如何在kubernetes中使用NodeSelector

Question

文档中给出的示例代码没有说明它可以在哪些项目上使用。你能在部署/状态集/持久卷上使用节点选择器吗？另外，当我将节点选择器放在

.spec.nodeSelector本身

spec:
  nodeSelector:
    workload: node-selector-app

当我尝试部署/statefulset/persistentvolume的演练运行时，我得到一个验证错误。那么nodeSelector只能在Pod上使用吗？

Answer 1

在persistentVolumes中不能使用nodeSelector。pod模板的规格部分应包含nodeSelector。使用nodeSelector的部署示例

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.14.2
        ports:
        - containerPort: 80
      nodeSelector:
        workload: node-selector-app

在persistentVolume中，您可以使用nodeAffinity

kubectl explain persistentVolume.spec.nodeAffinity
KIND:     PersistentVolume
VERSION:  v1

RESOURCE: nodeAffinity <Object>

DESCRIPTION:
     NodeAffinity defines constraints that limit what nodes this volume can be
     accessed from. This field influences the scheduling of pods that use this
     volume.

     VolumeNodeAffinity defines constraints that limit what nodes this volume
     can be accessed from.

FIELDS:
   required <Object>
     Required specifies hard node constraints that must be met.

举个例子：

apiVersion: v1
kind: PersistentVolume
metadata:
  name: example-local-pv
spec:
  capacity:
    storage: 500Gi
  accessModes:
  - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  storageClassName: local-storage
  local:
    path: /mnt/disks/vol1
  nodeAffinity:
    required:
      nodeSelectorTerms:
      - matchExpressions:
        - key: kubernetes.io/hostname
          operator: In
          values:
          - my-node