zip -r kiwi_farmer.zip .
iron worker upload --zip kiwi_farmer.zip --name kiwi_farmer iron/images:ruby-2.1 ruby kiwi_farmer.rb
With --payload-file option can set up your credential file path, so you don't need upload your credential to IronWorker.
iron worker queue --payload-file ../config/config.json --wait kiwi_farmer