- The JWT authenticator configuration set via the `--authentication-config` flag is now dynamically reloaded as the file changes on disk. ([#123525](https://github.com/kubernetes/kubernetes/pull/123525), [@enj](https://github.com/enj))

### Secrets
* Populate environment variables from a secrets. ([#39446](https://github.com/kubernetes/kubernetes/pull/39446), [@fraenkel](https://github.com/fraenkel))
* Added a new secret type "bootstrap.kubernetes.io/token" for dynamically creating TLS bootstrapping bearer tokens. ([#41281](https://github.com/kubernetes/kubernetes/pull/41281), [@ericchiang](https://github.com/ericchiang))

### Service

* Fix an issue that pods using hostNetwork keep increasing. ([#67456](https://github.com/kubernetes/kubernetes/pull/67456), [@Huang-Wei](https://github.com/Huang-Wei))
* Allows extension API server to dynamically discover the requestheader CA certificate when the core API server doesn't use certificate based authentication for it's clients ([#66394](https://github.com/kubernetes/kubernetes/pull/66394), [@rtripat](https://github.com/rtripat))

                          type: string
                        derivePort:
                          description: |-
                            On a redirect, dynamically set the port: * FROM_PROTOCOL_DEFAULT: automatically set to 80 for HTTP and 443 for HTTPS.

                            Valid Options: FROM_PROTOCOL_DEFAULT, FROM_REQUEST_PORT
                          enum:

  configuring this). ([#97979](https://github.com/kubernetes/kubernetes/pull/97979), [@danwinship](https://github.com/danwinship)) [SIG Network and Node]

As a special exception to the GNU Lesser General Public License version 3
("LGPL3"), the copyright holders of this Library give you permission to
convey to a third party a Combined Work that links statically or dynamically
to this Library without providing any Minimal Corresponding Source or
Minimal Application Code as set out in 4d or providing the installation
information set out in section 4e, provided that you comply with the other

higher-dimensional objects.
With arrays of arrays, the inner arrays are, by construction, always the same length;
however with slices of slices (or arrays of slices), the inner lengths may vary dynamically.
Moreover, the inner slices must be initialized individually.
</p>

<h3 id="Struct_types">Struct types</h3>

<p>
A struct is a sequence of named elements, called fields, each of which has a

- Kube-aggregator certificates are dynamically loaded on change from disk ([#92791](https://github.com/kubernetes/kubernetes/pull/92791), [@p0lyn0mial](https://github.com/p0lyn0mial)) [SIG API Machinery]

higher-dimensional objects.
With arrays of arrays, the inner arrays are, by construction, always the same length;
however with slices of slices (or arrays of slices), the inner lengths may vary dynamically.
Moreover, the inner slices must be initialized individually.
</p>

<h3 id="Struct_types">Struct types</h3>

<p>
A struct is a sequence of named elements, called fields, each of which has a

- Kube-aggregator certificates are dynamically loaded on change from disk ([#92791](https://github.com/kubernetes/kubernetes/pull/92791), [@p0lyn0mial](https://github.com/p0lyn0mial)) [SIG API Machinery]