Redirect Proxy

redirect_proxy.rb

#!/usr/bin/ruby

require 'webrick/httpproxy'
require 'optparse'

# Monkey patch HTTPRequest so we can modify the url and cookie
class WEBrick::HTTPRequest
	def update_uri(uri)
		@unparsed_uri = uri
		@request_uri = parse_uri(uri)
	end

	def set_cookie(cookie)
		@header['cookie'] = [cookie]
	end
end

def redirect_request(req, res)
	if @options[:from] == req.request_uri.to_s
		puts "Redirecting from #{@options[:from]} to #{@options[:to]}"

		puts @options[:cookie]
		req.set_cookie(@options[:cookie]) if @options[:cookie]
		req.update_uri(@options[:to])
	end
end

@options = {}

optparse = OptionParser.new do |opts|
	opts.banner = 'Usage: redirect_proxy.rb [options] from to'

	@options[:cookie] = nil
	opts.on('-c', '--cookie COOKIE', 'Set cookie when redirecting requests') do |cookie|
		@options[:cookie] = cookie
	end

	@options[:forwardproxy] = nil
	opts.on('-f', '--forwardproxy PROXY', 'Pass requests through a proxy') do |proxy|
		@options[:proxy] = URI::parse(proxy)
	end

	@options[:port] = 9999
	opts.on('-p', '--port PORT', 'Port to host the proxy on') do |port|
		@options[:port] = port
	end

	opts.on('-h', '--help', 'Displays this screen') do
		puts opts
		exit
	end
end

begin
	optparse.parse!
rescue
	puts optparse
	exit(-1)
end

if ARGV.length < 2
	puts optparse
	exit(-1)
end

@options[:from] = ARGV[0]
@options[:to] = ARGV[1]

server = WEBrick::HTTPProxyServer.new :Port=> @options[:port],
	:ProxyVia => @options[:forwardproxy],
	:ProxyURI => @options[:forwardproxy],
	:RequestCallback => method(:redirect_request)

trap "INT" do server.shutdown end
server.start