:mod:`airflow.contrib.hooks.gcp_api_base_hook`
==============================================

.. py:module:: airflow.contrib.hooks.gcp_api_base_hook







Module Contents
---------------






.. data:: _DEFAULT_SCOPES
   :annotation: = ['https://www.googleapis.com/auth/cloud-platform'] 

   









.. data:: _G_APP_CRED_ENV_VAR
   :annotation: = GOOGLE_APPLICATION_CREDENTIALS 

   









.. py:class:: GoogleCloudBaseHook(gcp_conn_id='google_cloud_default', delegate_to=None)

   Bases::class:`airflow.hooks.base_hook.BaseHook`

   

   A base hook for Google cloud-related hooks. Google cloud has a shared REST
   API client that is built in the same way no matter which service you use.
   This class helps construct and authorize the credentials needed to then
   call googleapiclient.discovery.build() to actually discover and build a client
   for a Google cloud service.

   The class also contains some miscellaneous helper functions.

   All hook derived from this base hook use the 'Google Cloud Platform' connection
   type. Three ways of authentication are supported:

   Default credentials: Only the 'Project Id' is required. You'll need to
   have set up default credentials, such as by the
   ``GOOGLE_APPLICATION_DEFAULT`` environment variable or from the metadata
   server on Google Compute Engine.

   JSON key file: Specify 'Project Id', 'Keyfile Path' and 'Scope'.

   Legacy P12 key files are not supported.

   JSON data provided in the UI: Specify 'Keyfile JSON'.


   

   

   .. py:class:: _Decorators

      Bases::class:`object`

      

      A private inner class for keeping all decorator methods.


      

      

      .. staticmethod:: provide_gcp_credential_file(func)

         
         Function decorator that provides a GOOGLE_APPLICATION_CREDENTIALS
         environment variable, pointing to file path of a JSON file of service
         account key.

         





   

   

   .. attribute:: project_id
      

      



   

   

   

   .. method:: _get_credentials(self)

      
      Returns the Credentials object for Google API

      



   

   .. method:: _get_access_token(self)

      
      Returns a valid access token from Google API Credentials

      



   

   .. method:: _authorize(self)

      
      Returns an authorized HTTP object to be used to build a Google cloud
      service hook connection.

      



   

   .. method:: _get_field(self, f, default=None)

      
      Fetches a field from extras, and returns it. This is some Airflow
      magic. The google_cloud_platform hook type adds custom UI elements
      to the hook page, which allow admins to specify service_account,
      key_path, etc. They get formatted as shown below.

      



   

   .. staticmethod:: catch_http_exception(func)

      
      Function decorator that intercepts HTTP Errors and raises AirflowException
      with more informative message.

      



   

   .. staticmethod:: fallback_to_default_project_id(func)

      
      Decorator that provides fallback for Google Cloud Platform project id. If
      the project is None it will be replaced with the project_id from the
      service account the Hook is authenticated with. Project id can be specified
      either via project_id kwarg or via first parameter in positional args.

      :param func: function to wrap
      :return: result of the function call

      



   

   .. method:: _get_project_id(self, project_id)

      
      In case project_id is None, overrides it with default project_id from
      the service account that is authorized.

      :param project_id: project id to
      :type project_id: str
      :return: the project_id specified or default project id if project_id is None