It works! Add a first-pass rackup adapter which also works.

README.md

@@ -1,3 +1,24 @@
-This is almost verbatim from Zed Shaw's python connector for mongrel2, which you can see here: http://mongrel2.org/dir?ci=1bdfff8f050b97df&name=examples/python/mongrel2
+m2r
+===
 
-You'll need a recent 1.9 ruby and FFI and http://github.com/chuckremes/ffi-rzmq, oh, and Zero MQ. Run: `ruby example/http_0mq.rb`
+A [mongrel2](http://mongrel2.org/index) backend handler written in Ruby, based on [Zed's Python backend handler](http://mongrel2.org/dir?ci=1bdfff8f050b97df&name=examples/python/mongrel2).
+
+Usage/Examples
+-----
+
+* `examples/http_0mq.rb` is a test little servlet thing (based on what comes with mongrel2)and there is also a rack handler at 
+* `examples/rack_handler.rb` is a Mongrel2 ruby handler rack handler mouthful, whose variables are probably a little off
+* `examples/lobster.ru` is a rackup file using the Rack handler that'll serve Rack's funny little lobster app.
+
+Run:
+* `ruby examples/http_0mq.rb`, which with Mongrel2's test config will serve up at http://localhost:6767/handlertest
+* `rackup examples/lobster.ru`, ditto, http://localhost:6767/handlertest
+
+Installation
+------------
+
+* Ruby 1.9ish (RVM saved my life here)
+* [FFI](http://github.com/ffi/ffi), `gem install ffi` should be fine
+* [Zero MQ](http://www.zeromq.org/area:download)
+* [ffi-rzmq](http://github.com/chuckremes/ffi-rzmq), which you'll have to build. The native zmq didn't work for me, but if you want to fix it, please do!
+* Rack (gem install rack) if you want to run the rack example.

connection.rb

@@ -7,21 +7,11 @@
 gem 'json'
 require 'ffi-rzmq'
 require 'json'
+
 $: << File.dirname(__FILE__)
 require 'request'
 
 CTX = ZMQ::Context.new(1)
-HTTP_FORMAT = "HTTP/1.1 %(code)s %(status)s\r\n%(headers)s\r\n\r\n%(body)s"
-
-class String
-  # Match python's % function
-  def |(args)
-    args.inject(self.dup) do |copy, (key, val)|
-      copy.gsub!(/%\(#{key.to_s}\)/, val.to_s)
-      copy
-    end
-  end
-end
 
 module Mongrel2
   # A Connection object manages the connection between your handler
@@ -86,8 +76,8 @@ def reply_json(req, data)
     # Basic HTTP response mechanism which will take your body,
     # any headers you've made, and encode them so that the 
     # browser gets them.
-    def reply_http(req, body, code=200, status="OK", headers={})
-      self.reply(req, http_response(body, code, status, headers))
+    def reply_http(req, body, code=200, headers={})
+      self.reply(req, http_response(body, code, headers))
     end
 
     # This lets you send a single message to many currently
@@ -108,17 +98,60 @@ def deliver_json(idents, data)
     # Same as deliver, but builds an HTTP response, which means, yes,
     # you can reply to multiple connected clients waiting for an HTTP 
     # response from one handler.  Kinda cool.
-    def deliver_http(idents, body, code=200, status="OK", headers={})
-      self.deliver(idents, http_response(body, code, status, headers))
+    def deliver_http(idents, body, code=200, headers={})
+      self.deliver(idents, http_response(body, code, headers))
     end
 
     private
-    def http_response(body, code, status, headers)
-      payload = {'code' => code, 'status' => status, 'body' => body}
+    def http_response(body, code, headers)
       headers['Content-Length'] = body.size
-      payload['headers'] = headers.map{|k, v| "%s: %s" % [k,v]}.join("\r\n")
+      headers_s = headers.map{|k, v| "%s: %s" % [k,v]}.join("\r\n")
 
-      HTTP_FORMAT | payload
+      "HTTP/1.1 #{code} #{StatusMessage[code.to_i]}\r\n#{headers_s}\r\n\r\n#{body}"
     end
+
+    # From WEBrick: thanks dawg.
+    StatusMessage = {
+      100 => 'Continue',
+      101 => 'Switching Protocols',
+      200 => 'OK',
+      201 => 'Created',
+      202 => 'Accepted',
+      203 => 'Non-Authoritative Information',
+      204 => 'No Content',
+      205 => 'Reset Content',
+      206 => 'Partial Content',
+      300 => 'Multiple Choices',
+      301 => 'Moved Permanently',
+      302 => 'Found',
+      303 => 'See Other',
+      304 => 'Not Modified',
+      305 => 'Use Proxy',
+      307 => 'Temporary Redirect',
+      400 => 'Bad Request',
+      401 => 'Unauthorized',
+      402 => 'Payment Required',
+      403 => 'Forbidden',
+      404 => 'Not Found',
+      405 => 'Method Not Allowed',
+      406 => 'Not Acceptable',
+      407 => 'Proxy Authentication Required',
+      408 => 'Request Timeout',
+      409 => 'Conflict',
+      410 => 'Gone',
+      411 => 'Length Required',
+      412 => 'Precondition Failed',
+      413 => 'Request Entity Too Large',
+      414 => 'Request-URI Too Large',
+      415 => 'Unsupported Media Type',
+      416 => 'Request Range Not Satisfiable',
+      417 => 'Expectation Failed',
+      500 => 'Internal Server Error',
+      501 => 'Not Implemented',
+      502 => 'Bad Gateway',
+      503 => 'Service Unavailable',
+      504 => 'Gateway Timeout',
+      505 => 'HTTP Version Not Supported'
+    }
   end # class Connection
 end # mod Mongrel2

example/lobster.ru

@@ -0,0 +1,7 @@
+require 'rack/lobster'
+$: << File.dirname(__FILE__)
+require 'rack_handler'
+
+use Rack::ShowExceptions
+puts "Lobster at http://localhost:6767/handlertest"
+Rack::Handler::Mongrel2Handler.run Rack::Lobster.new

example/rack_handler.rb

@@ -0,0 +1,57 @@
+require 'rubygems'
+require 'rack'
+require 'stringio'
+# require 'ruby-debug'
+# Debugger.start
+# gem install ruby-debug19 -- --with-ruby-include=$HOME/.rvm/src/ruby-1.9.2-head
+
+$: << File.expand_path(File.dirname(__FILE__) + '/..')
+require 'connection'
+
+$sender_id = "70D107AB-19F5-44AE-A2D0-2326A167D8D7"
+
+module Rack
+  module Handler
+    class Mongrel2Handler
+      def self.run(app, receive = "tcp://127.0.0.1:9997", send = "tcp://127.0.0.1:9996")
+        conn = Mongrel2::Connection.new($sender_id, receive, send)
+        while true
+          puts "WAITING FOR REQUEST"
+
+          req = conn.recv
+
+          if req.is_disconnect
+            puts "DICONNECT"
+            next
+          end
+
+          env = {
+            "rack.version" => Rack::VERSION,
+            "rack.url_scheme" => "http",
+            "rack.input" => StringIO.new(req.body),
+            "rack.errors" => $stderr,
+            "rack.multithread" => true,
+            "rack.multiprocess" => true,
+            "rack.run_once" => false,
+            "REQUEST_METHOD" => req.headers["METHOD"],
+            "SCRIPT_NAME" => "",
+            "PATH_INFO" => env["PATH"],
+            "QUERY_STRING" => env["QUERY"]
+          }
+
+          env["SERVER_NAME"], env["SERVER_PORT"] = req.headers["Host"].split(':', 2)
+          req.headers.each do |key, val|
+            unless key =~ /content_(type|length)/i
+              key = "HTTP_#{key.upcase}"
+            end
+            env[key] = val
+          end
+
+          status, headers, rack_response = app.call(env)
+          conn.reply_http(req, rack_response.body.join, status, headers)
+        end
+      end
+    end
+  end
+end
+