K8S对node添加label，并根据label筛选节点

某些特殊情况下，需要将某些服务固定在一台宿主机上，K8S也适应这种方式，下面以mongo为例，来看看如何实现的：

kubectl label nodes kube-node node=kube-nodekubectl get node -a -l "node=kube-node"

pod或者rc的配置项中添加如下配置：

nodeSelector:        node: kube-node4

如mongo启动的rc文件

apiVersion: v1kind: ReplicationControllermetadata: name: mongospec: replicas: 1  template:   metadata:     labels:       run: mongo   spec:     containers:     - name: mongo       image: daocloud.io/library/mongo:3.2.4       ports:         - containerPort: 27017       volumeMounts:         - mountPath: /data/db           name: mongo     volumes: [{"name":"mongo","hostPath":{"path":"/root/volumes/mongo"}}]     nodeSelector:        node: kube-node4