WIP v0 NVIDIA GPU support

Implements part of #24071

I am not familiar with the scheduler enough to know what to do with the scores. Punting for now.

Missing items from the implementation plan: limitranger, rkt support, kubectl
support and user docs

pkg/api/types.go

@@ -1917,6 +1917,11 @@ type NodeResources struct {
 // ResourceName is the name identifying various resources in a ResourceList.
 type ResourceName string
 
+// Resource names must be not more than 63 characters, consisting of upper- or lower-case alphanumeric characters,
+// with the -, _, and . characters allowed anywhere, except the first or last character.
+// The default convention, matching that for annotations, is to use lower-case names, with dashes, rather than
+// camel case, separating compound words.
+// Fully-qualified resource typenames are constructed from a DNS-style subdomain, followed by a slash `/` and a name.
 const (
 	// CPU, in cores. (500m = .5 cores)
 	ResourceCPU ResourceName = "cpu"
@@ -1924,6 +1929,8 @@ const (
 	ResourceMemory ResourceName = "memory"
 	// Volume size, in bytes (e,g. 5Gi = 5GiB = 5 * 1024 * 1024 * 1024)
 	ResourceStorage ResourceName = "storage"
+	// NVIDIA GPU, in devices. Alpha, might change: although fractional and allowing values >1, only one whole device per node is assigned.
+	ResourceNvidiaGPU ResourceName = "alpha.kubernetes.io/nvidia-gpu"
 	// Number of Pods that may be running on this Node: see ResourcePods
 )