SwiftPolicy Middleware
----------------------

The SwiftPolicy Middleware for OpenStack Swift allows to use a JSON policy file 
to handle swift authorizations.

SwiftPolicy is an adaptation of the keystoneauth middleware here:
https://github.com/openstack/swift/blob/master/swift/common/middleware/keystoneauth.py


Install
-------

1) Install SwiftPolicy  with ``sudo python setup.py install`` or ``sudo python
   setup.py develop``.

2) Alter your proxy-server.conf pipeline to include SwiftPolicy:

For example, you can use SwiftPolicy in place of the keystoneauth middleware:

    Change::

        [pipeline:main]
        pipeline = catch_errors cache tempauth proxy-server

    To::

        [pipeline:main]
        pipeline = catch_errors cache swiftpolicy tempauth proxy-server

3) Add to your proxy-server.conf the section for the SwiftPolicy WSGI filter.

The policy file is set with the ``policy`` option ::

    [filter:swift3]
    use = egg:swiftpolicy#swiftpolicy
    policy = %(here)s/default.json

This middleware comes with a default policy file in /etc/swift/default.json that maintains
compatibility with keystoneauth.


Policy file
-----------

The policy file will list all possible actions on a swift proxy.
Action's syntax is: ``<http verb>_<swift entity>`` (example: "get_container", "put_object", etc).

    ...
    "get_container": "rule:allowed_for_user",
    "put_container": "rule:allowed_for_user",
    "delete_container": "rule:allowed_for_user",
    ...


The policy file contains also two specific rules: "swift_owner" "reseller_request", they are defined
when swift_owner and reseller_request headers are set to true, as those two values are part
of the contract with the auth system (more details here: http://docs.openstack.org/developer/swift/overview_auth.html)

    ...
    "swift_owner": "rule:swift_reseller or rule:swift_operator",
    "reseller_request": "rule:swift_reseller",
    ...
 
Example
-------

* To forbid the creation of new containers: set put_container to '!':

        ...
        "get_container": "rule:allowed_for_user",
        "put_container": "!",
        ...

* To restrict the creation of new containers to users with the role "admin":

        ...
        "get_container": "rule:allowed_for_user",
        "put_container": "role:admin",
        ...

Limitations
-----------

* swiftpolicy does not support dynamic reload of policies, and thus, the swift proxy has
to be restarted when the policy file is updated.