7、用 label 控制 Pod 的位置

Assigning Pods to Nodes | KubernetesYou can constrain a Pod so that it is restricted to run on particular node(s), or to prefer to run on particular nodes. There are several ways to do this and the recommended approaches all use label selectors to facilitate the selection. Often, you do not need to set any such constraints; the scheduler will automatically do a reasonable placement (for example, spreading your Pods across nodes so as not place Pods on a node with insufficient free resources).https://kubernetes.io/docs/concepts/scheduling-eviction/assign-pod-node/

默认配置下，Scheduler会将Pod调度到所有可用的Node节点。

但有时我们 希望 Pod部署到指定的Node。

Kubernetes 是通过 label 来实现这个功能的。

label 是 key-value 对，各种资源都可以设置 label，灵活添加各种自定义属性。

一个资源对象可以定义任意数量的lab