Kubernetes集群调度详解(节点亲和性、Pod亲和性、Taint与Toleration)

#节点硬策略。排除node02，只能在node01上运行
apiVersion: v1
kind: Pod
metadata:
  name: affinity
  labels:
    app: node-affinity-pod
spec:
  containers:
  - name: with-node-affinity
    image: hub.atguigu.com/library/myapp:v1
  affinity:            #亲和性
    nodeAffinity:        #node亲和性
      # 硬亲和性限制
      requiredDuringSchedulingIgnoredDuringExecution:
        nodeSelectorTerms:
        - matchExpressions:
          - key: kubernetes.io/hostname # 标签键名
            operator: NotIn      #键值运算关系 ，NotIn:label的值不在某个列表中。 表示不是node02节点就可运行
            values:
            - k8s-node02 # 标签键值

kubectl get node --show-labels
mkdir affi
cd affi
vim pod1.yaml
kubectl create -f pod1.yaml
kubectl get pod -o wide

#软策略
apiVersion: v1
kind: Pod
metadata:
  name: affinity2
  labels:
    app: node-affinity-pod
spec:
  containers:
  - name: with-node-affinity
    image: hub.atguigu.com/library/myapp:v1
  affinity:
    nodeAffinity:
      preferredDuringSchedulingIgnoredDuringExecution:
      - weight: 1   #权重，权重越大越亲和(多个软策略的情况)
        preference: 
          matchExpressions:
          - key: kubernetes.io/hostname
            operator: In
            values:
            - k8s-node03  # 期望是node03

 查看：kubectl get node --show-labels

#软硬合体
apiVersion: v1
kind: Pod
metadata:
  name: affinity2
  labels:
    app: node-affinity-pod
spec:
  containers:
  - name: with-node-affinity
    image: hub.atguigu.com/library/myapp:v1
  affinity:
    nodeAffinity:        #node亲和性
      # 硬亲和性限制
      requiredDuringSchedulingIgnoredDuringExecution:
        nodeSelectorTerms:
        - matchExpressions:
          - key: kubernetes.io/hostname # 标签键名
            operator: NotIn      #键值运算关系 ，NotIn:label的值不在某个列表中。 表示不是node02节点就可运行
            values:
            - k8s-node02 # 标签键值
      preferredDuringSchedulingIgnoredDuringExecution:
      - weight: 1   #权重，权重越大越亲和(多个软策略的情况)
        preference: 
          matchExpressions:
          - key: kubernetes.io/hostname
            operator: In
            values:
            - k8s-node03  # 期望是node03

apiVersion: v1
kind: Pod
metadata:
  name: pod-3
  labels:
    app: pod-3
spec:
  containers:
  - name: pod-3
    image: hub.atguigu.com/library/myapp:v1
  affinity:
    #想让两个pod运行在同一个node上
    podAffinity:
      #硬策略
      requiredDuringSchedulingIgnoredDuringExecution:
      - labelSelector:  #标签选择
          matchExpressions:
          - key: app #当app存在node-affinity-pod时就选择
            operator: In
            values: 
            - node-affinity-pod
        topologyKey: kubernetes.io/hostname 
        #hostname判断是否在同一个pod，唯一

apiVersion: v1
kind: Pod
metadata:
  name: pod-4
  labels:
    app: pod-4
spec:
  containers:
  - name: pod-4
    image: hub.atguigu.com/library/myapp:v1
  affinity:
    #不想让两个pod运行在同一个node上
    #匹配标签如果app=pod-2，那么则不运行在这个节点
    podAntiAffinity:
      #软策略
      preferredDuringSchedulingIgnoredDuringExecution:
      - weight: 1
        podAffinityTerm:
          labelSelector:
            matchExpressions:
            - key: app #匹配app=node-affinity-pod
              operator: In
              values:
              - node-affinity-pod
          topologyKey: kubernetes.io/hostname

kubectl label pod podname app=label --overwrite=true

key=value:effect

#查看节点污点
模板：kubectl describe node node-name
kubectl describe node k8s-node01

# 设置污点
模板：kubectl taint nodes node1 key1=value1:NoSchedule
kubectl taint nodes k8s-node01 check=guozige:NoExecute 
因为pod是自主式pod，没有控制器控制的pod。去除后就不存在了
如果是Deployment和StatefullSet，它就会在node02上创建，维持副本数

# 节点说明中，查找 Taints 字段
kubectl describe node k8s-node01

# 去除污点
模板：kubectl taint nodes node1 key1=value1:NoSchedule-
kubectl taint nodes k8s-node01 check=guozige:NoExecute-

tolerations:  #containers同级
- key: "check"  #能容忍的污点key
  operator: "Equal"  #Equal等于表示key=value ， Exists不等于，表示当值不等于下面value正常
  value: "guozige"  #值
  effect: "NoExecute"  #effect策略
  tolerationSeconds: 3600  #原始的pod多久驱逐，注意只有effect: "NoExecute"才能设置，不然报错

kubectl apply -f pod3.yaml
kubectl get pod -o wide

tolerations:
- operator: "Exists"

tolerations:
- key: "key"
  operator: "Exists"

kubectl taint nodes Node-Name node-role.kubernetes.io/master=:PreferNoSchedule

PreferNoSchedule
尽可能不在该节点上运行，只有当节点资源不够用才运行

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: myweb
spec:
  replicas: 7
  template:
    metadata:
      labels:
        app: myweb
    spec:
      nodeName: k8s-node01 #指定全在node01
      containers:
      - name: myweb
        image: hub.atguigu.com/library/myapp:v1
        ports:
        - containerPort: 80

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: myweb66
spec:
  replicas: 2
  template:
    metadata:
      labels:
        app: myweb66
  spec:
    nodeSelector:
      disk: ssd  #硬盘必须是ssd类型才运行
      #type: backEndNode1 #标签名，标签值
    containers:
    - name: myweb66
      image: hub.atguigu.com/library/myapp:v1
      ports:
      - containerPort: 80

kubectl label node k8s-node01 disk=ssd


kubectl label node k8s-node02 disk=ssd
kubectl edit deployment myweb66  增加副本数目
kubectl get pod 发现有些在node02上了