- [<code>CSIMigrationvSphere</code> feature gate has not migrated to new CRD APIs](#csimigrationvsphere-feature-gate-has-not-migrated-to-new-crd-apis)
    - [Workloads that saturate nodes with pods may see pods that fail due to node admission](#workloads-that-saturate-nodes-with-pods-may-see-pods-that-fail-due-to-node-admission)
    - [Etcd v3.5.[0-2] data corruption](#etcd-v350-2-data-corruption)
  - [Urgent Upgrade Notes](#urgent-upgrade-notes)

- e2e tests that require SSH may now be used against clusters that have nodes without external IP addresses by setting the environment variable `KUBE_SSH_BASTION` to the `host:port` of a machine that is allowed to SSH to those nodes.  The same private key that the test would use is used for the bastion host.  The test connects to the bastion and then tunnels another SSH connection to...

external etcd endpoints passed in the `ClusterConfiguration` that have Unicode characters are no longer IDNA encoded (converted to Punycode). They are now just URL encoded as per Go's implementation of RFC-3986, have duplicate "/" removed from the URL paths, and passed like that directly to the `kube-apiserver` `--etcd-servers` flag. If you have etcd endpoints that have Unicode characters, it is advisable to encode them in advance with tooling that is fully IDNA compliant. If you don't do that, the Go standard...

*   A new controller automatically cleans up Certificate Signing Requests that are Approved and Issued, or Denied. ([#51840](https://github.com/kubernetes...

**[Pod priority and preemption](https://kubernetes.io/docs/concepts/configuration/pod-priority-preemption/) is now enabled by default.** Note that this means that pods from *any* namespace can now request priority classes that compete with and/or cause preemption of critical system pods that are already running. If that is not desired, disable the PodPriority feature by setting `--feature-gates=PodPriority=false` on the kube-apiserver, kube-scheduler, and kubelet components before upgrading to 1.11....

	any NetworkPolicy whose spec.podSelector targets them. Pods that are
	targeted by NetworkPolicies accept traffic that is accepted by any of
	the NetworkPolicies (and nothing else), and pods that are not targeted
	by any NetworkPolicy accept all traffic by default.
	Action Required:
	When upgrading to Kubernetes 1.7 (and a network plugin that supports
	the new NetworkPolicy v1 semantics), to ensure full behavioral

  network plugins which was first widely noticed in 1.16 (though some users saw it
  earlier than that, possibly only with specific network plugins). If you were previously
  using ethtool to disable checksum offload on your primary network interface, you should
  now be able to stop doing that. ([#92035](https://github.com/kubernetes/kubernetes/pull/92035), [@danwinship](https://github.com/danwinship)) [SIG Network and Node]

SIG Node focused on stability and performance improvements in the 1.13 release.  A new alpha feature is introduced to improve the mechanism that nodes heartbeat back to the control plane.  The `NodeLease` feature results in the node using a `Lease` resource in the `kube-node-lease` namespace that is renewed periodically.  The `NodeStatus` that was used previously to heartbeat back to the control plane is only updated when it changes.  This reduces load on the control plane for large clusters....

### Storage

- It introduces a new scope name `VolumeAttributesClass`. 
  
  It matches all PVC objects that have the volume attributes class mentioned.