barbican/barbican/common/quota.py

204 lines
7.5 KiB
Python

# Copyright (c) 2015 Cisco Systems
#
# 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.
from barbican.common import config
from barbican.common import exception
from barbican.common import hrefs
from barbican.common import resources as res
from barbican.model import repositories as repo
# All negative values will be treated as unlimited
UNLIMITED_VALUE = -1
DISABLED_VALUE = 0
CONF = config.CONF
class QuotaDriver(object):
"""Driver to enforce quotas and obtain quota information."""
def __init__(self):
self.repo = repo.get_project_quotas_repository()
def _get_resources(self):
"""List of resources that can be constrained by a quota"""
return ['secrets', 'orders', 'containers', 'consumers', 'cas']
def _get_defaults(self):
"""Return list of default quotas"""
quotas = {
'secrets': CONF.quotas.quota_secrets,
'orders': CONF.quotas.quota_orders,
'containers': CONF.quotas.quota_containers,
'consumers': CONF.quotas.quota_consumers,
'cas': CONF.quotas.quota_cas
}
return quotas
def _extract_project_quotas(self, project_quotas_model):
"""Convert project quotas model to Python dict
:param project_quotas_model: Model containing quota information
:return: Python dict containing quota information
"""
resp_quotas = {}
for resource in self._get_resources():
resp_quotas[resource] = getattr(project_quotas_model, resource)
return resp_quotas
def _compute_effective_quotas(self, configured_quotas):
"""Merge configured and default quota information
When a quota value is not set, use the default value
:param configured_quotas: configured quota values
:return: effective quotas
"""
default_quotas = self._get_defaults()
resp_quotas = dict(configured_quotas)
for resource, quota in resp_quotas.items():
if quota is None:
resp_quotas[resource] = default_quotas[resource]
return resp_quotas
def get_effective_quotas(self, external_project_id):
"""Collect and return the effective quotas for a project
:param external_project_id: external ID of current project
:return: dict with effective quotas
"""
try:
retrieved_project_quotas = self.repo.get_by_external_project_id(
external_project_id)
except exception.NotFound:
resp_quotas = self._get_defaults()
else:
resp_quotas = self._compute_effective_quotas(
self._extract_project_quotas(retrieved_project_quotas))
return resp_quotas
def is_unlimited_value(self, v):
"""A helper method to check for unlimited value."""
return v <= UNLIMITED_VALUE
def is_disabled_value(self, v):
"""A helper method to check for disabled value."""
return v == DISABLED_VALUE
def set_project_quotas(self, external_project_id, parsed_project_quotas):
"""Create a new database entry, or update existing one
:param external_project_id: ID of project whose quotas are to be set
:param parsed_project_quotas: quota values to save in database
:return: None
"""
project = res.get_or_create_project(external_project_id)
self.repo.create_or_update_by_project_id(project.id,
parsed_project_quotas)
# commit to DB to avoid async issues if the enforcer is called from
# another thread
repo.commit()
def get_project_quotas(self, external_project_id):
"""Retrieve configured quota information from database
:param external_project_id: ID of project for whose values are wanted
:return: the values
"""
try:
retrieved_project_quotas = self.repo.get_by_external_project_id(
external_project_id)
except exception.NotFound:
return None
resp_quotas = self._extract_project_quotas(retrieved_project_quotas)
resp = {'project_quotas': resp_quotas}
return resp
def get_project_quotas_list(self, offset_arg=None, limit_arg=None):
"""Return a dict and list of all configured quota information
:return: a dict and list of a page of quota config info
"""
retrieved_project_quotas, offset, limit, total =\
self.repo.get_by_create_date(offset_arg=offset_arg,
limit_arg=limit_arg,
suppress_exception=True)
resp_quotas = []
for quotas in retrieved_project_quotas:
list_item = {'project_id': quotas.project.external_id,
'project_quotas':
self._extract_project_quotas(quotas)}
resp_quotas.append(list_item)
resp = {'project_quotas': resp_quotas}
resp_overall = hrefs.add_nav_hrefs(
'project_quotas', offset, limit, total, resp)
resp_overall.update({'total': total})
return resp_overall
def delete_project_quotas(self, external_project_id):
"""Remove configured quota information from database
:param external_project_id: ID of project whose quotas will be deleted
:raises NotFound: if project has no configured values
:return: None
"""
self.repo.delete_by_external_project_id(external_project_id)
def get_quotas(self, external_project_id):
"""Get the effective quotas for a project
Effective quotas are based on both configured and default values
:param external_project_id: ID of project for which to get quotas
:return: dict of effective quota values
"""
resp_quotas = self.get_effective_quotas(external_project_id)
resp = {'quotas': resp_quotas}
return resp
class QuotaEnforcer(object):
"""Checks quotas limits and current resource usage levels"""
def __init__(self, resource_type, resource_repo):
self.quota_driver = QuotaDriver()
self.resource_type = resource_type
self.resource_repo = resource_repo
def enforce(self, project):
"""Enforce the quota limit for the resource
:param project: the project object corresponding to the sender
:raises QuotaReached: exception raised if quota forbids request
:return: None
"""
quotas = self.quota_driver.get_effective_quotas(project.external_id)
quota = quotas[self.resource_type]
reached = False
count = 0
if self.quota_driver.is_unlimited_value(quota):
pass
elif self.quota_driver.is_disabled_value(quota):
reached = True
else:
count = self.resource_repo.get_count(project.id)
if count >= quota:
reached = True
if reached:
raise exception.QuotaReached(
external_project_id=project.external_id,
resource_type=self.resource_type,
quota=quota)