* Allow Secret & ConfigMap keys to contain caps, dots, and underscores ([#25458](https://github.com/kubernetes/kubernetes/pull/25458), [@errm](https://github.com/errm))

- kube-proxy: os exit when CleanupAndExit is set to true ([#76732](https://github.com/kubernetes/kubernetes/pull/76732), [@JieJhih](https://github.com/JieJhih))
- Kubernetes will now allow trailing dots in the externalName of Services of type ExternalName. ([#78385](https://github.com/kubernetes/kubernetes/pull/78385), [@thz](https://github.com/thz))

### Node

### Node Components
* Kubelet config should ignore file start with dots.
  ([#39196](https://github.com/kubernetes/kubernetes/pull/39196), [@resouer](https://github.com/resouer))
* Bump GCI to gci-stable-56-9000-84-2.
  ([#41819](https://github.com/kubernetes/kubernetes/pull/41819),

  * Fix a bug where Kubelet does not ignore pod manifest files starting with dots ([#45111](https://github.com/kubernetes/kubernetes/pull/45111), [@dwradcliffe](https://github.com/dwradcliffe))

dog
dojin.com
domains
donetsk.ua
dongnai.vn
dongthap.vn
donna.no
dontexist.com
dontexist.net
dontexist.org
doomdns.com
doomdns.org
dopaas.com
doshi.yamanashi.jp
dot
dovre.no
download
dp.ua
dr.in
dr.tr
drammen.no
drangedal.no
dray-dns.de
drayddns.com
draydns.de
dreamhosters.com
drive
drobak.no
drr.ac
drud.io
drud.us

- `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`,

enabled.([#51436](https://github.com/kubernetes/kubernetes/pull/51436))

* [Action required] The validation rule for metadata.initializers.pending[x].name is tightened. The initializer name must contain at least three segments, separated by dots. You can create objects with pending initializers and not rely on the API server to add pending initializers according to `initializerConfiguration`. If you do so, update the initializer name in the existing objects and the configuration files to comply...

- Allow for Pod search domains to be a single dot `.` or contain an underscore `_` ([#127167](https://github.com/kubernetes/kubernetes/pull/127167), [@adrianmoisey](https://github.com/adrianmoisey)) [SIG Apps, Network and Testing]

- Promoted `RelaxedDNSSearchValidation` to beta, allowing for Pod search domains to be a single dot "." or contain an underscore "_". ([#130128](https://github.com/kubernetes/kubernetes/pull/130128), [@adrianmoisey](https://github.com/adrianmoisey)) [SIG Apps and Network]

- Graduated relaxed DNS search string validation to GA. For the Pod API, `.spec.dnsConfig.searches`
  now allows an underscore (`_`) where a dash (`-`) would be allowed, and it allows search strings be a single dot `.`. ([#132036](https://github.com/kubernetes/kubernetes/pull/132036), [@adrianmoisey](https://github.com/adrianmoisey)) [SIG Network and Testing]