node pod亲和性affinity

位置：deploy.spec.template.spec.affinity

硬亲和和软亲和说明：（不管是node还是pod都可以用软亲和或者硬亲和）

1. requiredDuringSchedulingIgnoredDuringExecution（硬亲和）：必须满足，如果不满足则不进行调度
2. preferredDuringSchedulingIgnoredDuringExecution（软亲和）：倾向满足，不满足的情况下会调度的不符合条件的Node上。

Node亲和性：

nodeAffinity

apiVersion: v1
kind: Pod
metadata:
  name: nginx
spec:
  affinity:
    nodeAffinity:
      requiredDuringSchedulingIgnoredDuringExecution: #硬亲和
        nodeSelectorTerms: 
        - matchExpressions:
          - key: kubernetes.io/e2e-az-name #NODE的key
            operator: In   #在
            values:   #值里面
            - e2e-az1 
            - e2e-az2
      preferredDuringSchedulingIgnoredDuringExecution:#软亲和
      - weight: 1               //取值范围1-100
        preference:
          matchExpressions:
          - key: another-node-label-key
            operator: In
            values:
            - another-node-label-value
  containers:
  - name: nginx
    image: docker.io/nginx

Pod亲和性：

podAffinity：pod和pod运行在一起

apiVersion: v1
kind: Pod
metadata:
  name: with-pod-affinity
spec:
  affinity:
    podAffinity:
      requiredDuringSchedulingIgnoredDuringExecution: #硬亲和，必须满足
      - labelSelector: #pod标签选择器
          matchExpressions:
          - key: security  #key
            operator: In   #在
            values:
            - S1           #value的列表
        topologyKey: kubernetes.io/hostname  #通过node的hostname判断是否是相同节点，节点名一定不能一样
  containers:
  - name: with-pod-affinity
    image: k8s.gcr.io/pause:2.0

podAntiAffinity： pod和pod不能在一起

apiVersion: v1
kind: Pod
metadata:
  name: with-pod-affinity
spec:
  affinity:
    podAntiAffinity:
      preferredDuringSchedulingIgnoredDuringExecution: #软亲和
      - weight: 100 #权重
        podAffinityTerm:
          labelSelector:
            matchExpressions:
            - key: security
              operator: In
              values:
              - S2   #pod label security=s2,则不能调度
          topologyKey: kubernetes.io/hostname #通过node的hostname判断是否是相同节点，节点名一定不能一样
  containers:
  - name: with-pod-affinity
    image: k8s.gcr.io/pause:2.0