keystoneauth/keystoneauth1/loading/opts.py
Jamie Lennox f21def7061 Use positional library instead of our own copy
The positional library was spun directly out of what keystoneauth1 was
using so this is a fairly trivial change.

Change-Id: I7931ed1547d2a05e2d248bc3240a576dc68a0a40
2016-01-25 09:31:48 +11:00

147 lines
5.2 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 itertools
import os
from positional import positional
try:
from oslo_config import cfg
except ImportError:
cfg = None
__all__ = ('Opt',)
class Opt(object):
"""An option required by an authentication plugin.
Opts provide a means for authentication plugins that are going to be
dynamically loaded to specify the parameters that are to be passed to the
plugin on initialization.
The Opt specifies information about the way the plugin parameter is to be
represented in different loading mechanisms.
When defining an Opt with a - the - should be present in the name
parameter. This will automatically be converted to an _ when passing to the
plugin initialization. For example, you should specify::
Opt('user-domain-id')
which will pass the value as `user_domain_id` to the plugin's
initialization.
:param str name: The name of the option.
:param callable type: The type of the option. This is a callable which is
passed the raw option that was loaded (often a string) and is required
to return the parameter in the type expected by __init__.
:param str help: The help text that is shown along with the option.
:param bool secret: If the parameter is secret it should not be printed or
logged in debug output.
:param str dest: the name of the argument that will be passed to __init__.
This allows you to have a different name in loading than is used by the
__init__ function. Defaults to the the value of name.
:param opt: A list of other options that are deprecated in favour of this
one. This ensures the old options are still registered.
:type opt: list(Opt)
:param default: A default value that can be used if one is not provided.
:param str metavar: The <metavar> that should be printed in CLI help text.
:param bool required: If the option is required to load the plugin. If a
required option is not present loading should fail.
"""
@positional()
def __init__(self,
name,
type=str,
help=None,
secret=False,
dest=None,
deprecated=None,
default=None,
metavar=None,
required=False):
if not callable(type):
raise TypeError('type must be callable')
if dest is None:
dest = name.replace('-', '_')
self.name = name
self.type = type
self.help = help
self.secret = secret
self.required = required
self.dest = dest
self.deprecated = [] if deprecated is None else deprecated
self.default = default
self.metavar = metavar
# These are for oslo.config compat
self.deprecated_opts = self.deprecated
self.deprecated_for_removal = []
self.sample_default = None
self.group = None
def __repr__(self):
return '<Opt: %s>' % self.name
def _to_oslo_opt(self):
if not cfg:
raise ImportError("oslo.config is not an automatic dependency of "
"keystoneauth. If you wish to use oslo.config "
"you need to import it into your application's "
"requirements file. ")
deprecated_opts = [cfg.DeprecatedOpt(o.name) for o in self.deprecated]
return cfg.Opt(name=self.name,
type=self.type,
help=self.help,
secret=self.secret,
required=self.required,
dest=self.dest,
deprecated_opts=deprecated_opts,
metavar=self.metavar)
def __eq__(self, other):
return (type(self) == type(other) and
self.name == other.name and
self.type == other.type and
self.help == other.help and
self.secret == other.secret and
self.required == other.required and
self.dest == other.dest and
self.deprecated == other.deprecated and
self.default == other.default and
self.metavar == other.metavar)
@property
def _all_opts(self):
return itertools.chain([self], self.deprecated)
@property
def argparse_args(self):
return ['--os-%s' % o.name for o in self._all_opts]
@property
def argparse_default(self):
# select the first ENV that is not false-y or return None
for o in self._all_opts:
v = os.environ.get('OS_%s' % o.name.replace('-', '_').upper())
if v:
return v
return self.default