deb-mistral/mistral/db/utils.py
Lingxian Kong ce43812e90 Improve database object access checking
When Mistral is configured with 'auth_enable=True', we need to check
the resource accessbility when operating db resources (i.e. resource
RBAC). Such code logic will spread across the db layer. The patch move
these logic to on single place.

Change-Id: Ia8509986c18b63ef4b338f1dffb935f3fed5ad06
2017-03-15 07:26:52 +00:00

95 lines
3.1 KiB
Python

# Copyright 2016 - Nokia Networks
#
# 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 functools
from oslo_db import exception as db_exc
from oslo_log import log as logging
from oslo_service import loopingcall
from mistral import context
from mistral import exceptions as exc
from mistral.services import security
LOG = logging.getLogger(__name__)
@loopingcall.RetryDecorator(max_retry_count=100, inc_sleep_time=0,
exceptions=db_exc.DBDeadlock)
def _with_auth_context(auth_ctx, func, *args, **kw):
"""Runs the given function with the specified auth context.
:param auth_ctx: Authentication context.
:param func: Function to run with the specified auth context.
:param args: Function positional arguments.
:param kw: Function keywork arguments.
:return: Function result.
"""
old_auth_ctx = context.ctx() if context.has_ctx() else None
context.set_ctx(auth_ctx)
try:
return func(*args, **kw)
except db_exc.DBDeadlock as e:
LOG.exception(
"DB deadlock detected, operation will be retried: %s", func
)
raise e
finally:
context.set_ctx(old_auth_ctx)
def retry_on_deadlock(func):
"""Decorates the given function so that it retries on a DB deadlock.
:param func: Function to decorate.
:return: Decorated function.
"""
@functools.wraps(func)
def decorate(*args, **kw):
# We can't use RetryDecorator from oslo_service directly because
# it runs a decorated function in a different thread and hence
# the function doesn't have access to authentication context
# set as a thread local variable.
# The solution is to reuse RetryDecorator but explicitly set
# auth context in the new thread that RetryDecorator spawns.
# In order to do that we need an additional helper function.
auth_ctx = context.ctx() if context.has_ctx() else None
return _with_auth_context(auth_ctx, func, *args, **kw)
return decorate
def check_db_obj_access(db_obj):
"""Check accessbility to db object."""
ctx = context.ctx()
is_admin = ctx.is_admin
if not is_admin and db_obj.project_id != security.get_project_id():
raise exc.NotAllowedException(
"Can not access %s resource of other projects, ID: %s" %
(db_obj.__class__.__name__, db_obj.id)
)
if not is_admin and hasattr(db_obj, 'is_system') and db_obj.is_system:
raise exc.InvalidActionException(
"Can not modify a system %s resource, ID: %s" %
(db_obj.__class__.__name__, db_obj.id)
)