class Puma::Configuration

def app


the rackup file, and set @app.
Load the specified rackup file, pull options from 
def app
  found = options[:app] || load_rackup
  if @options[:log_requests]
    require_relative 'commonlogger'
    logger = @options[:logger]
    found = CommonLogger.new(found, logger)
  end
  ConfigMiddleware.new(self, found)
end