select-oci-auth selects an image registry authentication credential from an
authentication file. By default, it reads from
$HOME/.docker/config.json. Alternative authentication file can be specified
via environment variable AUTHFILE.
The script matches a credential by either a registry or an image repository. For example,
select-oci-auth quay.io
select-oci-auth registry.io/foo/bar:0.3@sha256:1234567...
As you can see, the input image reference can have tag and digest, script ignores them.