* Add MAX_PODS_PER_NODE env so that GCE/GKE user can use it to specify the default max pods per node for the cluster. IP_ALIAS_SIZE will be changed accordingly. Must have ip alias enabled. ([#63451](https://github.com/kubernetes/kubernetes/pull/63451), [@grayluck](https://github.com/grayluck))

## Changelog since v1.8.12

### Other notable changes

* Add MAX_PODS_PER_NODE env so that user can use it to specify the default max pods per node for the cluster. IP_ALIAS_SIZE will be changed accordingly. Must have ip alias enabled. ([#63466](https://github.com/kubernetes/kubernetes/pull/63466), [@grayluck](https://github.com/grayluck))

* Add MAX_PODS_PER_NODE env so that GCE/GKE user can use it to specify the default max pods per node for the cluster. IP_ALIAS_SIZE will be changed accordingly. Must have ip alias enabled. ([#63621](https://github.com/kubernetes/kubernetes/pull/63621), [@grayluck](https://github.com/grayluck))

- 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))

- Fixes a bug of identifying the correct containerd process. ([#97888](https://github.com/kubernetes/kubernetes/pull/97888), [@pacoxu](https://github.com/pacoxu))
- Fixes add-on manager leader election to use leases instead of endpoints, similar to what kube-controller-manager does in 1.20 ([#98968](https://github.com/kubernetes/kubernetes/pull/98968), [@liggitt](https://github.com/liggitt))

* Remove deprecated kubectl command aliases 'run-container' ([#70728](https://github.com/kubernetes/kubernetes/pull/70728), [@Pingan2017](https://github.com/Pingan2017))

  name of controllers that can be turned on/off that are passed to the `--controllers`
  flag (e.g., `pod-garbage-collector-controller`). The old names (eg `podgc`) are
  also accepted and aliased to the new names. ([#115813](https://github.com/kubernetes/kubernetes/pull/115813), [@atiratree](https://github.com/atiratree))
- `kubeadm`: Introduced a new feature gate `UpgradeAddonsBeforeControlPlane` to

### Bug or Regression

- Avoid GCE API calls when initializing GCE CloudProvider for Kubelets.
  Avoid unnecessary GCE API calls when adding IP alises or reflecting them in Node object in GCE cloud provider. ([#96864](https://github.com/kubernetes/kubernetes/pull/96864), [@tosi3k](https://github.com/tosi3k)) [SIG Apps, Cloud Provider and Network]

### Bug or Regression

- Avoid GCE API calls when initializing GCE CloudProvider for Kubelets.
  Avoid unnecessary GCE API calls when adding IP alises or reflecting them in Node object in GCE cloud provider. ([#96863](https://github.com/kubernetes/kubernetes/pull/96863), [@tosi3k](https://github.com/tosi3k)) [SIG Apps, Cloud Provider and Network]

* The Categories []string field on discovered API resources represents the list of group aliases (e.g. "all") that each resource belongs to. ([#43338](https://github.com/kubernetes/kubernetes/pull/43338), [@fabianofranz](https://github.com/fabianofranz))