// user-initiated activities such as debugging. Ephemeral containers have no resource or
// scheduling guarantees, and they will not be restarted when they exit or when a Pod is
// removed or restarted. The kubelet may evict a Pod if an ephemeral container causes the
// Pod to exceed its resource allocation.
//
// To add an ephemeral container, use the ephemeralcontainers subresource of an existing

    - [Promoted Local Ephemeral Storage Capacity Isolation to Stable](#promoted-local-ephemeral-storage-capacity-isolation-to-stable)
    - [Promoted core CSI Migration to Stable](#promoted-core-csi-migration-to-stable)
    - [Promoted CSI Ephemeral Volume to Stable](#promoted-csi-ephemeral-volume-to-stable)

This release does *not* deprecate the v1 HorizontalPodAutoscaler API.

### Generic Ephemeral Volume feature graduates to GA

The generic ephemeral volume feature moved to GA in 1.23.
This feature allows any existing storage driver that supports dynamic provisioning to be used as an ephemeral volume with the volume’s lifecycle bound to the Pod.

### Generic Ephemeral Volumes

### API changes and improvements for ephemeral containers

The API used to create [Ephemeral Containers](https://kubernetes.io/docs/concepts/workloads/pods/ephemeral-containers/) changed in 1.22. The Ephemeral Containers feature is alpha and disabled by default, and the new API does not work with clients that attempt to use the old API.

*   Added pod-level local ephemeral storage metric to the Summary API. Pod-level ephemeral storage reports the total filesystem usage for the containers and emptyDir volumes in the measured Pod. ([#55447](https://github.com/kubernetes/kubernetes/pull/55447),[ @jingxu97](https://github.com/jingxu97))

  * For alpha, volume resizing supports only Gluster volumes.

* [alpha] Provide capacity isolation and resource management for local ephemeral storage

  * You can now set container requests, container limits, and node allocatable reservations for the new `ephemeral-storage` resource.

  * The `ephemeral-storage` resource includes all the disk space a container might consume with container overlay or scratch.

Troubleshoot distroless containers by adding a new container with debugging tools, either in a new copy of the pod or using an ephemeral container. (Ephemeral containers are an alpha feature that are not enabled by default.)
Troubleshoot on a node by creating a container running in the host namespaces and with access to the host’s filesystem.

* a CSI driver that supports ephemeral inline volumes must explicitly declare that by providing a CSIDriver object where the new "mode" field is set to "ephemeral" or "persistent+ephemeral" ([#80568](https://github.com/kubernetes/kubernetes/pull/80568), [@pohly](https://github.com/pohly))

the mountable secrets policy enforced by the ServiceAccount admission plugin when using ephemeral containers. The policy ensures pods running with a service account may only reference secrets specified in the service account's secrets field. Kubernetes clusters are only affected if the ServiceAccount admission plugin and the `kubernetes.io/enforce-mountable-secrets` annotation are used together with ephemeral containers.

**Note**: This only impacts the cluster if the ServiceAccount admission...