节点亲和性

pod.spec.nodeAffinity

• preferredDuringSchedulingIgnoredDuringExecution：软策略

• requiredDuringSchedulingIgnoredDuringExecution：硬策略

requiredDuringSchedulingIgnoredDuringExecution

apiVersion: v1
kind: Pod
metadata:
  name: affinity
  labels:
    app: node-affinity-pod
spec:
  containers:
  - name: with-node-affinity
    image: wangyanglinux/myapp:v1
  affinity:
    nodeAffinity:
      requiredDuringSchedulingIgnoredDuringExecution:
        nodeSelectorTerms:
        - matchExpressions:
          - key: kubernetes.io/hostname
            operator: NotIn
            values:
            - k8s-node02

apiVersion: v1
kind: Pod
metadata:
  name: affinity
  labels:
    app: node-affinity-pod
spec:
  containers:
  - name: with-node-affinity
    image: wangyanglinux/myapp:v1
  affinity:
    nodeAffinity:
      requiredDuringSchedulingIgnoredDuringExecution:
        nodeSelectorTerms:
        - matchExpressions:
          - key: kubernetes.io/hostname
            operator: In
            values:
            - k8s-node02

preferredDuringSchedulingIgnoredDuringExecution

apiVersion: v1
kind: Pod
metadata:
  name: affinity
  labels:
    app: node-affinity-pod
spec:
  containers:
  - name: with-node-affinity
    image: wangyanglinux/myapp:v1
  affinity:
    nodeAffinity:
      preferredDuringSchedulingIgnoredDuringExecution:
      - weight: 1
        preference:
          matchExpressions:
          - key: kubernetes.io/hostname
            operator: In
            values:
            - k8s-node02

合体

apiVersion: v1
kind: Pod
metadata:
  name: affinity
  labels:
    app: node-affinity-pod
spec:
  containers:
  - name: with-node-affinity
    image: wangyanglinux/myapp:v1
  affinity:
    nodeAffinity:
      requiredDuringSchedulingIgnoredDuringExecution:
        nodeSelectorTerms:
        - matchExpressions:
          - key: kubernetes.io/hostname
            operator: NotIn
            values:
            - k8s-node02
      preferredDuringSchedulingIgnoredDuringExecution:
      - weight: 1
        preference:
          matchExpressions:
          - key: kubernetes.io/hostname
            operator: In
            values:
            - k8s-node01

键值运算关系

• In：label 的值在某个列表中

• NotIn：label 的值不在某个列表中

• Gt：label 的值大于某个值

• Lt：label 的值小于某个值

• Exists：某个 label 存在

• DoesNotExist：某个 label 不存在

Pod 亲和性

pod.spec.affinity.podAffinity/podAntiAffinity

• preferredDuringSchedulingIgnoredDuringExecution：软策略

• requiredDuringSchedulingIgnoredDuringExecution：硬策略

apiVersion: v1
kind: Pod
metadata:
  name: node01
  labels:
    app: node01
spec:
  containers:
  - name: node01
    image: wangyanglinux/myapp:v1

apiVersion: v1
kind: Pod
metadata:
  name: pod-3
  labels:
    app: pod-3
spec:
  containers:
  - name: pod-3
    image: wangyanglinux/myapp:v1
  affinity:
    podAffinity:
      requiredDuringSchedulingIgnoredDuringExecution:
      - labelSelector:
          matchExpressions:
          - key: app
            operator: In
            values:
            - node01
        topologyKey: kubernetes.io/hostname

将app=node01改成app=node02时，就不能匹配了

apiVersion: v1
kind: Pod
metadata:
  name: pod-3
  labels:
    app: pod-3
spec:
  containers:
  - name: pod-3
    image: wangyanglinux/myapp:v1
  affinity:
    podAntiAffinity:
      preferredDuringSchedulingIgnoredDuringExecution:
      - weight: 1
        podAffinityTerm:
          labelSelector:
            matchExpressions:
            - key: app
              operator: In
              values:
              - node01
          topologyKey: kubernetes.io/hostname

亲和性/反亲和性调度策略比较如下：