feature: metrics server support ephemeral-storage metrics

[googs1025]

We seem to only have cpu memory and other indicators for a single pod at present.

root@VM-0-3-ubuntu:/home/ubuntu# curl localhost:8181/apis/metrics.k8s.io/v1beta1/namespaces/default/pods/example-pod-with-ephemeral-storage
{
  "kind": "PodMetrics",
  "apiVersion": "metrics.k8s.io/v1beta1",
  "metadata": {
    "name": "example-pod-with-ephemeral-storage",
    "namespace": "default",
    "creationTimestamp": "2025-01-09T13:46:04Z"
  },
  "timestamp": "2025-01-09T13:45:39Z",
  "window": "17.913s",
  "containers": [
    {
      "name": "example-container",
      "usage": {
        "cpu": "0",
        "memory": "4620Ki"
      }
    }
  ]
}

I would like to ask if there is any plan to support ephemeral storage metrics?

FYI: kubernetes/kubectl#1696 (comment)

/kind support
/kind feature

[richabanker]

cc @dgrisonnet
/triage accepted