Describe Keystone architecture

Difficulty: unrated

Source: bregman-arie/devops-exercises by Arie Bregman

Answer

There is a service API and admin API through which Keystone gets requests
- Keystone has four backends:
  - Token Backend - Temporary Tokens for users and services
  - Policy Backend - Rules management and authorization
  - Identity Backend - users and groups (either standalone DB, LDAP, ...)
  - Catalog Backend - Endpoints
- It has pluggable environment where you can integrate with:
  - LDAP
  - KVS (Key Value Store)
  - SQL
  - PAM
  - Memcached