Adds below things for the implementation of framework for registering and
using default policy rules.
* Policy-in-code
The framework for registering and using default policy rules.
Rules should be defined and returned from a module in
masakari/policies/, and then added to the list in masakari/policies/__init__.py.
A new context.can() method has been added for policy enforcement of
registered rules. It has the same parameters as the enforce() method
currently being used.
* Add policy sample generation
The entry point and config file necessary for using the
oslo.policy sample generation script. It also adds a tox target to
simplify the usage of it.
* Add policy documentation and sample file
Documentation and sample file for default policy in code feature.
* Hacking check for policy registration
It ensures that policy registration happens in the centralized
masakari/policies/ directory.
* Hacking check for _ENFORCER.enforce()
Hacking check in order to ensure that only registered policies
are used for authorization checks _ENFORCER.authorize should be used rather
than _ENFORCER.enforce.
* Add entry_point for oslo policy scripts
There are two helper scripts in oslo.policy to help deployers understand
their policy configuration better. With the setup.cfg entry these can be
called directly from oslo.policy.
Changes done here are with the reference of [1] at NOVA side
which is contributed by Andrew Laski and Claudiu Belu
[1] https://review.openstack.org/#/q/topic:bp/policy-in-code+project:openstack/nova+status:merged
Change-Id: If885a66d92c31be440d27d6780635800a0b12e3e
shilpa.devharakar