blazar/blazar/policy.py
Jason Anderson ed238925f9
Use built-in oslo context de/serialization
The oslo context library has built-in mechanisms to deserialize a
context object from a set of headers; Blazar's built in extension of the
context class was ignoring several possibly-important pieces of
information, notably the Keystone domain name.

To fix, this removes much of the custom logic in the BlazarContext and
keeps only the two important bits:

1. A stack of contexts is maintained to allow for nested operations w/
   different sets of credentials
2. The service_catalog is preserved. It's unclear if this is really
   needed long-term, but some code still relies on it. Also unclear why
   the oslo context doesn't include this when parsing headers.

Support for multiple domains is included as part of this changeset.
Before, it was assumed that all users (admins and project users) were
part of the default domain.

Closes-Bug: #1881162
Change-Id: I75fcd97cf7a53d17c909620fcf41a8b5a3699dfa
2021-12-02 11:52:12 -06:00

123 lines
3.8 KiB
Python

# Copyright (c) 2013 Bull.
#
# 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.
"""Policy Engine For Blazar."""
import functools
from oslo_config import cfg
from oslo_log import log as logging
from oslo_policy import opts
from oslo_policy import policy
from blazar import context
from blazar import exceptions
from blazar import policies
CONF = cfg.CONF
LOG = logging.getLogger(__name__)
# TODO(gmann): Remove setting the default value of config policy_file
# once oslo_policy change the default value to 'policy.yaml'.
# https://github.com/openstack/oslo.policy/blob/a626ad12fe5a3abd49d70e3e5b95589d279ab578/oslo_policy/opts.py#L49
DEFAULT_POLICY_FILE = 'policy.yaml'
opts.set_defaults(CONF, DEFAULT_POLICY_FILE)
_ENFORCER = None
def reset():
global _ENFORCER
if _ENFORCER:
_ENFORCER.clear()
_ENFORCER = None
def init():
global _ENFORCER
if not _ENFORCER:
LOG.debug("Enforcer not present, recreating at init stage.")
_ENFORCER = policy.Enforcer(CONF)
_ENFORCER.register_defaults(policies.list_rules())
def set_rules(data, default_rule=None):
default_rule = default_rule or CONF.policy_default_rule
if not _ENFORCER:
LOG.debug("Enforcer not present, recreating at rules stage.")
init()
if default_rule:
_ENFORCER.default_rule = default_rule
_ENFORCER.set_rules(policy.Rules.load(data, default_rule))
def enforce(context, action, target, do_raise=True):
"""Verifies that the action is valid on the target in this context.
:param context: blazar context
:param action: string representing the action to be checked
this should be colon separated for clarity.
i.e. ``compute:create_instance``,
``compute:attach_volume``,
``volume:attach_volume``
:param target: dictionary representing the object of the action
for object creation this should be a dictionary representing the
location of the object e.g. ``{'project_id': context.project_id}``
:param do_raise: if True (the default), raises PolicyNotAuthorized;
if False, returns False
:raises blazar.exceptions.PolicyNotAuthorized: if verification fails
and do_raise is True.
:return: returns a non-False value (not necessarily "True") if
authorized, and the exact value False if not authorized and
do_raise is False.
"""
init()
credentials = context.to_policy_values()
# Add the exceptions arguments if asked to do a raise
extra = {}
if do_raise:
extra.update(exc=exceptions.PolicyNotAuthorized, action=action)
return _ENFORCER.enforce(action, target, credentials, do_raise=do_raise,
**extra)
def authorize(extension, action=None, api='blazar', ctx=None,
target=None):
def decorator(func):
@functools.wraps(func)
def wrapped(self, *args, **kwargs):
cur_ctx = ctx or context.current()
tgt = target or {'project_id': cur_ctx.project_id,
'user_id': cur_ctx.user_id}
if action is None:
act = '%s:%s' % (api, extension)
else:
act = '%s:%s:%s' % (api, extension, action)
enforce(cur_ctx, act, tgt)
return func(self, *args, **kwargs)
return wrapped
return decorator