route 53
At work, we created an internal API for vending sub-domains of a particular, somewhat popular domain we own. The project is written in Go and wraps the AWS Route 53 API to manage DNS records. We decided to use github.com/mitchellh/goamz, which is has pretty well-rounded implementations of most of the AWS APIs. When using goamz/route53, things were working perfectly when aws.GetAuth was passed credentials directly–i.e., the things I normally set as AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY.