def load_from_conf_options(conf, group, **kwargs):
"""Load a plugin from an oslo_config CONF object.
Each plugin will register their own required options and so there is no
standard list and the plugin should be consulted.
The base options should have been registered with register_conf_options
before this function is called.
:param conf: A conf object.
:type conf: oslo_config.cfg.ConfigOpts
:param string group: The group name that options should be read from.
:returns: An authentication Plugin or None if a name is not provided
:rtype: :py:class:`keystonauth.auth.BaseAuthPlugin`
:raises keystonauth.exceptions.NoMatchingPlugin: if a plugin cannot be
created.
"""
# NOTE(jamielennox): plugins are allowed to specify a 'section' which is
# the group that auth options should be taken from. If not present they
# come from the same as the base options were registered in.
if conf[group].auth_section:
group = conf[group].auth_section
name = conf[group].auth_plugin
if not name:
return None
plugin_class = base.get_plugin_class(name)
plugin_class.register_conf_options(conf, group)
return plugin_class.load_from_conf_options(conf, group, **kwargs)
def get_plugin_options(name):
"""Get the oslo_config options for a specific plugin.
This will be the list of config options that is registered and loaded by
the specified plugin.
:returns: A list of oslo_config options.
"""
return base.get_plugin_class(name).get_options()
def register_argparse_arguments(parser, argv, default=None):
"""Register CLI options needed to create a plugin.
The function inspects the provided arguments so that it can also register
the options required for that specific plugin if available.
:param argparse.ArgumentParser: the parser to attach argparse options to.
:param list argv: the arguments provided to the appliation.
:param str/class default: a default plugin name or a plugin object to use
if one isn't specified by the CLI. default: None.
:returns: The plugin class that will be loaded or None if not provided.
:rtype: :py:class:`keystonauth.auth.BaseAuthPlugin`
:raises keystonauth.exceptions.NoMatchingPlugin: if a plugin cannot be
created.
"""
in_parser = argparse.ArgumentParser(add_help=False)
env_plugin = os.environ.get('OS_AUTH_PLUGIN', default)
for p in (in_parser, parser):
p.add_argument('--os-auth-plugin',
metavar='<name>',
default=env_plugin,
help='The auth plugin to load')
options, _args = in_parser.parse_known_args(argv)
if not options.os_auth_plugin:
return None
if isinstance(options.os_auth_plugin, type):
msg = 'Default Authentication options'
plugin = options.os_auth_plugin
else:
msg = 'Options specific to the %s plugin.' % options.os_auth_plugin
plugin = base.get_plugin_class(options.os_auth_plugin)
group = parser.add_argument_group('Authentication Options', msg)
plugin.register_argparse_arguments(group)
return plugin
def load_from_argparse_arguments(namespace, **kwargs):
"""Retrieve the created plugin from the completed argparse results.
Loads and creates the auth plugin from the information parsed from the
command line by argparse.
:param Namespace namespace: The result from CLI parsing.
:returns: An auth plugin, or None if a name is not provided.
:rtype: :py:class:`keystonauth.auth.BaseAuthPlugin`
:raises keystonauth.exceptions.NoMatchingPlugin: if a plugin cannot be
created.
"""
if not namespace.os_auth_plugin:
return None
if isinstance(namespace.os_auth_plugin, type):
plugin = namespace.os_auth_plugin
else:
plugin = base.get_plugin_class(namespace.os_auth_plugin)
return plugin.load_from_argparse_arguments(namespace, **kwargs)
