* GCE PD volume plugin now supports block volumes. ([#58710](https://github.com/kubernetes/kubernetes/pull/58710), [@screeley44](https://github.com/screeley44))

### External credential provider for client-go

The client-go credential plugins can now be passed in the current cluster information via the `KUBERNETES_EXEC_INFO` environment variable. Learn more about this on [client-go credential plugins documentation](https://docs.k8s.io/reference/access-authn-authz/authentication/#client-go-credential-plugins/).

### CronJob controller v2 is available through feature gate

- Fixed a regression since 1.24 in the scheduling framework when overriding MultiPoint plugins (e.g. default plugins).

   - `DefaultPodTopologySpread` plugin is renamed to `SelectorSpread`.
   - `Unreserve` extension point is removed from Profile definition. All `Reserve`
     plugins implement an `Unreserve` call.
   - `.disablePreemption` was removed. Users can disable preemption by disabling the

                    }
                    final File pluginDir = new File(esDir, "plugins");
                    if (pluginDir.isDirectory()) {
                        settingsBuilder.put("path.plugins", pluginDir.getAbsolutePath());
                    } else {
                        settingsBuilder.put("path.plugins", new File(System.getProperty("user.dir"), "plugins").getAbsolutePath());
                    }

- When a CNI plugin returns dual-stack pod IPs, kubelet will now try to respect the
  "primary IP family" of the cluster by picking a primary pod IP of the same family
  as the (primary) node IP, rather than assuming that the CNI plugin returned the IPs
  in the order the administrator wanted (since some CNI plugins don't allow

For the 1.9 release, SIG Storage made Kubernetes more pluggable and modular by introducing an alpha implementation of the Container Storage Interface (CSI). CSI will make installing new volume plugins as easy as deploying a pod, and enable third-party storage providers to develop their plugins without the need to add code to the core Kubernetes codebase.

        getProject(f2);
    }

    @Disabled("Maven 4 does not allow duplicate plugin declarations")
    @Test
    void testDuplicatePluginDefinitionsMerged() throws Exception {
        File f1 = getTestFile("src/test/resources/projects/duplicate-plugins-merged-pom.xml");

        MavenProject project = getProject(f1);

- kube-apiserver: When using `--enable-admission-plugins` the `Priority` admission plugin is now enabled by default (matching changes in 1.11.1+). If using `--admission-control` to fully specify the set of admission plugins, it is now necessary to add the `Priority` admission plugin for the PodPriority feature to work properly. ([#65739](https://github.com/kubernetes/kubernetes/pull/65739), [@liggitt](https://github.com/liggitt))...

* Added support to a hierarchy of kubectl plugins (a tree of plugins as children of other plugins). ([#45981](https://github.com/kubernetes/kubernetes/pull/45981), [@fabianofranz](https://github.com/fabianofranz))
    * Added exported env vars to kubectl plugins so that plugin developers have access to global flags, namespace, the plugin descriptor and the full path to the caller binary.