Render a picture in non-public folder in Mojolicious

gistfile1.pl

#!/usr/bin/env perl
use Mojolicious::Lite;

get '/' => sub {
    my $self = shift;
	$self->render('clock');
};

get '/pic' => sub {
	my $self = shift;
	my $src = '/opt/private-folder/good.png';

	$self->res->headers->content_type('image/png');
	$self->res->content->asset(Mojo::Asset::File->new(path => $src )); 
	$self->rendered();
};

app->start;
__DATA__

@@ clock.html.ep
% use Time::Piece;
% my $now = localtime;
The time is <%= $now->hms %>.
<img src="http://127.0.0.1:3000/pic"/>