Re: rgw: feedback on auth engine selection

[Casey Bodley <cbodley@redhat.com>]

On 09/07/2016 01:19 PM, Radoslaw Zarzynski wrote:
> Anyway, before we start discussing the whole
> auth stuff further, I guess it would be helpful to
> write in one place all requirements/plans that
> might affect this area. For instance, the idea of
> RGWHandler rework can have such impact.
>
> Let me start the requirements with an item found
> after a session with Swift's FormPost middleware:
>
> * the auth infrastructure must allow for easy-adoption
>    of new AuthEngines as even FormPost would need
>    one :-).

Some specific requirements that I recall from our past discussions include:

- don't heap allocate auth state per request
- don't construct or call into AuthEngines that shouldn't be enabled for 
the given handler

I'll add some of the other refactoring goals we've discussed, but I 
don't think they place any strict requirements on the auth subsystem:

- RGWHandler: being able to reuse handler instances, instead of 
allocating a new one for each request
- req_state: contains too many unrelated fields, some of which are 
transformed in confusing ways over the lifetime of the request. needs to 
be broken up into smaller, better encapsulated sub-objects
- concurrency: move away from a synchronous process_request() to build 
on asio frontend work