Automatic merge from submit-queue
Rackspace improvements (OpenStack Cinder)
This adds PV support via Cinder on Rackspace clusters. Rackspace Cloud Block Storage is pretty much vanilla OpenStack Cinder, so there is no need for a separate Volume Plugin. Instead I refactored the Cinder/OpenStack interaction a bit (by introducing a CinderProvider Interface and moving the device path detection logic to the OpenStack part).
Right now this is limited to `AttachDisk` and `DetachDisk`. Creation and deletion of Block Storage is not in scope of this PR.
Also the `ExternalID` and `InstanceID` cloud provider methods have been implemented for Rackspace.
This is a better abstraction than passing in specific pieces of the
Service that each of the cloudproviders may or may not need. For
instance, many of the providers don't need a region, yet this is passed
in. Similarly many of the providers want a string IP for the load
balancer, but it passes in a converted net ip. Affinity is unused by
AWS. A provider change may also require adding a new parameter which has
an effect on all other cloud provider implementations.
Further, this will simplify adding provider specific load balancer
options, such as with labels or some other metadata. For example, we
could add labels for configuring the details of an AWS elastic load
balancer, such as idle timeout on connections, whether it is
internal or external, cross-zone load balancing, and so on.
Authors: @chbatey, @jsravn
Volume names have now format <cluster-name>-dynamic-<pv-name>.
pv-name is guaranteed to be unique in Kubernetes cluster, adding
<cluster-name> ensures we don't conflict with any running cluster
in the cloud project (kube-controller-manager --cluster-name=XXX).
'kubernetes' is the default cluster name.
This synchronizes Cinder with AWS EBS code, where we already tag volumes with
claim.Namespace and claim.Name (and pv.Name, as suggested in separate PR).
Cole Mickens