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OpenStack Study: quota.py**** CubicPower OpenStack Study ****
# vim: tabstop=4 shiftwidth=4 softtabstop=4 # Copyright 2011 OpenStack Foundation # # 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 sys from oslo.config import cfg import webob from neutron.common import exceptions from neutron.common import legacy from neutron.openstack.common import importutils from neutron.openstack.common import log as logging LOG = logging.getLogger(__name__) QUOTA_DB_MODULE = 'neutron.db.quota_db' QUOTA_DB_DRIVER = 'neutron.db.quota_db.DbQuotaDriver' QUOTA_CONF_DRIVER = 'neutron.quota.ConfDriver' quota_opts = [ cfg.ListOpt('quota_items', default=['network', 'subnet', 'port'], help=_('Resource name(s) that are supported in quota ' 'features')), cfg.IntOpt('default_quota', default=-1, help=_('Default number of resource allowed per tenant. ' 'A negative value means unlimited.')), cfg.IntOpt('quota_network', default=10, help=_('Number of networks allowed per tenant.' 'A negative value means unlimited.')), cfg.IntOpt('quota_subnet', default=10, help=_('Number of subnets allowed per tenant, ' 'A negative value means unlimited.')), cfg.IntOpt('quota_port', default=50, help=_('Number of ports allowed per tenant. ' 'A negative value means unlimited.')), cfg.StrOpt('quota_driver', default=QUOTA_DB_DRIVER, help=_('Default driver to use for quota checks')), ] # Register the configuration options cfg.CONF.register_opts(quota_opts, 'QUOTAS') legacy.override_config(cfg.CONF, [('QUOTAS', 'quota_driver', 'neutron.quota')])
**** CubicPower OpenStack Study **** class ConfDriver(object): """Configuration driver. Driver to perform necessary checks to enforce quotas and obtain quota information. The
**** CubicPower OpenStack Study **** def _get_quotas(self, context, resources, keys): """Get quotas. 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
**** CubicPower OpenStack Study **** def limit_check(self, context, tenant_id, 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 tennant_id: The tenant_id to check quota. :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={}) @staticmethod
**** CubicPower OpenStack Study **** def get_tenant_quotas(context, resources, tenant_id): quotas = {} sub_resources = dict((k, v) for k, v in resources.items()) for resource in sub_resources.values(): quotas[resource.name] = resource.default return quotas @staticmethod
**** CubicPower OpenStack Study **** def get_all_quotas(context, resources): return [] @staticmethod
**** CubicPower OpenStack Study **** def delete_tenant_quota(context, tenant_id): msg = _('Access to this resource was denied.') raise webob.exc.HTTPForbidden(msg) @staticmethod
**** CubicPower OpenStack Study **** def update_quota_limit(context, tenant_id, resource, limit): msg = _('Access to this resource was denied.') raise webob.exc.HTTPForbidden(msg)
**** CubicPower OpenStack Study **** class BaseResource(object): """Describe a single resource for quota checking."""
**** CubicPower OpenStack Study **** def __init__(self, name, flag): """Initializes a resource. :param name: The name of the resource, i.e., "instances". :param flag: The name of the flag or configuration option """ self.name = name self.flag = flag @property
**** CubicPower OpenStack Study **** def default(self): """Return the default value of the quota.""" return getattr(cfg.CONF.QUOTAS, self.flag, cfg.CONF.QUOTAS.default_quota)
**** CubicPower OpenStack Study **** class CountableResource(BaseResource): """Describe a resource where the counts are determined by a function."""
**** CubicPower OpenStack Study **** 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
**** CubicPower OpenStack Study **** class QuotaEngine(object): """Represent the set of recognized quotas."""
**** CubicPower OpenStack Study **** def __init__(self, quota_driver_class=None): """Initialize a Quota object.""" self._resources = {} self._driver = None self._driver_class = quota_driver_class
**** CubicPower OpenStack Study **** def get_driver(self): if self._driver is None: _driver_class = (self._driver_class or cfg.CONF.QUOTAS.quota_driver) if (_driver_class == QUOTA_DB_DRIVER and QUOTA_DB_MODULE not in sys.modules): # If quotas table is not loaded, force config quota driver. _driver_class = QUOTA_CONF_DRIVER LOG.info(_("ConfDriver is used as quota_driver because the " "loaded plugin does not support 'quotas' table.")) if isinstance(_driver_class, basestring): _driver_class = importutils.import_object(_driver_class) self._driver = _driver_class LOG.info(_('Loaded quota_driver: %s.'), _driver_class) return self._driver
**** CubicPower OpenStack Study **** def __contains__(self, resource): return resource in self._resources
**** CubicPower OpenStack Study **** def register_resource(self, resource): """Register a resource.""" if resource.name in self._resources: LOG.warn(_('%s is already registered.'), resource.name) return self._resources[resource.name] = resource
**** CubicPower OpenStack Study **** def register_resource_by_name(self, resourcename): """Register a resource by name.""" resource = CountableResource(resourcename, _count_resource, 'quota_' + resourcename) self.register_resource(resource)
**** CubicPower OpenStack Study **** def register_resources(self, resources): """Register a list of resources.""" for resource in resources: self.register_resource(resource)
**** CubicPower OpenStack Study **** 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)
**** CubicPower OpenStack Study **** def limit_check(self, context, tenant_id, **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.get_driver().limit_check(context, tenant_id, self._resources, values) @property
**** CubicPower OpenStack Study **** def resources(self): return self._resources QUOTAS = QuotaEngine() def _count_resource(context, plugin, resources, tenant_id): count_getter_name = "get_%s_count" % resources # Some plugins support a count method for particular resources, # using a DB's optimized counting features. We try to use that one # if present. Otherwise just use regular getter to retrieve all objects # and count in python, allowing older plugins to still be supported try: obj_count_getter = getattr(plugin, count_getter_name) return obj_count_getter(context, filters={'tenant_id': [tenant_id]}) except (NotImplementedError, AttributeError): 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 def register_resources_from_config(): resources = [] for resource_item in cfg.CONF.QUOTAS.quota_items: resources.append(CountableResource(resource_item, _count_resource, 'quota_' + resource_item)) QUOTAS.register_resources(resources) register_resources_from_config()
**** CubicPower OpenStack Study **** def _count_resource(context, plugin, resources, tenant_id): count_getter_name = "get_%s_count" % resources # Some plugins support a count method for particular resources, # using a DB's optimized counting features. We try to use that one # if present. Otherwise just use regular getter to retrieve all objects # and count in python, allowing older plugins to still be supported try: obj_count_getter = getattr(plugin, count_getter_name) return obj_count_getter(context, filters={'tenant_id': [tenant_id]}) except (NotImplementedError, AttributeError): 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
**** CubicPower OpenStack Study **** def register_resources_from_config(): resources = [] for resource_item in cfg.CONF.QUOTAS.quota_items: resources.append(CountableResource(resource_item, _count_resource, 'quota_' + resource_item)) QUOTAS.register_resources(resources) register_resources_from_config()
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