Googling for what should be in the ENV variables gave all sorts of contradictory results - here’s what works:
# Rackspace export SDK_USERNAME="username" # Same as here: https://mycloud.rackspace.com/ export SDK_PASSWORD="password-to-login" # Not the API key. export SDK_PROVIDER="rackspace-us" # Or rackspace-uk
Just posting this here for Google - hopefully you find this and it helps you - I was frustrated for quite a while.
PS - I couldn’t find this information anywhere in Rackpsace’s official documentation - if you know what it is - please send over a link!