Well, these need to be set anyway for this resource to work (`aws_ebs_raid` is from [the aws cookbook](https://github.com/opscode-cookbooks/aws) which does not support IAM roles).

Actually it looks like there was [a recent change in the AWS cookbook related to this](https://github.com/opscode-cookbooks/aws/commit/357941aa56674cb23cd2701dbf9ca40b1099498e), so I might have to switch how this works if we want to support the most recent version of that cookbook.