// Defaults to false.
  // +optional
  optional bool stdin = 1;

  // Stdout if true indicates that stdout is to be redirected for the attach call.
  // Defaults to true.
  // +optional
  optional bool stdout = 2;

  // Stderr if true indicates that stderr is to be redirected for the attach call.
  // Defaults to true.
  // +optional
  optional bool stderr = 3;

  - The command `kubeadm config print-defaults` is deprecated in favor of `kubeadm config print init-defaults` and `kubeadm config print join-defaults` ([#69617](https://github.com/kubernetes/kubernetes/pull/69617), [@rosti](https://github.com/rosti))

#### Defaults

 - The default spec.updateStrategy for the StatefulSet and DaemonSet kinds is
 RollingUpdate for the apps/v1beta2 group version. You can explicitly set
 the OnDelete strategy, and no strategy auto-conversion is applied to
 replace default values.

 - As mentioned in [Behavioral Changes](#behavioral-changes), selector
 defaults are disabled.

    *   Clients using older endpoints will be unaffected. This change is only at the REST API level and is independent of the default behavior of particular clients (e.g. this does not affect the default for the kubectl `--cascade` flag).
    *   If you upgrade your client-go libs and use the `AppsV1()` interface, please note that the default garbage collection behavior is changed.

### **Auth**

#### **Audit**

* Pod priority and preemption is now enabled by default. Even if you don't plan to use this feature, you might need to take some action immediately after upgrading. In multi-tenant clusters where not all users are trusted, you are advised to create appropriate quotas for two default priority classes, system-cluster-critical and system-node-critical, which are added to clusters by default. `ResourceQuota` should be created to limit users from creating Pods at these priorities...

* The alpha `Initializers` admission plugin is no longer enabled by default. This matches the off-by-default behavior of the alpha API which drives initializer behavior. ([#66039](https://github.com/kubernetes/kubernetes/pull/66039), [@liggitt](https://github.com/liggitt))
* kubeadm: Default component configs are printable via kubeadm config print-default ([#66074](https://github.com/kubernetes/kubernetes/pull/66074), [@rosti](https://github.com/rosti))

    * ServiceDelimiter string Delimiter to use to separate overridden services (multiple services) Defaults to "&"
    * ServicenameDelimiter string Delimiter to use to separate servicename from its configuration parameters Defaults "|"
    * OverrideSeparator string Delimiter to use to separate region of occurrence, url and signing region for each override Defaults to ","

- Feature gates CSIMigration to Beta (on by default) and CSIMigrationGCE to Beta (off by default since it requires installation of the GCE PD CSI Driver) ([#85231](https://github.com/kubernete...

- Updated `kube-openapi` to remove invalid defaults: OpenAPI spec no longer includes default of `{}` for certain fields where it did not make sense. ([#120757](https://github.com/kubernetes/kubernetes/pull/120757), [@alexzielenski](https://github.com/alexzielenski))

- CRDs: For structural schemas, non-nullable null map fields will now be dropped and defaulted if a default is available. null items in the list will continue being preserved, and fail validation if not nullable. ([#95423](https://github.com/kubernetes/kubernetes/pull/95423), [@apelisse](https://github.com/apelisse)) [SIG API Machinery]