A very simple script that will write a "hello world" file and install Chef workstation. Put it on Dropbox or a web server to get an HTTPS URL, and use that as the SoftLayer provision script URL.

testDropbox.sh

#!/bin/bash

#=======================================================================
#    testDropbox.sh
#     © Copyright IBM Corporation 2014.
#    LICENSE: MIT (http://opensource.org/licenses/MIT)    
#=======================================================================

echo "hello world" > helloWorld.txt
curl -L https://www.opscode.com/chef/install.sh | bash

See my other SoftLayer bootstrap scripts at https://github.com/amfred/softlayerbootstrap. They are listed in the README.md file. MIT license, strictly AS-IS, use at your own risk.