Cloud-init per-boot script doing nothing

I am new to cloud-init, my final goal is to run an R script each time an EC2 Spot Instance becomes active, but in order to test it I created an on-demand Ubuntu 12.04 instance and created a simple script but nothing happens after reboot. Here are the steps I took:

• Launched the new Ubunut 12.04 instance
• Navigate to /var/lib/cloud/scripts/per-boot
• sudo vi script.sh
• Added the following code:

#!/bin/sh
echo "test"

• sudo reboot

At this point I thought I should see a "test" print when the instance reboots, but there is nothing there. I went to take a look at /var/log/cloud-init.log but there is no error or anything out of the ordinary.

I am clearly missing something so any tip in the right direction will be much appreciated!

Thanks!

It won't run unless the scripts user is set to always run. See this answer for more details (and for instructions on how to get scripts to run on reboot, generally).