires credentials from the environment in the following + order: + + 1. If the environment variable ``GOOGLE_APPLICATION_CREDENTIALS`` is set + to the path of a valid service account JSON private key file, then it is + loaded and returned. The project ID returned is the project ID defined + in the service account file if available (some older files do not + contain project ID information). + 2. If the `Google Cloud SDK`_ is installed and has application default + credentials set they are loaded and returned. + + To enable application default credentials with the Cloud SDK run:: + + gcloud auth application-default login + + If the Cloud SDK has an active project, the project ID is returned. The + active project can be set using:: + + gcloud config set project + + 3. If the application is running in the `App Engine standard environment`_ + (first generation) then the credentials and project ID from the + `App Identity Service`_ are used. + 4. If the application is running in `Compute Engine`_ or `Cloud Run`_ or + the `App Engine flexible environment`_ or the `App Engine standard + environment`_ (second generation) then the credentials and project ID + are obtained from the `Metadata Service`_. + 5. If no credentials are found, + :class:`~google.auth.exceptions.DefaultCredentialsError` will be raised. + + .. _Application Default Credentials: https://developers.google.com\ + /identity/protocols/application-default-credentials + .. _Google Cloud SDK: https://cloud.google.com/sdk + .. _App Engine standard environment: https://cloud.google.com/appengine + .. _App Identity Service: https://cloud.google.com/appengine/docs/python\ + /appidentity/ + .. _Compute Engine: https://cloud.google.com/compute + .. _App Engine flexible environment: https://cloud.google.com\ + /appengine/flexible + .. _Metadata Service: https://cloud.google.com/compute/docs\ + /storing-retrieving-metadata + .. _Cloud Run: https://cloud.google.com/run + + Example:: + + import google.auth + + credentials, project_id = google.auth.default() + + Args: + scopes (Sequence[str]): The list of scopes for the credentials. If + specified, the credentials will automatically be scoped if + necessary. + request (google.auth.transport.Request): An object used to make + HTTP requests. This is used to detect whether the application + is running on Compute Engine. If not specified, then it will + use the standard library http client to make requests. + quota_project_id (Optional[str]): The project ID used for + quota and billing. + Returns: + Tuple[~google.auth.credentials.Credentials, Optional[str]]: + the current environment's credentials and project ID. Project ID + may be None, which indicates that the Project ID could not be + ascertained from the environment. + + Raises: + ~google.auth.exceptions.DefaultCredentialsError: + If no credentials were found, or if the credentials found were + invalid. + """ + from google.auth._credentials_async import with_scopes_if_required + + explicit_project_id = os.environ.get( + environment_vars.PROJECT, os.environ.get(environment_vars.LEGACY_PROJECT) + ) + + checkers = ( + lambda: _get_explicit_environ_credentials(quota_project_id=quota_project_id), + lambda: _get_gcloud_sdk_credentials(quota_project_id=quota_project_id), + _get_gae_credentials, + lambda: _get_gce_credentials(request), + ) + + for checker in checkers: + credentials, project_id = checker() + if credentials is not None: + credentials = with_scopes_if_required( + credentials, scopes + ).with_quota_project(quota_project_id) + effective_project_id = explicit_project_id or project_id + if not effective_project_id: + _default._LOGGER.warning( + "No project ID could be determined. Consider running " + "`gcloud config set project` or setting the %s " + "environment variable", + environment_vars.PROJECT, + ) + return credentials, effective_project_id + + raise exceptions.DefaultCredentialsError(_default._HELP_MESSAGE) |