- Kubeadm: add the deprecated flag --port=0 to kube-controller-manager and kube-scheduler manifests to disable insecure serving. Without this flag the components by default serve (e.g. /metrics) insecurely on the default node interface (controlled by --address). Users that wish to override this behavior and enable insecure serving can pass...

  - The deprecated `--etcd-quorum-read` flag has been removed. Quorum reads are now always enabled when fetching data from etcd. Remove the `--etcd-quorum-read` flag from kube-apiserver invocations before upgrading.
- kube-controller-manager
  - The deprecated `--insecure-experimental-approve-all-kubelet-csrs-for-group` flag has been removed.
- kubelet

  - The deprecated --storage-versions flag has been removed. The storage versions will always be the default value built-in the kube-apiserver binary. ([#67678](https://github.com/kubernetes/kubernetes/pull/67678), [@caesarxuchao](https://github.com/caesarxuchao))

#### Network

- The deprecated flag `--conntrack-max` has been removed from kube-proxy. Users of this flag should switch to `--conntrack-min` and `--conntrack-max-per-core` instead. ([#78399](https://github.com/kubernetes/kubernetes/pull/78399), [@rikatz](https://github.com/rikatz))

  - the `--cloud-provider-gce-lb-src-cidrs` flag has been deprecated. This flag will be removed once the GCE Cloud Provider is removed from kube-apiserver. ([#81094](https://github.com/kubernetes/kubernetes/pull/81094), [@andrewsykim](https://github.com/andrewsykim))

StreamingProxyRedirects feature and `--redirect-container-streaming` flag are deprecated, and will be removed in a future release. The default behavior (proxy streaming requests through the kubelet) will be the only supported option. If you are setting `--redirect-container-streaming=true`, then you must migrate off this configuration. The flag will no longer be able to be enabled starting in v1.20. If you are not setting the flag, no action is necessary. ([#88290](https://github.com/kubernetes/ku...

     `--horizontal-pod-autoscaler-use-rest-clients` flag to `true`.

   - In version 1.9, this behavior will be enabled by default, and must be explicitly
     disabled by setting the `--horizontal-pod-autoscaler-use-rest-clients` flag to `false`.

### Cluster Lifecycle

- The `auto-detect` behavior of the kubelet's `--cloud-provider` flag is deprecated.

### **Node**

*   The kubelet `--network-plugin-dir` flag is removed. This flag was deprecated in version 1.7, and is replaced with `--cni-bin-dir`. ([#53564](https://github.com/kubernetes/kubernetes/pull/53564),[ @supereagle](https://github.com/supereagle))

  the normal deletion flow, so cluster breaking consequences apply. ([#127513](https://github.com/kubernetes/kubernetes/pull/127513), [@tkashem](https://github.com/tkashem)) [SIG API Machinery, Etcd, Node and Testing]

- The new flag `--chunk-size=SIZE` for `kubectl drain` has been promoted to beta, and enabled by default. This flag  may be used to alter the number of items or disable this feature when `0` is passed. ([#100148](https://github.com/kubernetes/kubernetes/pull/100148), [@KnVerey](https://github.com/KnVerey))