The nova.quota Module

Quotas for instances, and floating ips.

class AbsoluteResource(name, flag=None)

Bases: nova.quota.BaseResource

Describe a non-reservable resource.

class BaseResource(name, flag=None)

Bases: object

Describe a single resource for quota checking.

default

Return the default value of the quota.

quota(driver, context, **kwargs)

Given a driver and context, obtain the quota for this resource.

Parameters:

• driver – A quota driver.
• context – The request context.
• project_id – The project to obtain the quota value for. If not provided, it is taken from the context. If it is given as None, no project-specific quota will be searched for.
• quota_class – The quota class corresponding to the project, or for which the quota is to be looked up. If not provided, it is taken from the context. If it is given as None, no quota class-specific quota will be searched for. Note that the quota class defaults to the value in the context, which may not correspond to the project if project_id is not the same as the one in the context.

class CountableResource(name, count, flag=None)

Bases: nova.quota.AbsoluteResource

Describe a resource where the counts aren’t based solely on the project ID.

class DbQuotaDriver

Bases: object

Driver to perform necessary checks to enforce quotas and obtain quota information. The default driver utilizes the local database.

commit(context, reservations, project_id=None)

Commit reservations.

Parameters:

• context – The request context, for access checks.
• reservations – A list of the reservation UUIDs, as returned by the reserve() method.
• project_id – Specify the project_id if current context is admin and admin wants to impact on common user’s tenant.

destroy_all_by_project(context, project_id)

Destroy all quotas, usages, and reservations associated with a project.

Parameters:

• context – The request context, for access checks.
• project_id – The ID of the project being deleted.

expire(context)

Expire reservations.

Explores all currently existing reservations and rolls back any that have expired.

Parameters:context – The request context, for access checks.

get_by_class(context, quota_class, resource)

Get a specific quota by quota class.

get_by_project(context, project_id, resource)

Get a specific quota by project.

get_class_quotas(context, resources, quota_class, defaults=True)

Given a list of resources, retrieve the quotas for the given quota class.

Parameters:

• context – The request context, for access checks.
• resources – A dictionary of the registered resources.
• quota_class – The name of the quota class to return quotas for.
• defaults – If True, the default value will be reported if there is no specific value for the resource.

get_defaults(context, resources)

Given a list of resources, retrieve the default quotas.

Parameters:

• context – The request context, for access checks.
• resources – A dictionary of the registered resources.

get_project_quotas(context, resources, project_id, quota_class=None, defaults=True, usages=True)

Given a list of resources, retrieve the quotas for the given project.

Parameters:

• context – The request context, for access checks.
• resources – A dictionary of the registered resources.
• project_id – The ID of the project to return quotas for.
• quota_class – If project_id != context.project_id, the quota class cannot be determined. This parameter allows it to be specified. It will be ignored if project_id == context.project_id.
• defaults – If True, the quota class value (or the default value, if there is no value from the quota class) will be reported if there is no specific value for the resource.
• usages – If True, the current in_use and reserved counts will also be returned.

limit_check(context, resources, values, project_id=None)

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.

Parameters:

• context – The request context, for access checks.
• resources – A dictionary of the registered resources.
• values – A dictionary of the values to check against the quota.
• project_id – Specify the project_id if current context is admin and admin wants to impact on common user’s tenant.

reserve(context, resources, deltas, expire=None, project_id=None)

Check quotas and reserve resources.

For counting quotas–those quotas for which there is a usage synchronization function–this method checks quotas against current usage and the desired deltas.

This method will raise a QuotaResourceUnknown exception if a given resource is unknown or if it does not have a usage synchronization function.

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 a list of reservation UUIDs which were created.

Parameters:

• context – The request context, for access checks.
• resources – A dictionary of the registered resources.
• deltas – A dictionary of the proposed delta changes.
• expire – An optional parameter specifying an expiration time for the reservations. If it is a simple number, it is interpreted as a number of seconds and added to the current time; if it is a datetime.timedelta object, it will also be added to the current time. A datetime.datetime object will be interpreted as the absolute expiration time. If None is specified, the default expiration time set by –default-reservation-expire will be used (this value will be treated as a number of seconds).
• project_id – Specify the project_id if current context is admin and admin wants to impact on common user’s tenant.

rollback(context, reservations, project_id=None)

Roll back reservations.

Parameters:

• context – The request context, for access checks.
• reservations – A list of the reservation UUIDs, as returned by the reserve() method.
• project_id – Specify the project_id if current context is admin and admin wants to impact on common user’s tenant.

usage_reset(context, resources)

Reset the usage records for a particular user on a list of resources. This will force that user’s usage records to be refreshed the next time a reservation is made.

Note: this does not affect the currently outstanding reservations the user has; those reservations must be committed or rolled back (or expired).

Parameters:

• context – The request context, for access checks.
• resources – A list of the resource names for which the usage must be reset.

class NoopQuotaDriver

Bases: object

Driver that turns quotas calls into no-ops and pretends that quotas for all resources are unlimited. This can be used if you do not wish to have any quota checking. For instance, with nova compute cells, the parent cell should do quota checking, but the child cell should not.

commit(context, reservations, project_id=None)

Commit reservations.

Parameters:

• context – The request context, for access checks.
• reservations – A list of the reservation UUIDs, as returned by the reserve() method.
• project_id – Specify the project_id if current context is admin and admin wants to impact on common user’s tenant.

destroy_all_by_project(context, project_id)

Destroy all quotas, usages, and reservations associated with a project.

Parameters:

• context – The request context, for access checks.
• project_id – The ID of the project being deleted.

expire(context)

Expire reservations.

Explores all currently existing reservations and rolls back any that have expired.

Parameters:context – The request context, for access checks.

get_by_class(context, quota_class, resource)

Get a specific quota by quota class.

get_by_project(context, project_id, resource)

Get a specific quota by project.

get_class_quotas(context, resources, quota_class, defaults=True)

Given a list of resources, retrieve the quotas for the given quota class.

Parameters:

• context – The request context, for access checks.
• resources – A dictionary of the registered resources.
• quota_class – The name of the quota class to return quotas for.
• defaults – If True, the default value will be reported if there is no specific value for the resource.

get_defaults(context, resources)

Given a list of resources, retrieve the default quotas.

Parameters:

• context – The request context, for access checks.
• resources – A dictionary of the registered resources.

get_project_quotas(context, resources, project_id, quota_class=None, defaults=True, usages=True)

Given a list of resources, retrieve the quotas for the given project.

Parameters:

• context – The request context, for access checks.
• resources – A dictionary of the registered resources.
• project_id – The ID of the project to return quotas for.
• quota_class – If project_id != context.project_id, the quota class cannot be determined. This parameter allows it to be specified. It will be ignored if project_id == context.project_id.
• defaults – If True, the quota class value (or the default value, if there is no value from the quota class) will be reported if there is no specific value for the resource.
• usages – If True, the current in_use and reserved counts will also be returned.

limit_check(context, resources, values, project_id=None)

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.

Parameters:

• context – The request context, for access checks.
• resources – A dictionary of the registered resources.
• values – A dictionary of the values to check against the quota.
• project_id – Specify the project_id if current context is admin and admin wants to impact on common user’s tenant.

reserve(context, resources, deltas, expire=None, project_id=None)

Check quotas and reserve resources.

For counting quotas–those quotas for which there is a usage synchronization function–this method checks quotas against current usage and the desired deltas.

This method will raise a QuotaResourceUnknown exception if a given resource is unknown or if it does not have a usage synchronization function.

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 a list of reservation UUIDs which were created.

Parameters:

• context – The request context, for access checks.
• resources – A dictionary of the registered resources.
• deltas – A dictionary of the proposed delta changes.
• expire – An optional parameter specifying an expiration time for the reservations. If it is a simple number, it is interpreted as a number of seconds and added to the current time; if it is a datetime.timedelta object, it will also be added to the current time. A datetime.datetime object will be interpreted as the absolute expiration time. If None is specified, the default expiration time set by –default-reservation-expire will be used (this value will be treated as a number of seconds).
• project_id – Specify the project_id if current context is admin and admin wants to impact on common user’s tenant.

rollback(context, reservations, project_id=None)

Roll back reservations.

Parameters:

• context – The request context, for access checks.
• reservations – A list of the reservation UUIDs, as returned by the reserve() method.
• project_id – Specify the project_id if current context is admin and admin wants to impact on common user’s tenant.

usage_reset(context, resources)

Reset the usage records for a particular user on a list of resources. This will force that user’s usage records to be refreshed the next time a reservation is made.

Note: this does not affect the currently outstanding reservations the user has; those reservations must be committed or rolled back (or expired).

Parameters:

• context – The request context, for access checks.
• resources – A list of the resource names for which the usage must be reset.

class QuotaEngine(quota_driver_class=None)

Bases: object

Represent the set of recognized quotas.

commit(context, reservations, project_id=None)

Commit reservations.

Parameters:

• context – The request context, for access checks.
• reservations – A list of the reservation UUIDs, as returned by the reserve() method.
• project_id – Specify the project_id if current context is admin and admin wants to impact on common user’s tenant.

count(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.

Parameters:

• context – The request context, for access checks.
• resource – The name of the resource, as a string.

destroy_all_by_project(context, project_id)

Destroy all quotas, usages, and reservations associated with a project.

Parameters:

• context – The request context, for access checks.
• project_id – The ID of the project being deleted.

expire(context)

Expire reservations.

Explores all currently existing reservations and rolls back any that have expired.

Parameters:context – The request context, for access checks.

get_by_class(context, quota_class, resource)

Get a specific quota by quota class.

get_by_project(context, project_id, resource)

Get a specific quota by project.

get_class_quotas(context, quota_class, defaults=True)

Retrieve the quotas for the given quota class.

Parameters:

• context – The request context, for access checks.
• quota_class – The name of the quota class to return quotas for.
• defaults – If True, the default value will be reported if there is no specific value for the resource.

get_defaults(context)

Retrieve the default quotas.

Parameters:context – The request context, for access checks.

get_project_quotas(context, project_id, quota_class=None, defaults=True, usages=True)

Retrieve the quotas for the given project.

Parameters:

• context – The request context, for access checks.
• project_id – The ID of the project to return quotas for.
• quota_class – If project_id != context.project_id, the quota class cannot be determined. This parameter allows it to be specified.
• defaults – If True, the quota class value (or the default value, if there is no value from the quota class) will be reported if there is no specific value for the resource.
• usages – If True, the current in_use and reserved counts will also be returned.

limit_check(context, project_id=None, **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.

Parameters:

• context – The request context, for access checks.
• project_id – Specify the project_id if current context is admin and admin wants to impact on common user’s tenant.

register_resource(resource)

Register a resource.

register_resources(resources)

Register a list of resources.

reserve(context, expire=None, project_id=None, **deltas)

Check quotas and reserve resources.

For counting quotas–those quotas for which there is a usage synchronization function–this method checks quotas against current usage and the desired deltas. The deltas are given as keyword arguments, and current usage and other reservations are factored into the quota check.

This method will raise a QuotaResourceUnknown exception if a given resource is unknown or if it does not have a usage synchronization function.

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 a list of reservation UUIDs which were created.

Parameters:

• context – The request context, for access checks.
• expire – An optional parameter specifying an expiration time for the reservations. If it is a simple number, it is interpreted as a number of seconds and added to the current time; if it is a datetime.timedelta object, it will also be added to the current time. A datetime.datetime object will be interpreted as the absolute expiration time. If None is specified, the default expiration time set by –default-reservation-expire will be used (this value will be treated as a number of seconds).
• project_id – Specify the project_id if current context is admin and admin wants to impact on common user’s tenant.

resources

rollback(context, reservations, project_id=None)

Roll back reservations.

Parameters:

• context – The request context, for access checks.
• reservations – A list of the reservation UUIDs, as returned by the reserve() method.
• project_id – Specify the project_id if current context is admin and admin wants to impact on common user’s tenant.

usage_reset(context, resources)

Reset the usage records for a particular user on a list of resources. This will force that user’s usage records to be refreshed the next time a reservation is made.

Note: this does not affect the currently outstanding reservations the user has; those reservations must be committed or rolled back (or expired).

Parameters:

• context – The request context, for access checks.
• resources – A list of the resource names for which the usage must be reset.

class ReservableResource(name, sync, flag=None)

Bases: nova.quota.BaseResource

Describe a reservable resource.