= AwsSdbProxy

AwsSdbProxy is a HTTP proxy server bridging ActiveResource calls from Rails
to Amazon's SimpleDB Web Service allowing SimpleDB to be used as a storage
backend for Rails applications.

The proxy will listen on a configurable port for web service calls initiated by
ActiveResource models and forward the requests to SimpleDB using the aws-sdb
Gem by Tim Dysinger.

== Installation

Install the AwsSdbProxy plugin from Rubyforge[http://www.rubyforge.org] as
usual:

 script/plugin install http://rug-b.rubyforge.org/svn/aws_sdb_proxy

== Setup and Usage

1. Enter your Amazon Web Service credentials in the config/aws_sdb_proxy.yml
   config file (optionally configure server ports and a salt used to hash
   primary keys from the record content).
   
2. Check your available SimpleDB domains with <tt>rake aws_sdb:list_domains</tt> and
   create a new one with <tt>rake aws_sdb:create_domain DOMAIN=my_new_domain</tt>
   if necessary.
   
3. Start the AwsSdbProxy server with <tt>rake aws_sdb:start_proxy_in_foreground</tt>.
   (Once things are configured correctly you can also use
   <tt>rake aws_sdb:start_proxy</tt> to start the server as a background daemon.)

4. Connect any ActiveResource model to your SimpleDB domain, e.g.

    class Post < ActiveResource::Base
      self.site = "http://localhost:8888" # AwsSdbProxy host + port
      self.prefix = "/my_new_domain/"     # use your SimpleDB domain enclosed in /s
    end

5. Use your model just like any ActiveResource model in your application or try
   it in <tt>script/console</tt>, e.g.
   
    >> p = Post.create(:title => 'My first SimpleDB post')
    => #<Post:0x198ceec @prefix_options={}, @attributes={"updated_at"=>
    Sun Jan 20 00:42:43 UTC 2008, "title"=>"My first SimpleDB post",
    "id"=>1081408...01005954, "created_at"=>Sun Jan 20 00:42:43 UTC 2008}>

    >> p.body = 'Content is king'
    => "Content is king"
    
    >> p.save
    => true

    >> Post.find(:first, :params => { :title => 'My first SimpleDB post' })
    => #<Post:0x18efef8 @prefix_options={}, @attributes={"updated_at"=>
    Sun Jan 20 00:45:28 UTC 2008, "title"=>"My first SimpleDB post",
    "body"=>"Content is king", "id"=>1081408...01005954, "created_at"=>
    Sun Jan 20 00:42:43 UTC 2008}>


== Background
    
As you may have noticed SimpleDB (and thus AwsSdbProxy) do not use any
pre-defined schema. Every record can potentially have different attributes.
SimpleDB also has no data types associated with it's attributes, all data will
be stored as strings.

AwsSdbProxy adds a special <tt>_resource</tt> attribute to distinguish diffent models
within the same SimpleDB domain and also adds and handles the usual
<tt>created_at</tt> and <tt>updated_at</tt> attributes. Record ids are generated using
a SHA512 hash function to make key collisions extremely unlikely.

Copyright (c) 2008 mailto:[email protected], released under the MIT license