keystoneauth/keystoneauth1/loading/cli.py
Morgan Fainberg 335a8cdf03 Remove use of positional decorator
The positional decorator results in poorly maintainable code in
a misguided effort to emulate python3's key-word-arg only notation
and functionality. This patch removes keysteonauth's dependance
on the positional decorator.

Change-Id: I20106345747860365cd0203ba1b33a2900e045b9
2017-08-07 16:37:07 -07:00

103 lines
3.7 KiB
Python

# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import argparse
import os
from keystoneauth1.loading import base
__all__ = ('register_argparse_arguments',
'load_from_argparse_arguments')
def _register_plugin_argparse_arguments(parser, plugin):
for opt in plugin.get_options():
parser.add_argument(*opt.argparse_args,
default=opt.argparse_default,
metavar=opt.metavar,
help=opt.help,
dest='os_%s' % opt.dest)
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 parser: the parser to attach argparse options to.
:type parser: argparse.ArgumentParser
: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: :class:`keystoneauth1.plugin.BaseAuthPlugin`
:raises keystoneauth1.exceptions.auth_plugins.NoMatchingPlugin:
if a plugin cannot be created.
"""
in_parser = argparse.ArgumentParser(add_help=False)
env_plugin = os.environ.get('OS_AUTH_TYPE',
os.environ.get('OS_AUTH_PLUGIN', default))
for p in (in_parser, parser):
p.add_argument('--os-auth-type',
'--os-auth-plugin',
metavar='<name>',
default=env_plugin,
help='Authentication type to use')
options, _args = in_parser.parse_known_args(argv)
if not options.os_auth_type:
return None
if isinstance(options.os_auth_type, base.BaseLoader):
msg = 'Default Authentication options'
plugin = options.os_auth_type
else:
msg = 'Options specific to the %s plugin.' % options.os_auth_type
plugin = base.get_plugin_loader(options.os_auth_type)
group = parser.add_argument_group('Authentication Options', msg)
_register_plugin_argparse_arguments(group, plugin)
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: :class:`keystoneauth1.plugin.BaseAuthPlugin`
:raises keystoneauth1.exceptions.auth_plugins.NoMatchingPlugin:
if a plugin cannot be created.
"""
if not namespace.os_auth_type:
return None
if isinstance(namespace.os_auth_type, type):
plugin = namespace.os_auth_type
else:
plugin = base.get_plugin_loader(namespace.os_auth_type)
def _getter(opt):
return getattr(namespace, 'os_%s' % opt.dest)
return plugin.load_from_options_getter(_getter, **kwargs)