1. Mangling CPAN with Plack::App::Proxy Olaf Alders Toronto Perl Mongers September 30, 2010 [email_address] twitter.com/wundercounter

2. What is PSGI/Plack? “ Superglue interface between perl web application frameworks and web servers, just like Perl is the duct tape of the internet. PSGI is an interface between Perl web applications and web servers, and Plack is a Perl module and toolkit that contains PSGI middleware, helpers and adapters to web servers. PSGI and Plack are inspired by Python's WSGI and Ruby's Rack.” http://plackperl.org

4. Doesn't require Apache

5. Doesn't appear to have the same security implications

7. I wish it had syntax highlighting

8. I don't want to use a Firefox plugin (Greasemonkey)

9. Using Plack, I will subvert CPAN to my will

10. I have also enlisted @ioncache to help me out

11. Introducing cpan-mangler http://github.com/oalders/cpan-mangler

12. Install and Run git clone http://github.com/ioncache/Plack-Middleware-HTMLify.git git clone http://github.com/oalders/cpan-mangler.git cpanm Plack Plack::App::Proxy cd cpan-mangler plackup -I../Plack-Middleware-HTMLify/lib

13. Documentation before:

15. Documentation after:

18. How about the module source?

19. Module source before:

21. Module source after:

23. Looking under the hood Let's look at how we went about setting up the proxy. It's very easy to set up. You can proxy a site of your choice in just a few minutes.

24. Set up the proxy use Plack::App::Proxy; use Plack::Builder; my $app = builder { mount "/" => builder {; Plack::App::Proxy->new( remote => 'http://search.cpan.org/' )->to_app; }; }; $app; # http://github.com/oalders/cpan-mangler/blob/master/examples/proxy.psgi

25. Mangle the POD use Plack::App::Proxy; use Plack::Builder; my $pod_highlight = q[...]; # insert JavaScript and CSS here my $app = builder { enable &quot;Debug&quot;, panels => [qw(Environment Memory Timer Response)]; mount &quot;/&quot; => builder { enable 'SimpleContentFilter', filter => sub { s{</head>}{$pod_highlight</head>}i; }; Plack::App::Proxy->new( remote => 'http://search.cpan.org/' )->to_app; }; }; $app; # Find full code sample at # http://github.com/oalders/cpan-mangler/blob/master/examples/pod-mangler.psgi

27. Can slow down page rendering on large pages (e.g. CGI.pm)

28. Some mangling may happen several times on a big page (chunking)

30. Improve your CPAN experience (be creative)

32. proxy an entire site

33. set up a custom domain name for the proxy

34. direct all Google ads to this new domain

35. mangle the pages to add your own analytics code

36. site's existing functionality should remain the same

37. you can now replicate a site for tracking without making a copy of it or knowing/caring how it works under the hood