* 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. ([#96863](https://github.com/kubernetes/kubernetes/pull/96863), [@tosi3k](https://github.com/tosi3k)) [SIG Apps, Cloud Provider and Network]

    
    From: [@mikedanese](https://github.com/mikedanese):
    Instead of aliasing. Aliases are annoying in a number of ways. This is
    specifically bugging me now because they make the action graph harder to
    analyze programmatically. By using aliases here, we would need to handle
    potentially aliased go_binary targets and dereference to the effective
    target.
  

#### Apps

- Hyperkube short aliases have been removed from source code, because hyperkube docker image currently creates these aliases. ([#76953](https://github.com/kubernetes/kubernetes/pull/76953), [@Rand01ph](https://github.com/Rand01ph))

#### Auth