k8s----节点亲和性和污点容忍

1、查看标签
kubectl  get nodes --show-labels

2、打标签
kubectl label nodes node1.com kong=true 
kubectl label nodes node2.com kong=true 
kubectl label nodes node3.com kong=true

3、node添加亲和性
spec:
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
            - matchExpressions:
              - key: kong
                operator: In
                values:
                - "true"
4、删除label
kubectl label nodes node1.com kong-

 

反亲和性

affinity:
  podAntiAffinity:
    preferredDuringSchedulingIgnoredDuringExecution:
    - weight: 100
      podAffinityTerm:
        labelSelector:
          matchExpressions:
           - key: k8s-app
             operator: In
             values:
             - my-app
        topologyKey: kubernetes.io/hostname

 

 

节点绑定 
    spec:
      containers:
      dnsPolicy: ClusterFirst
      nodeSelector:
        kubernetes.io/hostname: node03.paas

 

污点和容忍

NoSchedule：表示 pod 不会被调度到标记为 taints 的节点，只会影响新的 pod 调度
PreferNoSchedule：NoSchedule 的软策略版本，表示尽量不调度到污点节点上去，只会影响新的 pod 调度
NoExecute：该选项意味着一旦 Taint 生效，如该节点内正在运行的 pod 没有对应 Tolerate 设置，会直接被逐出

# 节点添加污点
$ kubectl taint nodes node02 xiangmu=install:NoSchedule
# 取消节点污点
 kubectl taint nodes node02 xiangmu-
# 查看节点污点
kubectl describe nodes node02|grep Taints

 
如果 operator 的值是 Exists，则 value 属性可省略
如果 operator 的值是 Equal，则表示其 key 与 value 之间的关系是 equal(等于)
如果不指定 operator 属性，则默认值为 Equal

如果pod想部署到此节点，需要添加如下内容
spec:
      containers:
      - name: nginx
        image: nginx:1.7.9
      tolerations:
      - key: "app"
        operator: "Exists"
        effect: "NoSchedule" #这里的值要和上面的的添加污点的值匹配上，不然调度不到

重要：如果只调度到此污点节点，pod还需要添加如下亲和性
kubectl  label node yq-map app=my-map

affinity:
  podAntiAffinity:
    preferredDuringSchedulingIgnoredDuringExecution:
    - weight: 100
      podAffinityTerm:
        labelSelector:
          matchExpressions:
           - key: app
             operator: In
             values:
             - my-app

 参考：https://blog.csdn.net/qq_34556414/article/details/109448632