What is Rack ?

@happynoff http://www.tinci.fr

What is Rack?Ruby don't hurt me, no more


bit.ly/what-rack


A Ruby Webserver Interface


Web Server Your Ruby Application

)!(@*#&$^%MiNsWaNWhOOPsWHaTeVer


Web Server Your Ruby ApplicationRack

Yup!Here you go!

Huh, I've this request… Do you

know what it's about?!



Huh, I've this request… Do you

know what it's about?!

Rack

Well, let me check…


Web Server Rack

Hey girl, there's this guy asking about a request and all…

Your Ruby Application

Of course! Here's for you.

Have fun!



Thanks, you're very kind.

Rack

Ok! Here is what I've made for

you.


Responses!


[ , , ]Status Headers Body


[ "200", { "Content-Type" => "text/html" }, ["Hello world!"] ]



HTTP GET /…



HTTP GET /…



env



env


Rack

Middleware

Middleware

Middleware

Middleware

Middleware

server

app


Rack

Middleware

Middleware

Middleware

Middleware

Middleware

app

server


Middle-what?


class MyMiddleware

end


class MyMiddleware def initialize(app) @app = app end

end


class MyMiddleware def initialize(app) @app = app end

def call(env) @app.call(env) end end


class Trollware def initialize(app) @app = app end

def call(env) status, headers, resp = @app.call(env) ["404", headers, resp.body] end end


And Rails?


$ rake middleware


use Rack::Sendfile use ActionDispatch::Static use Rack::Lock use #<ActiveSupport::Cache::Strategy::…> use Rack::Runtime use Rack::MethodOverride use ActionDispatch::RequestId use Rails::Rack::Logger use ActionDispatch::ShowExceptions use WebConsole::Middleware use ActionDispatch::DebugExceptions use ActionDispatch::RemoteIp use ActionDispatch::Reloader use ActionDispatch::Callbacks use ActiveRecord::Migration::CheckPending use ActiveRecord::ConnectionAdapters::… use ActiveRecord::QueryCache use ActionDispatch::Cookies use ActionDispatch::Session::CookieStore use ActionDispatch::Flash use ActionDispatch::ParamsParser use Rack::Head use Rack::ConditionalGet use Rack::ETag run MyApp::Application.routes


ActionDispatch::Static


ActionDispatch::ParamsParser


run MyApp::Application.routes


Resources


guides.rubyonrails.org/

rails_on_rack.html


https://github.com/rack/

rack-contrib

@happynoff

inciwww.tinci.fr

Simon Courtois, Software Architect at

Ruby on Rails, .NET, EmberJS


Questions?


Thanks

Technology

What is Rack ?