myapp.psgi

use strict;
use warnings;

use MyApp;
use Plack::Builder;

my $app = MyApp->apply_default_middlewares(MyApp->psgi_app);

builder {
    enable sub {
        my $app = shift;
        sub {
            my $env = shift;
            $env->{'psgi.url_scheme'} = 'https';
            $env->{SERVER_PORT} = 48443;
            return $app->($env);
        }   
    };  
    $app;
};  

nobuilder.psgi

use strict;
use warnings;

use MyApp;

my $app = MyApp->apply_default_middlewares(MyApp->psgi_app);

sub {
    my $env = shift;
    $env->{'psgi.url_scheme'} = 'https';
    $env->{SERVER_PORT} = 48443;
    return $app->($env);
};

rh.psgi

use strict;
use warnings;

use MyApp;
use Plack::Builder;
use Plack::Middleware::ReverseProxy;
use Plack::Middleware::RequestHeaders;

my $app = MyApp->apply_default_middlewares(MyApp->psgi_app);

builder {
    enable "RequestHeaders",
        set => [ "X-Forwarded-Port" => 48443, "X-Forwarded-Proto" => "https" ];
    enable "ReverseProxy";
    $app;
};