kubeadm, the cluster lifecycle building block, continues to receive features and stability work required for bootstrapping production clusters efficiently. kubeadm has promoted high availability (HA) capability to beta, allowing users to use the familiar `kubeadm init` and `kubeadm join` commands to [configure and deploy an HA control plane](https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/high-availability/). An entire new test suite has been created specifically for ensuring...

- 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))

  It changes the dual-stack API wrt Service from a single ipFamily field to 3
  fields: ipFamilyPolicy (SingleStack, PreferDualStack, RequireDualStack),
  ipFamilies (a list of families assigned), and clusterIPs (inclusive of
  clusterIP).  Most users do not need to set anything at all, defaulting will
  handle it for them.  Services are single-stack unless the user asks for

- The `--bind-address` parameter in kube-proxy is misleading, no port is opened with this address. Instead it is translated internally to "nodeIP". The nodeIPs for both families are now taken from the Node object if `--bind-address` is unspecified or set to the "any" address (0.0.0.0 or ::). It is recommended to leave `--bind-address` unspecified, and in particular avoid to set it to localhost (127.0.0.1 or ::1) ([#1195...

- Kube-proxy will now warn at startup if the configuration seems inconsistent
  with respect to IP families. (For example, if you have an IPv4 node IP, but
  `--cluster-cidr` is IPv6.) ([#119003](https://github.com/kubernetes/kubernetes/pull/119003), [@danwinship](https://github.com/danwinship)) [SIG Network]