一、nodeAffinity

类似于nodeSelector,根据节点上的标签来调度Pod到哪些节点

二、调度策略

硬策略（required）：必须满足,不满足则Pod处于Pending状态

软策略（preferred）：尝试满足，但不保证

操作符：In、NotIn、Exists、DoseNotExist、Gt、Lt

三、示例

3.1.硬策略

affinity:
  nodeAffinity:
    requiredDuringSchedulingIgnoredDuringExecution:
      nodeSelectorTerms:
      - matchExpressions:
        - key: nodeType
          operator: In
          values:
          - dev

3.2.软策略

affinity:
  nodeAffinity:
    preferredDuringSchedulingIgnoredDuringExecution:
    - weight: 1
      preference:
        matchExpressions:
        - key: nodeType
          operator: In
          values:
          - test

如果没有nodeType=test标签的节点，则会调度到其他节点，相对于硬策略，更宽松些