em-proxy-http.rb

require 'em-proxy'
require 'http/parser'
require 'uuid'

# > ruby em-proxy-http.rb
# > curl --proxy localhost:9889 www.google.com

host = "0.0.0.0"
port = 9889
puts "listening on #{host}:#{port}..."

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

  @p = Http::Parser.new
  @p.on_headers_complete = proc do |h|
    session = UUID.generate
    puts "New session: #{session} (#{h.inspect})"

    host, port = h['Host'].split(':')
    conn.server session, :host => host, :port => (port || 80)
    conn.relay_to_servers @buffer

    @buffer.clear
  end

  @buffer = ''

  conn.on_connect do |data,b|
    puts [:on_connect, data, b].inspect
  end

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

    data
  end

  conn.on_response do |backend, resp|
    puts [:on_response, backend, resp].inspect
    resp
  end

  conn.on_finish do |backend, name|
    puts [:on_finish, name].inspect
  end
end

hey, thanks anyway :D

The proxy above do not handle HTTP/1.1 persistence connection.

To workaround this, i disabled the persistence connection on both client and server side (by adding Connection: close). Not a good example for implementing proxy, but it work fine as a proxy that work on modern browsers and sites. Check my fork here: https://gist.github.com/1560703

If you want an http proxy with persistent connections, etc, take a look at goliath + mongo logging example in there. What we're doing here is basically reimplementing all of the connection management that Goliath already provides. :-)

@igrigorik thanks! this seems what i'm looking for.