注意点

同时指定 nodeSelector 和 nodeAffinity ，必须两个条件都满足
指定多个 nodeSelectorTerms 有一个匹配即可
一个 nodeSelectorTerms 中有多个 matchExpressions, 必须全部满足
node 标签变化，已经调度完成的 pod 不受影响
软亲和没有符合节点 pod 调度其他，硬亲和没有符合节点 pod 处于 Pending

pod.spec.affinity.nodeAffinity

软策略

pod.spec.affinity.nodeAffinity.preferredDuringSchedulingIgnoredDuringExecution

apiVersion: apps/v1
kind: Deployment
metadata:
  name: web-dep
spec:
  replicas: 5
  selector:
    matchLabels:
      app: web-dep
  template:
    metadata:
      labels:
        app: web-dep
    spec:
      containers:
      - image: nginx
        name: web-dep-nginx
      affinity:
        nodeAffinity:
          preferredDuringSchedulingIgnoredDuringExecution:
          - weight: 10
            preference:
              matchExpressions:
              - key: kubernetes.io/hostname
                operator: In
                values:
                - node03
                - node04
          - weight: 90
            preference:
              matchExpressions:
              - key: kubernetes.io/hostname
                operator: In
                values:
                - node01
                - node02

硬策略

pod.spec.affinity.nodeAffinity.requiredDuringSchedulingIgnoredDuringExecution

apiVersion: apps/v1
kind: Deployment
metadata:
  name: web-dep
spec:
  replicas: 5
  selector:
    matchLabels:
      app: web-dep
  template:
    metadata:
      labels:
        app: web-dep
    spec:
      containers:
      - image: nginx
        name: web-dep-nginx
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
            - matchExpressions:
              - key: kubernetes.io/hostname
                operator: In
                values:
                - node01
                - node02
                - node03
                - node04

参数整理

键值运算关系

operator
In key 的 值 在 value 列表
NotIn key 的 值 不在 value 列表
Gt key 的 值 大于
Lt key 的 值 小于
Exists 只判断 key 存在，不写 value
DoesNotExist 只判断 key 不存在，不写 value