cue/cue/common/policy.py

104 lines
3.1 KiB
Python

# Copyright (c) 2011 OpenStack Foundation
# All Rights Reserved.
#
# 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 Cue."""
from oslo.config import cfg
from cue.common import exception
from cue.common.i18n import _ # noqa
from cue.common.i18n import _LI # noqa
from cue.openstack.common import log as logging
from cue.openstack.common import policy
LOG = logging.getLogger(__name__)
_ENFORCER = None
def reset():
global _ENFORCER
if _ENFORCER:
_ENFORCER.clear()
_ENFORCER = None
def set_rules(data, default_rule=None, overwrite=True):
default_rule = default_rule or cfg.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
msg = "Loading rules %s, default: %s, overwrite: %s"
LOG.debug(msg, data, default_rule, overwrite)
if isinstance(data, dict):
rules = dict((k, policy.parse_rule(v)) for k, v in data.items())
rules = policy.Rules(rules, default_rule)
else:
rules = policy.Rules.load_json(data, default_rule)
_ENFORCER.set_rules(rules, overwrite=overwrite)
def init(default_rule=None):
policy_file = cfg.CONF.find_file(cfg.CONF.policy_file)
if len(policy_file) == 0:
msg = 'Unable to determine appropriate policy json file'
raise exception.ConfigurationError(msg)
LOG.info(_LI('Using policy_file found at: %s') % policy_file)
with open(policy_file) as fh:
policy_string = fh.read()
rules = policy.Rules.load_json(policy_string, default_rule=default_rule)
global _ENFORCER
if not _ENFORCER:
LOG.debug("Enforcer is not present, recreating.")
_ENFORCER = policy.Enforcer()
_ENFORCER.set_rules(rules)
def check(rule, ctxt, target=None, do_raise=True, exc=exception.NotAuthorized):
#creds = ctxt.to_dict()
target = target or {}
try:
result = _ENFORCER.enforce(rule, target, ctxt, do_raise, exc)
except Exception:
result = False
raise
else:
return result
finally:
extra = {'policy': {'rule': rule, 'target': target}}
if result:
LOG.info(_("Policy check succeeded for rule '%(rule)s' "
"on target %(target)s") %
{'rule': rule, 'target': repr(target)}, extra=extra)
else:
LOG.info(_("Policy check failed for rule '%(rule)s' "
"on target %(target)s") %
{'rule': rule, 'target': repr(target)}, extra=extra)