[Web-SIG] serving (potentially large) files through wsgi?

[Manlio Perillo]

Phillip J. Eby ha scritto:
> At 09:06 PM 12/17/2007 +0100, Manlio Perillo wrote:
>> Phillip J. Eby ha scritto:
>>> This is precisely why WSGI doesn't really have any "configuration" 
>>> defined, because the whole idea is that it should be as 
>>> "plug-and-play" as possible.  Server-level configuration options are 
>>> a liability to be avoided, a sometimes-necessary evil.  They aren't a 
>>> feature.
>>
>> Disagree.
> 
> Note that your disagreement doesn't retroactively change WSGI's design 
> goals or rationale, 


I disagree with your "Server-level configuration options are a liability 
to be avoided, a sometimes-necessary evil" phrase.

But now I'm not sure of what do you mean by "configuration".

> which are what I've been explaining.  Your desire 
> for configuration in one place also doesn't negate others' desires to 
> simply drop applications into a server with only the most minimal server 
> configuration possible.
> 

But some applications/middlewares *will* need some configuration;
maybe they have safe defaults for configuration parameters, but my 
problem is: how should these configuration parameters handled?


Let's make an example.
I want to add a middleware to my application that will send an email 
when an error occurs.

Of course I need to configure some parameters: how do you do this in WSGI?

Since the WSGI spec says nothing about configuration, this is up to the 
user.


In mod_wsgi for nginx I have added a `wsgi_middleware` directive, so 
that it is possible to stack middlewares from nginx configuration (and I 
think this can be very convenient).

Now, the only method for passing configuration parameters to a 
middleware is to set them in the WSGI environment dictionary, using the 
`wsgi_var` directive.

So, *all* the configuration (nginx server, application, middlewares) can 
be placed (and, IMHO, should be placed) in the nginx configuration file.


I hope that now it is clear what I mean (unfortunalely I'm not very good 
at explaining things).



Manlio Perillo