用来区分多个虚拟集群

kubectl get namespace|ns

default 没有指明使用其它命名空间的对象所使用的默认命名空间、
kube-system  系统创建对象所使用的命名空间。
kube-public 公共资源使用。基本没啥用。

kubectl get pods -n kube-system

kubectl api-resources --verbs=list --namespaced -o name | xargs -n 1 kubectl get --show-kind --ignore-not-found -n kube-node-lease

kube-node-lease is a Kubernetes control plane component that is responsible for managing and renewing the lease of nodes in the cluster. It is part of the Kubernetes “lease” API group and is used to ensure that a node is operational and available to the cluster.

The kube-node-lease component creates a lease object for each node in the cluster. The lease object contains information such as the node name, the ID of the controller managing the lease, and the time that the lease will expire. The controller that manages the lease is typically the kube-controller-manager.

The lease is automatically renewed by the kube-node-lease component as long as the node is operational and available to the cluster. If the node becomes unavailable, the lease will expire and the node will be marked as “NotReady” in the Kubernetes API server. This allows other components, such as the Kubernetes scheduler, to avoid scheduling pods on the unavailable node.

Overall, kube-node-lease plays an important role in ensuring the availability and reliability of the Kubernetes cluster by managing the lease of nodes.