---
prelude: >
    This release leverages oslo.policy's policy-in-code feature to modify the
    default check strings and scope types for nearly all of keystone's API
    policies. These changes make the policies more precise than they were
    before, using the reader, member, and admin roles where previously only the
    admin role and a catch-all rule was available. The changes also take
    advantage of system, domain, and project scope, allowing you to create role
    assignments for your users that are appropriate to the actions they need to
    perform. Eventually this will allow you to set
    ``[oslo_policy]/enforce_scope=true`` in your keystone configuration, which
    simplifies access control management by ensuring that oslo.policy checks
    both the role and the scope on API requests. However, please be aware that
    not all policies have been converted in this release and some changes are
    still under development.

    During the transition phase, if you have not overridden a policy, the old
    default and the new default will be OR'd together. This means that, for
    example, where we have changed the policy rule from
    ``'rule:admin_required'`` to ``'role:reader and system_scope:all'``, both
    policy rules will be in effect. Please check your current policies and role
    assignments before upgrading to ensure the policies will not be too
    permissive for your deployment. To hide the deprecation warnings and opt
    into the less permissive rules, you can override the policy configuration
    to use the newer policy rule.

Add release prelude about changing policies
Add release prelude about changing policies

This change adds a prelude to the release notes to inform operators
about the changing policy defaults and how to handle them, since these
are going to be quite a big change and cause a lot of log warnings.

Change-Id: If067866daa8abbe41027018c260a3e01bddbb92f
Related-bug: #968696
