Some examples for my "Rack basics" slides :)

config.ru

class Wadus
  def call(env)
    ['200', {'X-Wadus' => 'Foo'}, ['Rack app with config.ru file']]
  end
end
run Wadus.new

logger_middleware.rb

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

  def call(env)
    before = Time.now.to_f
    status, headers, body = @app.call(env)
    after = Time.now.to_f
    puts "[LOGGER] Request time: #{after - before} sec."

    [status, headers, body]
  end
end

rack-class.rb

require 'rack'
class Wadus
  def call(env)
    ['200', {'X-Wadus' => 'Foo'}, ['Class based so simple rack app']]
  end
end
Rack::Handler::WEBrick.run Wadus.new

rack-proc.rb

require 'rack'
app = -> (env) do
  ['200', {'X-Wadus' => 'foo'}, ['Proc based so simple rack app']]
end
Rack::Handler::WEBrick.run app