Support for pre-existing credentials in ~/.aws/credentials

[dzierzanowski]

Hi, the idea of granted seems amazing. However, I could not manage to get it to work with my current setup, where I assume a bunch of roles using a script that dumps the credential triples (key ID, secret key, session token) into ~/.aws/credentials. The error I'm getting is:

[✘] operation error STS: GetFederationToken, https response error StatusCode: 403, RequestID: xxxxxxxx-..., api error AccessDenied: Cannot call GetFederationToken with session credentials

The docs say that it is possible to use existing credentials, but it only seems to work if they are in environment variables: https://docs.commonfate.io/granted/usage/console#launching-the-console-with-existing-credentials

It would be great to have granted support sourcing these credentials from the file.