Plack is one of these wonderful adventures in the modern Perl world that makes it fun to write Web applications in Perl again. But I have a few applications written with Apache/mod_perl and they are not fun to work with. So what would you do?
One option would be to take the long road and port these apps to use Plack instead of messing around with Apache2::RequestRec. For this to work you might need to review the full code base before seeing any signs of progress.
Another option is to mock your Apache2::RequestRec object using Plack. This is the road explored by Plack::App::WrapApacheReq. With very little work this enables you to run your mod_perl application with any Plack handler you want. You can run your application as a stand alone server or serve it with nginx trough FastCGI.
But the fun doesn't stop here. Debugging and profiling mod_perl have always been a PITA, but with Plack::App::WrapApacheReq it is easy. Just take the generic.psgi example and it enables you to run the Perl debugger easy or just to use NYTProf on your request handling code.
The initial ideas for writing Plack::App::WrapApacheRec came from my mocking code to test a legacy mod_perl application. Even this gets more fun by using Plack. I havn't tested it yet, but with Plack::Test and Plack::Test::ExternalServer it should be trivial to run the same set of tests directly in a single process test suite or against your deployed server.
Plack::App::WrapApacheRec is still in it's infancy. It only mocks as much of Apache2::RequestRec as I need to run a single legacy application and to run Plack::Handler::Apache2 (as an absurd example, but yes we are self hosting). But I think that with very little work we should be able to run most mod_perl applications. Take it out for a ride, if it complains about a missing method please report it with CPAN's RequestTracker. Patches would be appreciated (or pull requests on github), but just a list of unimplemented method you need would be excellent.
Plack is fun, now working with mod_perl applications might become fun too.