boto/botocore — pull request #14 by mafrosis (2013-01-23 03:57:02+00:00)
Title: Ensure HTTP 200 response when querying instance meta-data for IAMs role

When botocore looks for credentials it queries the AWS meta-data service over HTTP. If the instance doesn't have an IAMs role, this will return a 404 and cause an exception.

The fix is to check the response for a 200 first.

The symptoms for this were mentioned in issue #12.