[Catalyst] refactoring an existing HTML::Mason installation to use Catalyst

[Marc Espie]

Couldn't find any simple guide to that, so I was wondering if someone
had done it already.

I have a somewhat big HTML::Mason `classic' web-site, with web pages
that include all kinds of Mason components.

I'd like to migrate all of that to Catalyst, but it's not going to happen
overnight, and the application must keep running.

So I was wondering if there was any guide to this kind of `inside-out'
refactoring.

Specifically, I see how I can get the Mason app coexisting with Catalyst
stuff, I also have a plan to migrate the DBI glue to DBIx::Class, but I
would like to keep using the Mason infrastructure for now, and by able
to invoke catalyst parts as Mason components, e.g., a web page served
by mason:

some static content...
some mason stuff.
<& invoke/some/external_compoent /&>
   ^
   |
what should I put to be able to have part of my catalyst app there ?

I understand it will require having two views (full catalyst app, and 
html fragments for HTML::Mason), but I don't see how to run the controller
from Mason...