Blackhole proxy to block all external calls. Add following configs to your browser creation profile["network.proxy.type"] = 1 profile["network.proxy.http"] = "localhost" profile["network.proxy.http_port"] = 9001 no_proxy_list = "localhost, 127.0.0.1" no_proxy_list += ", #{ENV['PROXY_SERVER_WHITELIST']}" if ENV['PROXY_SERVER_WHITELIST'] profile["…

gistfile1.rb

require 'rubygems'
require 'em-proxy'
require 'http_parser.rb'
require 'uuid'
require 'uri'

PROXY_SERVER_HOST   = "127.0.0.1"
PROXY_SERVER_PORT   = ENV['PROXY_SERVER_PORT'] || 9001
output = "tmp/blocked_external_urls.log"

puts "Starting server #{PROXY_SERVER_HOST}:#{PROXY_SERVER_PORT}"

Proxy.start(:host => PROXY_SERVER_HOST, :port => PROXY_SERVER_PORT) do |conn|

  @p = Http::Parser.new
  @p.on_headers_complete = proc do |h|
   session = UUID.generate


   @request_host, request_port = h['Host'].split(':')


   File.open(output, 'a') {|f| f.write("#{@request_host}\n")}

   @request_host = "127.0.0.1"

   conn.server session, :host => @request_host, :port => (request_port || 80)
   conn.relay_to_servers @buffer

   @buffer = ''
  end

  @buffer = ''

  conn.on_connect do |data,b|

  end

  conn.on_data do |data|
   @buffer << data
   @p << data
   data
  end

  conn.on_response do |backend, resp|
   resp
  end

  conn.on_finish do |backend, name|

  end

end