ull/59883), [@kow3ns](https://github.com/kow3ns))

* MountPropagation feature is now beta. As a consequence, all volume mounts in containers are now `rslave` on Linux by default. To make this default work in all Linux environments the entire mount tree should be marked as shareable, e.g. via `mount --make-rshared /`. All Linux distributions that use systemd already have the root directory mounted as rshared and hence they need not do anything. In Linux environments without systemd we...

- Kubelet TCP and HTTP probes are now more effective using networking resources:
  conntrack entries, sockets. This is achieved by reducing the `TIME-WAIT` state
  of the connection to 1 second, instead of the defaults 60 seconds. This allows
  kubelet to free the socket, and free conntrack entry and ephemeral port associated. ([#115143](https://github.com/kubernetes/kubernetes/pull/115143), [@aojea](https://github.com/aojea))

- Ensure all vSphere nodes are are tracked by volume attach-detach controller ([#96689](https://github.com/kubernetes/kubernetes/pull/96689), [@gnufied](https://github.com/gnufied))
- Ensure empty string annotations are copied over in rollbacks. ([#94858](https://github.com/kubernetes/kubernetes/pull/94858), [@waynepeking348](https://github.com/waynepeking348))

- Kubenet: added HostPort IPv6 support.  HostPortManager: operates only with one IP family, failing if receives port mapping entries with different IP families.  HostPortSyncer: operates only with one IP family, skipping portmap entries with different IP families ([#80854](https://github.com/kubernetes/kubernetes/pull/80854), [@aojea](https://github.com/aojea))

- Client-go now exposes two new metrics to monitor the client-go logic that
  generate http.Transports for the clients.
  
  - `rest_client_transport_cache_entries` is a gauge metric
  with the number of existing entries in the internal cache
  
  - `rest_client_transport_create_calls_total` is a counter
  that increments each time a new transport is created, storing

* Ensure IP is set for Azure internal load balancer. ([#59083](https://github.com/kubernetes/kubernetes/pull/59083), [@feiskyer](https://github.com/feiskyer))

* If a required flag is not provided to a command, the user will only see the required flag error message, instead of the entire usage menu. ([#86693](https://github.com/kubernetes/kubernetes/pull/86693), [@sallyom](https://github.com/sallyom))

https://git.k8s.io/community/contributors/devel/sig-release/release.md#issuepr-kind-label
3. Ensure you have added or ran the appropriate tests for your PR: https://git.k8s.io/community/contributors/devel/sig-testing/testing.md

* kubeadm - Ensure the peer port is secured by explicitly setting the peer URLs for the default etcd instance. ([#64988](https://github.com/kubernetes/kubernetes/pull/64988), [@detiber](https://github.com/detiber))
    * kubeadm - Ensure that the etcd certificates are generated using a proper CN

* Kubernetes 1.12 also enables [Kubelet device plugin registration](https://github.com/kubernetes/enhancements/issues/595) feature by default. Before upgrading to 1.12, ensure the `driver-registrar` CSI sidecar container for your CSI driver is configured to handle...