neutron-lib/neutron_lib/context.py
Slawek Kaplonski 59c60b68fb Add policy module to neutron-lib
This module contains some constants and helper functions
which may be used in neutron, neutron staduim and neutron
3rd party projects.

Also already existing module _policy with policy engine
implementation for internal use of neutron-lib for moved to
the new neutron_lib.policy module and is now named
neutron_lib.policy._engine

Partially Implements: blueprint neutron-policy-in-code

Change-Id: Ie581788f78f6d83ae470981830df9e90a7cb72e8
2019-02-19 09:41:39 +01:00

193 lines
6.8 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.
"""Context: context for security/db session."""
import collections
import copy
import datetime
import warnings
from oslo_context import context as oslo_context
from oslo_db.sqlalchemy import enginefacade
from neutron_lib.db import api as db_api
from neutron_lib.policy import _engine as policy_engine
class ContextBase(oslo_context.RequestContext):
"""Security context and request information.
Represents the user taking a given action within the system.
"""
def __init__(self, user_id=None, tenant_id=None, is_admin=None,
timestamp=None, tenant_name=None, user_name=None,
is_advsvc=None, **kwargs):
# NOTE(jamielennox): We maintain this argument in order for tests that
# pass arguments positionally.
kwargs.setdefault('project_id', tenant_id)
# prefer project_name, as that's what's going to be set by
# keystone. Fall back to tenant_name if for some reason it's blank.
kwargs.setdefault('project_name', tenant_name)
super(ContextBase, self).__init__(
is_admin=is_admin, user_id=user_id, **kwargs)
self.user_name = user_name
if not timestamp:
timestamp = datetime.datetime.utcnow()
self.timestamp = timestamp
self.is_advsvc = is_advsvc
if self.is_advsvc is None:
self.is_advsvc = (self.is_admin or
policy_engine.check_is_advsvc(self))
if self.is_admin is None:
self.is_admin = policy_engine.check_is_admin(self)
@property
def tenant_id(self):
return self.project_id
@tenant_id.setter
def tenant_id(self, tenant_id):
self.project_id = tenant_id
@property
def tenant_name(self):
return self.project_name
@tenant_name.setter
def tenant_name(self, tenant_name):
self.project_name = tenant_name
def to_dict(self):
context = super(ContextBase, self).to_dict()
context.update({
'user_id': self.user_id,
'tenant_id': self.project_id,
'project_id': self.project_id,
'timestamp': str(self.timestamp),
'tenant_name': self.project_name,
'project_name': self.project_name,
'user_name': self.user_name,
})
return context
def to_policy_values(self):
values = super(ContextBase, self).to_policy_values()
values['tenant_id'] = self.project_id
values['is_admin'] = self.is_admin
# NOTE(jamielennox): These are almost certainly unused and non-standard
# but kept for backwards compatibility. Remove them in Pike
# (oslo.context from Ocata release already issues deprecation warnings
# for non-standard keys).
values['user'] = self.user_id
values['tenant'] = self.project_id
values['domain'] = self.domain_id
values['user_domain'] = self.user_domain_id
values['project_domain'] = self.project_domain_id
values['tenant_name'] = self.project_name
values['project_name'] = self.project_name
values['user_name'] = self.user_name
return values
@classmethod
def from_dict(cls, values):
return cls(user_id=values.get('user_id', values.get('user')),
tenant_id=values.get('tenant_id', values.get('project_id')),
is_admin=values.get('is_admin'),
roles=values.get('roles'),
timestamp=values.get('timestamp'),
request_id=values.get('request_id'),
tenant_name=values.get('tenant_name'),
user_name=values.get('user_name'),
auth_token=values.get('auth_token'))
def elevated(self):
"""Return a version of this context with admin flag set."""
context = copy.copy(self)
context.is_admin = True
if 'admin' not in [x.lower() for x in context.roles]:
context.roles = context.roles + ["admin"]
return context
@enginefacade.transaction_context_provider
class ContextBaseWithSession(ContextBase):
pass
_TransactionConstraint = collections.namedtuple(
'TransactionConstraint', ['if_revision_match', 'resource', 'resource_id'])
class Context(ContextBaseWithSession):
def __init__(self, *args, **kwargs):
super(Context, self).__init__(*args, **kwargs)
self._session = None
self._txn_constraint = None
@property
def session(self):
# TODO(akamyshnikova): checking for session attribute won't be needed
# when reader and writer will be used
if hasattr(super(Context, self), 'session'):
if self._session:
warnings.warn('context.session is used with and without '
'new enginefacade. Please update the code to '
'use new enginefacede consistently.',
DeprecationWarning)
return super(Context, self).session
if self._session is None:
self._session = db_api.get_writer_session()
return self._session
def set_transaction_constraint(self, resource, resource_id, rev_number):
"""Set a revision constraint to enforce before resource_id is changed.
:param resource: Collection name of resource (e.g. ports or networks)
:param resource_id: The primary key ID of the individual resource that
should have its revision number matched before
allowing the transaction to proceed.
:param rev_number: The revision_number that the resource should be at.
"""
self._txn_constraint = _TransactionConstraint(
if_revision_match=rev_number, resource=resource,
resource_id=resource_id)
def clear_transaction_constraint(self):
self._txn_constraint = None
def get_transaction_constraint(self):
return self._txn_constraint
def get_admin_context():
return Context(user_id=None,
tenant_id=None,
is_admin=True,
overwrite=False)
def get_admin_context_without_session():
return ContextBase(user_id=None,
tenant_id=None,
is_admin=True)