Rackspace operates in the US and the UK (with actually different accounts). See it's api docs:
To access the Authentication Service, you must know whether your account is US-based or UK-based:
• US-based accounts authenticate through https://auth.api.rackspacecloud.com/v1.0.
• UK-based accounts authenticate through https://lon.auth.api.rackspacecloud.com/v1.0.
Fog supports a rackspace_auth_url configuration option
(in /lib/fog/rackspace.rb line 15, for fog-0.3.26)
but knife's rackspace_server_create (_delete, _list) only supports two options:
So I think the different rackspace_server_*.rb files should have their connection object abstracted out into a common file and then this should have an optional rackspace_auth_url (default: nil, which will give existing behaviour)
No time to do this right now, cause I'm busy pushing my stuff onto rackspace us, to try to work around it, but does this sound like a way ahead?