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.
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.
** 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.
Plugins are discovered by enumerating the entry points found under openstack.cli.extension and initializing the specified client module.
[entry_points]
openstack.cli.extension =
oscplugin = oscplugin.client
The client module must define the following top-level variables:
The client module must implement the following interface functions:
OSC enumerates the plugin commands from the entry points in the usual manner defined for the API version:
openstack.oscplugin.v1 =
plugin_list = oscplugin.v1.plugin:ListPlugin
plugin_show = oscplugin.v1.plugin:ShowPlugin
Note that OSC defines the group name as openstack. so the version should not contain the leading ‘v’ character.
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='<oscplugin-api-version>',
help='OSC Plugin API version, default=' +
DEFAULT_API_VERSION +
' (Env: OS_OSCPLUGIN_API_VERSION)')
return parser
OSC provides the following interfaces that may be used to implement the plugin commands:
# 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:
# OSC unit test interfaces available to plugins:
from openstackclient.tests import fakes
from openstackclient.tests import utils
...
OSC must be included in requirements.txt or test-requirements.txt for the plugin project. Update requirements.txt if the plugin project considers the CLI a required feature. Update test-requirements.txt if the plugin project can be installed as a library with the CLI being an optional feature (available when OSC is also installed).
python-openstackclient>=X.Y.Z # Apache-2.0
Creating the initial plugin described above is the first step. There are a few more steps needed to fully integrate the client with openstackclient.