[Web-SIG] Standardised configuration and temporary directories.

[Paul Boddie]

Alan Kennedy wrote:
>
> On thinking about the configuration issue further on the way into
work, 
> I've changed my mind :-)
> 
> The original two options I presented for configuration were
> 
> A: By a specialised middleware component.
> 
> B: In the server configuration file. (I will now call this the
"platform 
> configuration file").
> 
> I originally thought that option B was the best, but now I think 
> differently. And from what I read from your post, Paul, I think we're
in 
> agreement.

Are we? ;-) Certain things like sessions are most likely to be
configured in
the server environment. In Tomcat, for example, that would be in one of
the
XML configuration files, but for something like Apache/mod_python it
would
be nicest to use httpd.conf or a related file, and Webware and Zope
store
sessions in their own particular way - note that Zope uses its own
special
mechanisms which might not correspond exactly with the conceptual model
you
envisage.

> Configuring the middleware stack is really the entire purpose of a 
> python WSGI server. The platform in which the server and application 
> reside, e.g. Apache, CGI, Tomcat, etc, should not be relevant.
Instead, 
> in an ideal scenario, the entire python application, i.e. server + 
> middleware + configuration, should be portable to another
platform(+WSGI 
> layer).

That's what WebStack is about: the same code runs on the seven supported
frameworks without any changes. Currently, the only server configuration
required consists of the following kinds of activities:

  * Add directives to Apache's httpd.conf (for anything using Apache).
  * Add context definitions to Webware's configuration.
  * Prepare a .war file for a Java servlet container.
  * Add a product to a Zope 2 instance.

Some interaction with the server configuration is clearly going to be
necessary.

> If this is to be the case, then the middleware and its configuration 
> would be best kept under centralised python control, which would 
> facilitate maximum portability between platforms.

I think what we agree on is that much of an application's configuration
can
be done at a fairly high level. An application which stores stuff in the
filesystem or which uses a database system doesn't necessarily need to
have
that kind of configuration entered into web.xml or httpd.conf, and it
should
be possible to keep that configuration portable, although I can imagine
complications with things like Tomcat which define JDBC connections in
the
XML configuration files.

Paul