### Feature

- Add option to enable leader election in local-up-cluster.sh via the LEADER_ELECT cli flag. ([#127786](https://github.com/kubernetes/kubernetes/pull/127786), [@Jefftree](https://github.com/Jefftree)) [SIG API Machinery]

* Use separate client for leader election in scheduler to avoid starving leader election by regular scheduler operations. ([#53793](https://github.com/kubernetes/kubernetes/pull/53793), [@wojtek-t](https://github.com/wojtek-t))

* Updated priority of mirror pod according to PriorityClassName. ([#58485](https://github.com/kubernetes/kubernetes/pull/58485), [@k82cn](https://github.com/k82cn))

* kube-scheduler: restores default leader election behavior. Setting the `--leader-elect`  command line parameter to `true` ([#60524](https://github.com/kubernetes/kubernetes/pull/60524), [@dims](https://github.com/dims))

- kubeadm: fixed ignoring errors when pulling control plane images ([#80529](https://github.com/kubernetes/kubernetes/pull/80529), [@bart0sh](https://github.com/bart0sh))
- Fix a bug in kube-addon-manager's leader election logic that made all replicas active. ([#80575](https://github.com/kubernetes/kubernetes/pull/80575), [@mborsz](https://github.com/mborsz))

* kube-scheduler: restores default leader election behavior. leader-elect command line parameter should "true" ([#60524](https://github.com/kubernetes/kubernetes/pull/60524), [@dims](https://github.com/dims))

- Kubernetes components that perform leader election now only support using `Leases` for this. ([#114055](https://github.com/kubernetes/kubernetes/pull/114055), [@aimuz](https://github.com/aimuz))

- Updated the default API priority-and-fairness config to avoid endpoint/configmaps operations from controller-manager to all match leader-election priority level. ([#106725](https://github.com/kubernetes/kubernetes/pull/106725), [@wojtek-t](https://github.com/wojtek-t))

- Support more than 100 disk mounts on Windows (#105673, @andyzhangx) [SIG Storage and Windows]
- The --leader-elect* CLI args are now honored correctly in scheduler. (#106130, @Huang-Wei) [SIG Scheduling]
- The kube-proxy sync_proxy_rules_iptables_total metric now gives
  the correct number of rules, rather than being off by one.
  

- Client-go: Optimized leaders renewing leases by updating leader lock optimistically without getting the record from the API server first. Also, a new metric `leader_election_slowpath_total` was added to allow users to monitor how many leader elections are updated non-optimistically.

- Added Coordinated Leader Election as Alpha under the `CoordinatedLeaderElection` feature gate. With the feature enabled, the control plane can use LeaseCandidate objects (coordination.k8s.io/v1alpha1 API group) to participate in a leader election and let the kube-apiserver select the best instance according to some strategy. ([#124012](https://github.com/kubernetes/kubernetes/pull/124012),...