Rack::Builder rackup

Posted on In ,

rackup converts the supplied rack config file to an instance of Rack::Builder. This is how is happens under the hood ( just so you get an idea ) :

config_file = File.read(config)
rack_application = eval("Rack::Builder.new { #{config_file} }")

And then rackup supplies rack_application to the respective webserver :

server.run rack_application, options

Very straight forward! In short, rack config files are evaluated within the context of a Rack::Builder object. So if we convert infinity to a rack config file which rackup can understand :

# infinity.ru

infinity = Proc.new {|env| [200, {"Content-Type" => "text/html"}, env.inspect]}

use Rack::CommonLogger

map '/' do
  run infinity
end

map '/version' do
  map '/' do
    run Proc.new {|env| [200, {"Content-Type" => "text/html"}, "infinity 0.1"] }
  end

  map '/last' do
    run Proc.new {|env| [200, {"Content-Type" => "text/html"}, "infinity beta 0.0"] }
  end
end

And now run it :
rackup infinity.ru