Support for AWS Credentials in Provider Authentication #273
Description
Currently, the Redpanda provider has auth overrides for BYOC in Azure and GCP, however, it appears the only supported auth mechanism for BYOC in AWS is to populate the environment with AWS variables.
This is inconvenient for us, because our backend is S3, and we are already using the environment variables to facilitate the backend auth. When we first ran a cluster creation, this provider just assumed that the valid credentials in the environment represented a role that should be used to create the cluster, and it was spun up in the wrong account.
If the provider had options to configure role assumption, we could populate those separately.