What’s New in Kubernetes 1.23? Top Features You Can Use Today

Kubernetes 1.23 GA introduces over 45 enhancements, with 15 promoted to stable and 19 brand‑new. The most immediately usable stable features are IPv4/IPv6 dual‑stack, CronJobs, Ephemeral volumes and the v2 Horizontal Pod Autoscaler (HPA) API.

IPv4/IPv6 Dual‑Stack Support

The .spec.ipFamilyPolicy field can be set to SingleStack, PreferDualStack or RequireDualStack. Setting it to PreferDualStack or RequireDualStack enables pods and services to receive both IPv4 and IPv6 addresses and activates dual‑stack outbound routing.

CronJobs

CronJobs allow periodic tasks in a cluster, mirroring Linux cron. An example manifest runs a job every ten minutes that prints “Hello Newstack”:

apiVersion: batch/v1
kind: CronJob
metadata:
  name: hello
spec:
  schedule: "*/10 * * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: hello
            image: busybox
            imagePullPolicy: IfNotPresent
            command: ["/bin/sh","-c","date; echo Hello Newstack"]
          restartPolicy: OnFailure

Ephemeral Volumes

Since 1.19, four types of ephemeral volumes are supported: emptyDir, configMap/secret, CSI‑based volumes, and generic volumes provided by any storage driver. An example pod uses a CSI driver:

kind: Pod
apiVersion: v1
metadata:
  name: sample-storage-app
spec:
  containers:
  - name: storage-frontend
    image: busybox
    volumeMounts:
    - mountPath: "/storage"
      name: sample-storage-app-vol
    command: ["sleep","1000000"]
  volumes:
  - name: sample-storage-app-vol
    csi:
      driver: inline.storage.kubernetes.io
      volumeAttributes: {}

HPA API v2

The Horizontal Pod Autoscaler now supports metric types: resource usage, custom metrics, and external metrics. The controller loop runs every 15 seconds (default) and scales pods based on the defined metrics.

Deprecated and Beta Features

Three APIs are deprecated in 1.23: HPA v2beta2, FlexVolume, and the klog flag. Two features graduate to beta: PodSecurity (replacing PodSecurityPolicy) and structured logging with JSON output.

Alpha Features

New alpha‑stage capabilities include CEL‑based CRD validation, server‑side field validation warnings, and OpenAPI v3 generation for all Kubernetes types.

For a complete list of changes, refer to the official release notes.