vmware-nsx/quantum/quota.py
Yong Sheng Gong 67f88c2a4b Add quota features into quantum.
Blueprint quantum-api-quotas

We support quota check for creating network, subnet and port.
Change-Id: I943335816308767c7eba084d80b969fcb2e5a8fb
2012-07-20 09:40:35 +08:00

263 lines
9.1 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2011 OpenStack LLC
#
# 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.
"""Quotas for instances, volumes, and floating ips."""
import logging
from quantum.common import exceptions
from quantum.openstack.common import cfg
from quantum.openstack.common import importutils
LOG = logging.getLogger(__name__)
quota_opts = [
cfg.IntOpt('quota_network',
default=10,
help='number of networks allowed per tenant, -1 for unlimited'),
cfg.IntOpt('quota_subnet',
default=10,
help='number of subnets allowed per tenant, -1 for unlimited'),
cfg.IntOpt('quota_port',
default=50,
help='number of ports allowed per tenant, -1 for unlimited'),
cfg.StrOpt('quota_driver',
default='quantum.quota.ConfDriver',
help='default driver to use for quota checks'),
]
# Register the configuration options
cfg.CONF.register_opts(quota_opts, 'QUOTAS')
class ConfDriver(object):
"""
Driver to perform necessary checks to enforce quotas and obtain
quota information. The default driver utilizes the default values
in quantum.conf.
"""
def _get_quotas(self, context, resources, keys):
"""
A helper method which retrieves the quotas for the specific
resources identified by keys, and which apply to the current
context.
:param context: The request context, for access checks.
:param resources: A dictionary of the registered resources.
:param keys: A list of the desired quotas to retrieve.
"""
# Filter resources
desired = set(keys)
sub_resources = dict((k, v) for k, v in resources.items()
if k in desired)
# Make sure we accounted for all of them...
if len(keys) != len(sub_resources):
unknown = desired - set(sub_resources.keys())
raise exceptions.QuotaResourceUnknown(unknown=sorted(unknown))
quotas = {}
for resource in sub_resources.values():
quotas[resource.name] = resource.default
return quotas
def limit_check(self, context, resources, values):
"""Check simple quota limits.
For limits--those quotas for which there is no usage
synchronization function--this method checks that a set of
proposed values are permitted by the limit restriction.
This method will raise a QuotaResourceUnknown exception if a
given resource is unknown or if it is not a simple limit
resource.
If any of the proposed values is over the defined quota, an
OverQuota exception will be raised with the sorted list of the
resources which are too high. Otherwise, the method returns
nothing.
:param context: The request context, for access checks.
:param resources: A dictionary of the registered resources.
:param values: A dictionary of the values to check against the
quota.
"""
# Ensure no value is less than zero
unders = [key for key, val in values.items() if val < 0]
if unders:
raise exceptions.InvalidQuotaValue(unders=sorted(unders))
# Get the applicable quotas
quotas = self._get_quotas(context, resources, values.keys())
# Check the quotas and construct a list of the resources that
# would be put over limit by the desired values
overs = [key for key, val in values.items()
if quotas[key] >= 0 and quotas[key] < val]
if overs:
raise exceptions.OverQuota(overs=sorted(overs), quotas=quotas,
usages={})
class BaseResource(object):
"""Describe a single resource for quota checking."""
def __init__(self, name, flag=None):
"""
Initializes a Resource.
:param name: The name of the resource, i.e., "instances".
:param flag: The name of the flag or configuration option
which specifies the default value of the quota
for this resource.
"""
self.name = name
self.flag = flag
@property
def default(self):
"""Return the default value of the quota."""
return cfg.CONF.QUOTAS[self.flag] if self.flag else -1
class CountableResource(BaseResource):
"""Describe a resource where the counts are determined by a function.
"""
def __init__(self, name, count, flag=None):
"""Initializes a CountableResource.
Countable resources are those resources which directly
correspond to objects in the database, i.e., netowk, subnet,
etc.,. A CountableResource must be constructed with a counting
function, which will be called to determine the current counts
of the resource.
The counting function will be passed the context, along with
the extra positional and keyword arguments that are passed to
Quota.count(). It should return an integer specifying the
count.
:param name: The name of the resource, i.e., "instances".
:param count: A callable which returns the count of the
resource. The arguments passed are as described
above.
:param flag: The name of the flag or configuration option
which specifies the default value of the quota
for this resource.
"""
super(CountableResource, self).__init__(name, flag=flag)
self.count = count
class QuotaEngine(object):
"""Represent the set of recognized quotas."""
def __init__(self, quota_driver_class=None):
"""Initialize a Quota object."""
if not quota_driver_class:
quota_driver_class = cfg.CONF.QUOTAS.quota_driver
if isinstance(quota_driver_class, basestring):
quota_driver_class = importutils.import_object(quota_driver_class)
self._resources = {}
self._driver = quota_driver_class
def __contains__(self, resource):
return resource in self._resources
def register_resource(self, resource):
"""Register a resource."""
self._resources[resource.name] = resource
def register_resources(self, resources):
"""Register a list of resources."""
for resource in resources:
self.register_resource(resource)
def count(self, context, resource, *args, **kwargs):
"""Count a resource.
For countable resources, invokes the count() function and
returns its result. Arguments following the context and
resource are passed directly to the count function declared by
the resource.
:param context: The request context, for access checks.
:param resource: The name of the resource, as a string.
"""
# Get the resource
res = self._resources.get(resource)
if not res or not hasattr(res, 'count'):
raise exceptions.QuotaResourceUnknown(unknown=[resource])
return res.count(context, *args, **kwargs)
def limit_check(self, context, **values):
"""Check simple quota limits.
For limits--those quotas for which there is no usage
synchronization function--this method checks that a set of
proposed values are permitted by the limit restriction. The
values to check are given as keyword arguments, where the key
identifies the specific quota limit to check, and the value is
the proposed value.
This method will raise a QuotaResourceUnknown exception if a
given resource is unknown or if it is not a simple limit
resource.
If any of the proposed values is over the defined quota, an
OverQuota exception will be raised with the sorted list of the
resources which are too high. Otherwise, the method returns
nothing.
:param context: The request context, for access checks.
"""
return self._driver.limit_check(context, self._resources, values)
@property
def resources(self):
return sorted(self._resources.keys())
QUOTAS = QuotaEngine()
def _count_resource(context, plugin, resources, tenant_id):
obj_getter = getattr(plugin, "get_%s" % resources)
obj_list = obj_getter(context, filters={'tenant_id': [tenant_id]})
return len(obj_list) if obj_list else 0
resources = [
CountableResource('network', _count_resource, 'quota_network'),
CountableResource('subnet', _count_resource, 'quota_subnet'),
CountableResource('port', _count_resource, 'quota_port'),
]
QUOTAS.register_resources(resources)