([#123341](https://github.com/kubernetes/kubernetes/pull/123341), [@neolit123](https://github.com/neolit123))
- kubectl `port-forward` over websockets (tunneling SPDY) can now be enabled using an `Alpha` feature flag environment variable: KUBECTL_PORT_FORWARD_WEBSOCKETS=true. The API Server being communicated to must *also* have an `Alpha` feature flag enabled: PortForwardWebsockets.

      You can safely roll back from 1.4 to 1.3, and things with init-containers
      will still work (pods, deployments, etc).
    * If you are running 1.3, only use the alpha annotation, or it may be lost when
      rolling forward.
      The status has moved from annotation key
      `pods.beta.kubernetes.io/init-container-statuses` to
      `pods.beta.kubernetes.io/init-container-statuses`.