Multiplexing Proxy

client request

curl http://localhost:9999 -d destip=127.0.0.1

MultiplexingProxy.rb

require "rubygems"
require "webrick/httpproxy"

module WEBrick
  class HTTPRequest
    attr_writer :host, :port, :request_uri, :unparsed_uri, :request_line, :path
  end
end

class MultiplexingProxy < WEBrick::HTTPProxyServer

  def initialize(options)
    super(options)
  end
  
  def service(req, res)
    puts "*" * 50
    dest = destination(req)
    puts "Destination: #{dest}"

    site_uri = URI.parse(dest)
    req.host = req.request_uri.host = site_uri.host
    req.port = req.request_uri.port = site_uri.port
    req.request_line.gsub(/^(\w+) .+ (HTTP.+)$/, "#{$1} #{req.path} #{$2}")
    req.unparsed_uri = req.path
    
    super(req, res)
    print_response(res)
  end
  
  def destination(req)
    req.body.match(/destip=(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/)[1]
  end

  def print_response(res)
    puts "="*50 + res.body + "="*50
  end
end

s = MultiplexingProxy.new(:Port => 9999)
trap("INT") {s.shutdown}
s.start