[Zope3-dev] HEADS UP: PAU (pluggable authentication) users

[Garrett Smith]

Jim Fulton wrote:
> Garrett Smith wrote:
>> Later today I'm going to checkin a major refactor of the pluggable
>> authentication utility. The change greatly simplifies the end-user
>> experience of configuring the PAU and will make custom plugins
>> easier to write.
> 
> This introduces IAuthentication2.  This is meant to replace
> IAuthentication eventually.  IAuthentication will be deprecated.  The
> problem is that we now look up IAuthentication2 rather than
> IAuthentication.  This will cause a serious backward compatibility
> problem for people using other authentication utilities.  This will
> be the case for Zope X3.0 installations. that upgrade to X3.1.
> 
> I don't think there were ever many auth services.  Perhaps the old
> pluggableauth is the only one we need to worry about.  I suggest we
> do *one of*: 
> 
> - Make the old pluggable authentication thing support IAthentication2.
>    Unfortunately, we'd need a database fixup script that converted old
>    IAuthentication registrations to use IAuthentication2.  We may
>    already have code that converts old service registrations to
>    utility registrations. Maybe this code could do this too.
> 
>    or
> 
> - Change the code that doesn't actually *need* the new logout method
>    to do getUtility with IAuthentication, rather than
> IAuthentication2. 

The downside to option two is that there are a number of such places and
the BBB code starts to look like TODOs. I think this is one of the
problems of the interface + '2' evolution/migration scheme, but maybe
that's just the way it goes.

A third option would be to scrap IAuthentication2 and use adapters. It
would be nice to have a working example of interface evolution, but it
makes for complicated BBB/TODO management.

 -- Garrett