- When using `kubectl logs <pod-name>` and the pod is not found, the error message now includes the namespace. Previously, the message would be "Error from server (NotFound): pods "my-pod-name" not found". Now, it reflects the namespace in the message as follows: "Error from server (NotFound): pods "my-pod-name" not found in namespace "default"".
   ([#120111](https://github.com/kubernetes/kubernetes/pull/120111), [@newtondev](https://github.com/newtondev))

* kubectl commands run inside a pod using a kubeconfig file now use the namespace specified in the kubeconfig file, instead of using the pod namespace. If no kubeconfig file is used, or the kubeconfig does not specify a namespace, the pod namespace is still used as a fallback. ([#44570](https://github.com/kubernetes/kubernetes/pull/44570), [@liggitt](https://github.com/liggitt))

* Addon manager supports HA masters. ([#55782](https://github.com/kubernetes/kubernetes/pull/55782), [@x13n](https://github.com/x13n))

* iSCSI Persistent Volume Sources can now reference CHAP Secrets in namespaces other than the namespace of the bound Persistent Volume Claim ([#51530](https://github.com/kubernetes/kubernetes/pull/51530), [@rootfs](https://github.com/rootfs))

John Howard <******@****.***> 1605827959 -0800

	return &nsMutex
}

// nsLock - provides primitives for locking critical namespace regions.
type nsLock struct {
	ref int32
	*lsync.LRWMutex
}

// nsLockMap - namespace lock map, provides primitives to Lock,
// Unlock, RLock and RUnlock.
type nsLockMap struct {
	// Indicates if namespace is part of a distributed setup.
	isDistErasure bool
	lockMap       map[string]*nsLock
	lockMapMutex  sync.Mutex

* Admission webhooks rules can now limit scope to only match namespaced, or only cluster-scoped resources with a `scope: "Cluster" | "Namespaced" | "*"` field. ([#74477](https://github.com/kubernetes/kubernetes/pull/74477), [@liggitt](https://github.com/liggitt))

- Fixes an issue that can result in namespaced custom resources being orphaned when their namespace is deleted, if the CRD defining the custom resource is removed concurrently with namespaces being deleted, then recreated. ([#93790](https://github.com/kubernetes/kubernetes/pull/93790), [@liggitt](https://github.com/liggitt)) [SIG API Machinery and Apps]

// Tests getSource().
func TestGetSource(t *testing.T) {
	currentSource := func() string { return getSource(2) }
	gotSource := currentSource()
	// Hard coded line number, 35, in the "expectedSource" value
	expectedSource := "[namespace-lock_test.go:35:TestGetSource()]"
	if gotSource != expectedSource {
		t.Errorf("expected : %s, got : %s", expectedSource, gotSource)
	}
}

// Test lock race
func TestNSLockRace(t *testing.T) {

- Kube-apiserver: fixes a 1.27+ regression watching a single namespace via the deprecated /api/v1/watch/namespaces/$name endpoint where watch events were not delivered after the watch was established ([#126151](https://github.com/kubernetes/kubernetes/pull/126151), [@xyz-li](https://github.com/xyz-li)) [SIG API Machinery and Testing]