[Web-SIG] Python Web Modules - Version 0.5.0
ianb at colorstudy.com
Mon Jan 31 20:14:36 CET 2005
James Gardner wrote:
> Hello All,
> I'd like to announce the release of the Python Web Modules 0.5.0.
> This development release brings WSGI support to the modules.
> * Web Server Gateway Interface support - auth, error, database and session
> middleware and a WSGI Server.
Cool, good to see more of this kind of stuff. A couple of notes:
web.wsgi.cgi: is this safe when a piece of middleware changes
QUERY_STRING or otherwise rewrites the request? You can test for this
by saving the QUERY_STRING that you originally parsed alongside the
resulting FieldStorage, and then reparsing if they don't match. You can
even test for matching with "is", since you're really checking for
modifications instead of equality. The same should be possible for
wsgi.input and POST requests.
web.wsgi.session: I'd like to have some sort of standard for these
objects, at least some aspects. Not the details of storage, but mostly
access; along the lines of web.session.manager and/or .store. I'm not
sure how I feel about the manager with multiple applications, each of
which has a store -- I feel like this should be part of the
configuration somehow, which isn't necessarily part of the standard
web.wsgi.error: one standard I'd like for middleware would be some key
you could set that would indicate that some error handler exists, and
applications further down the stack shouldn't catch unexpected
exceptions (of course expected exceptions are a different matter). Then
the best error handler available would eventually get the error, and
process it somehow (e.g., mailing a report, displaying an error,
starting a debugger, etc). Anyway, something to think about for this.
web.wsgi.auth: I've been thinking lot about this as well, particularly
about the external interface. REMOTE_USER seems like a reasonable
enough place to put the login information. I'd like to keep
authorization and authentication separate -- one middleware determines
who you are, another (might) determine if you are allowed access.
Frequently only the application really knows if you are authorized,
based on logic that's beyond any ability to make it generic.
So I was thinking that status codes should be sufficient to communicate
authorization: 401 for login required, 403 for forbidden. If you are
doing cookie logins (which I generally prefer from a UI perspective) the
middleware can translate the 401 into a redirect to the login page. And
the 403 can turn into a nicer error page -- a piece of middleware for
indicating error pages would also be nice (similar to Apache's
Since there's a huge number of ways to log someone in, keeping these
concerns separate seems good. Apache and Zope are good counterexamples
where they combined too many aspects of authentication and authorization
into one bundle.
Ian Bicking / ianb at colorstudy.com / http://blog.ianbicking.org
More information about the Web-SIG