No longer authorized to create AWS spot instances with Test Kitchen and ec2 driver


We are seeing a problem with running Test Kitchen using the "ec2" driver to spin up AWS EC2 spot instances.

Basically, we want to create spot instances to save money. So we have this line in our standard .kitchen.yml platform configuration for the "ec2" Test Kitchen driver:

spot_price: 0.100

This worked fine until recently. But this week users are getting this error when they do "kitchen create":

Failed to complete #create action: [You are not authorized to perform this operation.] on <instance>

If the user comments out the "spot_price" line above in their .kitchen.yml, it works -- but I assume we're getting a more-expensive on-demand instance instead of the cheaper spot instance we want.

I don't know enough about spot instances or Test Kitchen to know if this is the right place to ask, or whether I should contact our AWS support team. But I'll start here. Anybody out there have an idea what's going on here?

We are using ChefDK 2.5.3, which appears to include test-kitchen 1.20.0 and kitchen-ec2 2.2.1.

Thank you!