A Brief History
===============

*openstacksdk* started its life as three different libraries: *shade*,
*os-client-config* and *python-openstacksdk*.

*shade*
  *shade* started its life as some code inside of OpenStack Infra's `nodepool`_
  project, and as some code inside of the `Ansible OpenStack Modules`_.
  Ansible had a bunch of different OpenStack related modules, and there was a
  ton of duplicated code. Eventually, between refactoring that duplication into
  an internal library, and adding the logic and features that the OpenStack
  Infra team had developed to run client applications at scale, it turned out
  that we'd written nine-tenths of what we'd need to have a standalone library.

  Because of its background from nodepool, *shade* contained abstractions to
  work around deployment differences and is resource oriented rather than
  service oriented. This allows a user to think about Security Groups without
  having to know whether Security Groups are provided by Nova or Neutron on a
  given cloud. On the other hand, as an interface that provides an abstraction,
  it deviates from the published OpenStack REST API and adds its own opinions,
  which may not get in the way of more advanced users with specific needs.

*os-client-config*
  *os-client-config* was a library for collecting client configuration for
  using an OpenStack cloud in a consistent and comprehensive manner, which
  introduced the ``clouds.yaml`` file for expressing named cloud
  configurations.

*python-openstacksdk*
  *python-openstacksdk* was a library that exposed the OpenStack APIs to
  developers in a consistent and predictable manner.

After a while it became clear that there was value in both the high-level
layer that contains additional business logic and the lower-level SDK that
exposes services and their resources faithfully and consistently as Python
objects. Even with both of those layers, it is still beneficial at times to be
able to make direct REST calls and to do so with the same properly configured
`Session`_ from `python-requests`_. This led to the merge of the three
projects.

The original contents of the *shade* library have been moved into
``openstack.cloud`` and *os-client-config* has been moved in to
``openstack.config``.

.. _nodepool: https://docs.openstack.org/infra/nodepool/
.. _Ansible OpenStack Modules: http://docs.ansible.com/ansible/latest/list_of_cloud_modules.html#openstack
.. _Session: http://docs.python-requests.org/en/master/user/advanced/#session-objects
.. _python-requests: http://docs.python-requests.org/en/master/
