HTTP::Proxy::HeaderFilter

• This is the base class for manipulating message headers

• The filter() method has the following signature:

      sub filter {
          my ( $self, $headers, $message ) = @_;
          ...
      }

• The filter can create a response and make the proxy send it directly by using the proxy response() accessor.

      $filter = HTTP::Proxy::HeaderFilter::simple->new(
          sub {
              my ( $self, $headers, $message ) = @_;
              # random error
              $self->proxy->response(
                  HTTP::Response->new(
                      403, 
                      "<h1>Nothing to see here, move along.</h1>",
                      [ 'Content-Type' => 'text/html' ]
                  )
              ) if rand > .7;
          }
      );

• This completely shortcuts the origin server