For more information, see [#53288](https://issue.k8s.io/53288).

* `kubeadm init` and `kubeadm join` invocations on newly installed systems can encounter a `/var/lib/kubelet is not empty` message during pre-flight checks that prevents setup. If this is the only pre-flight failure, it can be safely ignored with `--skip-preflight-checks`.

For more information, see [#53356](https://issue.k8s.io/53356#issuecomment-333748618).

- Kubeadm: perform pre-flight validation on host/node name upon `kubeadm init` and `kubeadm join`, showing warnings on non-compliant names ([#99194](https://github.com/kubernetes/kubernetes/pull/99194), [@pacoxu](https://github.com/pacoxu))

- The kube-proxy `sync_proxy_rules_iptables_total` metric has now reverted back
  to its pre-1.27 behavior of tracking the total number of iptables rules that
  kube-proxy is responsible for, rather than only counting the number of rules
  that it re-synced on the last sync. The new `sync_proxy_rules_iptables_last`

### (No, really, you MUST read this before you upgrade)

- Audit log files are now created with a mode of 0600. Existing file permissions will not be changed. If you need the audit file to be readable by a non-root user, you can pre-create the file with the desired permissions. ([#95387](https://github.com/kubernetes/kubernetes/pull/95387), [@JAORMX](https://github.com/JAORMX)) [SIG API Machinery and Auth]

- Kubectl: restores `--dry-run`, `--dry-run=true`, and `--dry-run=false` for compatibility with pre-1.23 invocations. ([#107021](https://github.com/kubernetes/kubernetes/pull/107021), [@liggitt](https://github.com/liggitt)) [SIG CLI and Testing]

## Changes by Kind

### Deprecation

- Kubectl: restored `--dry-run`, `--dry-run=true`, and `--dry-run=false` for compatibility with pre-1.23 invocations. ([#107003](https://github.com/kubernetes/kubernetes/pull/107003), [@julianvmodesto](https://github.com/julianvmodesto))

   ([#123413](https://github.com/kubernetes/kubernetes/pull/123413), [@seans3](https://github.com/seans3))
- A new flag called `custom` has been introduced in `kubectl debug`, allowing users to customize pre-defined profiles. ([#120346](https://github.com/kubernetes/kubernetes/pull/120346), [@ardaguclu](https://github.com/ardaguclu))

- Scheduler: in 1.29 pre-releases, enabling contextual logging slowed down pod scheduling. ([#121715](https://github.com/kubernetes/kubernetes/pull/121715), [@pohly](https://github.com/pohly)) [SIG Instrumentation and Scheduling]

- Kubeadm: added the "--cleanup-tmp-dir" flag for `kubeadm reset`. It will cleanup the contents of `/etc/kubernetes/tmp`. The...