======= Plugins ======= The OpenStackClient plugin system is designed so that the plugin need only be properly installed for OSC to find and use it. It utilizes the ``setuptools`` entry points mechanism to advertise to OSC the plugin module and supported commands. Adoption ======== OpenStackClient promises to provide first class support for the following OpenStack services: Compute, Identity, Image, Object Storage, Block Storage and Network (core objects). These services are considered essential to any OpenStack deployment. Other OpenStack services, such as Orchestration or Telemetry may create an OpenStackClient plugin. The source code will not be hosted by OpenStackClient. The following is a list of projects that are an OpenStackClient plugin. - aodhclient - gnocchiclient - python-barbicanclient - python-congressclient - python-designateclient - python-heatclient - python-ironicclient - python-ironic-inspector-client - python-mistralclient - python-muranoclient - python-neutronclient\*\*\* - python-saharaclient - python-searchlightclient - python-senlinclient - python-tripleoclient\*\* - python-troveclient - python-watcherclient - python-zaqarclient \*\* Note that some clients are not listed in global-requirements. \*\*\* Project contains advanced network services. The following is a list of projects that are not an OpenStackClient plugin. - python-magnumclient - python-ceilometerclient - python-solumclient Implementation ============== Client module ------------- Plugins are discovered by enumerating the entry points found under :py:mod:`openstack.cli.extension` and initializing the specified client module. .. code-block:: ini [entry_points] openstack.cli.extension = oscplugin = oscplugin.client The client module must define the following top-level variables: * ``API_NAME`` - A string containing the plugin API name; this is the name of the entry point declaring the plugin client module (``oscplugin = ...`` in the example above) and the group name for the plugin commands (``openstack.oscplugin.v1 =`` in the example below). OSC reserves the following API names: ``compute``, ``identity``, ``image``, ``network``, ``object_store`` and ``volume``. * ``API_VERSION_OPTION`` (optional) - If set, the name of the API version attribute; this must be a valid Python identifier and match the destination set in ``build_option_parser()``. * ``API_VERSIONS`` - A dict mapping a version string to the client class The client module must implement the following interface functions: * ``build_option_parser(parser)`` - Hook to add global options to the parser * ``make_client(instance)`` - Hook to create the client object OSC enumerates the plugin commands from the entry points in the usual manner defined for the API version: .. code-block:: ini openstack.oscplugin.v1 = plugin_list = oscplugin.v1.plugin:ListPlugin plugin_show = oscplugin.v1.plugin:ShowPlugin Note that OSC defines the group name as :py:mod:`openstack..v` so the version should not contain the leading 'v' character. .. code-block:: python from osc_lib import utils DEFAULT_API_VERSION = '1' # Required by the OSC plugin interface API_NAME = 'oscplugin' API_VERSION_OPTION = 'os_oscplugin_api_version' API_VERSIONS = { '1': 'oscplugin.v1.client.Client', } # Required by the OSC plugin interface def make_client(instance): """Returns a client to the ClientManager Called to instantiate the requested client version. instance has any available auth info that may be required to prepare the client. :param ClientManager instance: The ClientManager that owns the new client """ plugin_client = utils.get_client_class( API_NAME, instance._api_version[API_NAME], API_VERSIONS) client = plugin_client() return client # Required by the OSC plugin interface def build_option_parser(parser): """Hook to add global options Called from openstackclient.shell.OpenStackShell.__init__() after the builtin parser has been initialized. This is where a plugin can add global options such as an API version setting. :param argparse.ArgumentParser parser: The parser object that has been initialized by OpenStackShell. """ parser.add_argument( '--os-oscplugin-api-version', metavar='', help='OSC Plugin API version, default=' + DEFAULT_API_VERSION + ' (Env: OS_OSCPLUGIN_API_VERSION)') return parser Client usage of OSC interfaces ------------------------------ OSC provides the following interfaces that may be used to implement the plugin commands: .. code-block:: python # osc-lib interfaces available to plugins: from osc_lib.cli import parseractions from osc_lib.command import command from osc_lib import exceptions from osc_lib import logs from osc_lib import utils class DeleteMypluginobject(command.Command): """Delete mypluginobject""" ... def take_action(self, parsed_args): # Client manager interfaces are available to plugins. # This includes the OSC clients created. client_manager = self.app.client_manager ... return OSC provides the following interfaces that may be used to implement unit tests for the plugin commands: .. code-block:: python # OSC unit test interfaces available to plugins: from openstackclient.tests import fakes from openstackclient.tests import utils ... Requirements ------------ OSC should be included in the plugin's ``test-requirements.txt`` if the plugin can be installed as a library with the CLI being an optional feature (available when OSC is also installed). OSC should not appear in ``requirements.txt`` unless the plugin project wants OSC and all of its dependencies installed with it. This is specifically not a good idea for plugins that are also libraries installed with OpenStack services. .. code-block:: ini python-openstackclient>=X.Y.Z # Apache-2.0 Checklist for adding new OpenStack plugins ========================================== Creating the initial plugin described above is the first step. There are a few more steps needed to fully integrate the client with openstackclient. Add the command checker to your CI ---------------------------------- #. Modify the section of ``zuul/layout.yaml`` related to your repository to add ``osc-plugin-jobs`` to the list of job templates for your project. This job checks that to see if any new commands are: duplicated, missing entry points, or have overlap; across all openstackclient plugins. #. Update ``jenkins/scripts/check-osc-plugins.sh`` to include your new library to be installed from source. This is essential in running the previously mentioned check job. Simply add ``install_from_source python-fooclient`` to the block of code where all other clients are installed. Changes to python-openstackclient --------------------------------- #. In ``doc/source/plugins.rst``, update the `Adoption` section to reflect the status of the project. #. Update ``doc/source/commands.rst`` to include objects that are defined by fooclient's new plugin. #. Update ``doc/source/plugin-commands.rst`` to include the entry point defined in fooclient. We use `sphinxext`_ to automatically document commands that are used. #. Update ``test-requirements.txt`` to include fooclient. This is necessary to auto-document the commands in the previous step. .. _sphinxext: http://docs.openstack.org/developer/stevedore/sphinxext.html