DomainQuotaManagementAndEnforcement


 * Launchpad Entry: Domain Quota Management
 * Created: 03 March 2013
 * Contributors: Yehia Beyh, Glaucimar Aguiar, Tiago Martins, Akshat Kakkar Ulrich Schwickerath,

Introduction
In Keystone v3 (Grizzly release), Domains encapsulates users and projects into logical entities that can represent accounts, organizations, etc. Currently there is no capability or mechanism to manage or enforce quotas at domain level. Assigning or updating quota values or limits to a domain will allow the cloud administrator to evaluate domain lists and consumption. In order to achieve these capabilities it will be required to implement quota management for Keystone domains. The goal of this blueprint is to support quotas at the OpenStack Domain level. The design of the feature models, as far as possible, the style of project quotas. This blueprint is a contribution from CERN, BARC and Hewlett-Packard.

Openstack Quotas
Today OpenStack services make usage of quotas to limit the project resources. For example, the “Instances” quota represents the number of instances that can be created in a project. The table below summarizes the existing project quotas.

User Stories
Domain Quotas might impact partitioned OpenStack deployments (regions, cells, etc). Here we consider only the impact on regions. These can be
 * 1) Per–Region domain quotas
 * 2) Across region domain quotas

The 1st approach works similar to the current implementation of quotas per project; in a multi-region scenario, the domain quotas are enforced by each service in a non-centralized fashion. The 2nd approach, a domain quota is shared dynamically among regions, e.g. if a service from a given region needs more quota than the others, it requests more quotas. This blueprint addresses the per–region domain quotas. The user stories are listed below:
 * As a cloud administrator, I want to create a domain with default domain quotas
 * As a cloud/domain administrator, I want to see the domain quotas for a domain in a region
 * As a cloud administrator, I want to update the quotas for a domain in a region
 * As a cloud administrator, I want to delete the quotas for a domain in a region

Since quotas deals with sensible aspects of resource consumption, we identified the need to log the interactions of users when they manage domain quotas.

Design
Our proposal have 2 main blocks: one in keystone we are calling the Domain Quota Proxy (DQP), the other we are calling Domain Quota Driver (DQD). The DQP is responsible to give to user one point of domain quota management, so it acts as a proxy. The DQP is a discrete extesion that can be improved to serve as a single point of management for other quotas. The DQD is a piece of code located in the quota module of Nova, Cinder and Quantum projects, and it's designed in the same fashion as the other drivers present in such module.



Quota modules need to be refactored to add DQD. Also we should extend the services REST API to provide domain quotas usage to Domain Quota Proxy. The DQP is designed to be implemented as a discrete extension and not included in the default pipeline of Keystone. The Domain Quota Driver design is similar to the current quota driver from quota.py module, given the possibility to the user to option to use it or not; they will be responsible to enforce all quotas listed in the table above in the context of domains.

REST API
This gives an option of getting quota for specific domain. GET v3/{domain-id}/quotas Content-Type application/json Accept application/json Request: {   "quotas": { "region": "regionOne", "services": [ "nova", "cinder" ]   } } Normal Response Code: 200 Error Response Codes: Unauthorized (401), Not Found (404) Response: {   "quotas": [ [           {                "domain-id": "72415820-8b69-11e0-9b19-734f6acf67565", "region": "RegionOne" },           {                "nova": { "instances": 10, "cores": 20, "ram": 1024, "fixed_ips": -1, "floating_ips": 10, "metada_items": 128, "injected_files": 5, "injected_files_content_bytes": 1024, "injected_file_path_bytes": 255, "security_groups": 10, "security_groups_rules": 20, "key_pairs": 100 },               "cinder": { "volumes": 20, "snapshots": 10, "gigabytes": 2048 }           }        ]    ] }

This gives an option of updating quota for specific domain. POST v3/{domain-id}/quotas Content-Type application/json Accept application/json Request {  "quotas":{ "region":"RegionOne", "nova":{ "floating_ips": 30 }   } }  Normal Response Code: 200 Error Response Codes: Unauthorized (401), Not Found (404) Response: {   "quotas": [ [           {                "domain-id": "72415820-8b69-11e0-9b19-734f6acf67565", "region": "RegionOne" },           {                "nova": { "instances": 10, "cores": 20, "ram": 1024, "fixed_ips": -1, "floating_ips": 30, "metada_items": 128, "injected_files": 5, "injected_files_content_bytes": 1024, "injected_file_path_bytes": 255, "security_groups": 10, "security_groups_rules": 20, "key_pairs": 100 }           }        ]    ] }

This gives an option of deleting quota for specific domain. DELETE v3/{domain-id}/quotas Content-Type application/json Accept application/json Request: {   "quotas": { "region": "regionOne", "services": [ "nova", "cinder" ]   } } Normal Response Code: 200 Error Response Codes: Unauthorized (401), Not Found (404) Response: {   "quotas": [ [           {                "domain-id": "72415820-8b69-11e0-9b19-734f6acf67565", "region": "RegionOne" },           {                "nova": { "instances": 10, "cores": 20, "ram": 1024, "fixed_ips": -1, "floating_ips": 10, "metada_items": 128, "injected_files": 5, "injected_files_content_bytes": 1024, "injected_file_path_bytes": 255, "security_groups": 10, "security_groups_rules": 20, "key_pairs": 100 },               "cinder": { "volumes": 20, "snapshots": 10, "gigabytes": 2048 }           }        ]    ] }

Implementation
Tables are made generic enough so as to accommodate quotas for any resource of any service. 'quotas' table is capable enough to store quota for any entity (and not just domain). Entity for which a quota is set is called as child in generic terms. Entity responsible for managing quota of a child is called parent. A child and a parent, need not be described just by a single field like user-id alone. There can be multiple fields (like user-id, role, project-id, etc.) and its values which in combination describes a child or a parent. This can be seen as best represented in general by a dictionary. For simple DB implementation, it is suggested to store this dictionary as separate key-value data in separate tables. These tables are 'child_field_data' and 'parent_field_data' tables.

Details of fields of various DB tables is mentioned below,

Quota Table

Child_Field_Data Table

Parent_Field_Data Table

For history tracking, updates done in table < quota will be stored in the corresponding history table h_quota.

Open Stack Quota References
This is a list of URLs of work on quotas within OpenStack.