Support out-tree cloud-providers #2
Description
RKE has built-in support for (legacy) in-tree cloud providers deployment (AWS, Azure, OpenStack and vSphere), this limits deployment scenarios where a different cloud-provider is needed. Yagan should support out-tree cloud providers listed in kubernetes official repos through HCL-defined resources as well as allowing a bring your own CCM approach.
So defining a variable like cloud_provider = "openstack" along with credentials and additional configuration enables the openstack out-tree provider within RKE.