- Fixed SELinux warning controller not to emit events for completed pods. ([#136098](https://github.com/kubernetes/kubernetes/pull/136098), [@jsafrane](https://github.com/jsafrane)) [SIG Apps, Storage and Testing]

- Added warnings when creating headless service with set `loadBalancerIP`,`externalIPs` and/or `SessionAffinity`. ([#132214](https://github.com/kubernetes/kubernetes/pull/132214), [@Peac36](https://github.com/Peac36))

  - The `--experimental-encryption-provider-config` flag is deprecated in favor of `--encryption-provider-config`. The old flag is accepted with a warning but will be removed in 1.14. ([#71206](https://github.com/kubernetes/kubernetes/pull/71206),...

- Added warnings for overlap paths in ConfigMap, Secret, DownwardAPI, Projected. Added warning for cases when ProjectedVolume with sources is provided. ([#121968](https://github.com/kubernetes/kubernetes/pull/121968), [@Peac36](https://github.com/Peac36))

- 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))

## Changes by Kind

### Deprecation

- Added a [warning](https://k8s.io/blog/2020/09/03/warnings/) response when handling requests that set the deprecated `spec.externalID` field for a Node. ([#115944](https://github.com/kubernetes/kubernetes/pull/115944), [@SataQiu](https://github.com/SataQiu)) [SIG Node]
- Added warnings to the Services API. Kubernetes now warns for Services in the case of:

  as deprecated and print a warning if it is used directly; it will be removed in
  a future release. Add a replacement sub-phase ''enable-client-cert-rotation''.' ([#124419](https://github.com/kubernetes/kubernetes/pull/124419), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

- Fixed race-condition in service allocation logic which leads to spurious IPAddressWrongReference warnings impacting performance ([#133954](https://github.com/kubernetes/kubernetes/pull/133954), [@aroradaman](https://github.com/aroradaman)) [SIG Network]

    assert not override4 or "x-level4" in response.headers
    assert not override5 or "x-level5" in response.headers


def test_openapi():
    client = TestClient(app)
    with warnings.catch_warnings(record=True) as w:
        warnings.simplefilter("always")
        response = client.get("/openapi.json")
        assert issubclass(w[-1].category, UserWarning)
        assert "Duplicate Operation ID" in str(w[-1].message)

- Kubeadm: improve the strict parsing of user YAML/JSON configuration files. Next to printing warnings for unknown and duplicate fields (current state), also print warnings for fields with incorrect case sensitivity - e.g. `controlPlaneEndpoint` (valid), `ControlPlaneEndpoint` (invalid). Instead of only printing warnings during `init` and `join` also print warnings when downloading the ClusterConfiguration, KubeletConfiguration or KubeProxyConfiguration objects from the cluster....