- Kubeadm: the deprecated kube-dns is no longer supported as an option. If "ClusterConfiguration.dns.type" is set to "kube-dns" kubeadm will now throw an error. ([#99646](https://github.com/kubernetes/kubernetes/pull/99646), [@rajansandeep](https://github.com/rajansandeep)) [SIG Cluster Lifecycle]

- `StatefulSet` names must be DNS labels, rather than subdomains. Any `StatefulSet`
  which took advantage of subdomain validation (by having dots in the name) can't
  possibly have worked, because we eventually set `pod.spec.hostname` from the `StatefulSetName`,

 * that makes `java.net.URL` unusable for many things. It shouldn't be used as a [Map] key or in a
 * [Set]. Doing so is both inefficient because equality may require a DNS lookup, and incorrect
 * because unequal URLs may be equal because of how they are hosted.
 *
 * ### Equal URLs should be equal
 *
 * These two URLs are semantically identical, but `java.net.URI` disagrees:
 *

- Fixes a regression introduced in 1.29 where conntrack entries for UDP connections
  to deleted pods did not get cleaned up correctly, which could (among other things)
  cause DNS problems when DNS pods were restarted. ([#127807](https://github.com/kubernetes/kubernetes/pull/127807), [@danwinship](https://github.com/danwinship)) [SIG Network]

- Fix the bug PIP's DNS is deleted if no DNS label service annotation isn't set. ([#87311](https://github.com/kubernetes/kubernetes/pull/87311), [@nilo19](https://github.com/nilo19)) [SIG Cloud Provider]

    )
  }

  @Test
  fun invalidHost() {
    // Note that 1234.1.1.1 is an invalid host in a URI, but URL isn't as strict.
    client =
      client
        .newBuilder()
        .dns(FakeDns())
        .build()
    assertFailsWith<UnknownHostException> {
      getResponse(
        Request
          .Builder()
          .url("http://1234.1.1.1/index.html".toHttpUrl())
          .build(),

- Resolved a bug where DaemonSet updates unnecessarily triggered duplicate validation due to overlapping calls to `ValidateDaemonSet` and ValidateDaemonSetUpdate. This redundancy has been removed to prevent repeated validation runs. ([#132548](https://github.com/kubernetes/kubernetes/pull/132548), [@gavinkflam](https://github.com/gavinkflam))

- Kubeadm: during 'upgrade apply', if the kube-proxy ConfigMap is missing, assume that kube-proxy should not be upgraded. Same applies to a missing kube-dns/coredns ConfigMap for the DNS server addon. Note that this is a temporary workaround until 'upgrade apply' supports phases. Once phases are supported the kube-proxy/dns upgrade should be skipped manually. ([#89593](https://github.com/kubernetes/kubernetes/pull/89593), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]...

      .assertNoMoreLogs()
  }

  @Test
  fun connectFail() {
    setLevel(Level.BASIC)
    client =
      OkHttpClient
        .Builder()
        .dns { hostname: String? -> throw UnknownHostException("reason") }
        .addInterceptor(applicationInterceptor)
        .build()
    try {
      client.newCall(request().build()).execute()
      fail<Any>()

   *     underlying this step or, if {@code get()} throws a different kind of exception, that
   *     exception itself.
   * @param executor the executor that runs {@code fallback} if the input fails
   */
  public <X extends Throwable> ClosingFuture<V> catching(
      Class<X> exceptionType, ClosingFunction<? super X, ? extends V> fallback, Executor executor) {