gistfile1.txt

use strict;
use warnings;

use Plack::Request;
use Data::Dumper;
use LWP::UserAgent;

return sub {
    my $req = Plack::Request->new(shift);

    my $_req = HTTP::Request->new(                                                                                                       $req->method,
        $req->request_uri,
        $req->headers, 
        $req->raw_body
    );

    my $ua = LWP::UserAgent->new;
    my $res = $ua->request( $_req );

    my @res_header;
    $res->headers->scan(sub{
        push @res_header, @_;
    });

    [ $res->code, \@res_header, [$res->content] ];
};

gistfile2.txt

plackup -s AnyEvent