K8S：几种资源调度方式-RC/RS/Deployment/StatefulSet/DaemonSet

apiVersion: v1
kind: ReplicationController
metadata:
  name: nginx
spec:
  replicas: 3 #副本数
  selector:
    app: nginx
  template:
    metadata:
      name: nginx
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx
        ports:
        - containerPort: 80　　

apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: frontend
  labels:
    app: test
    version: v2
spec:
  replicas: 3
  selector:
    matchLabels:
      version: v2
    matchExpressions: #集合式标签选择器,允许同时有v1和v2两个版本的pod。
      - {key: version, operator: In, values: [v1,v2]}
  template:
    metadata:
      labels:
        app: test
        version: v2
    spec:
      containers:
      - name: nginx
        image: nginx:1.15.2
        resources:
          requests:
            cpu: 100m
            memory: 100Mi
        env:
        - name: IS_env
          value: env
        ports:
        - containerPort: 80　　

apiVersion: apps/v1
kind: Deployment
metadata:
  annotations:
    deployment.kubernetes.io/revision: "1"
  creationTimestamp: "2021-06-16T07:49:17Z"
  generation: 1
  labels:  #deploy自身的标签
    app: nginx
  name: nginx
  namespace: test-wang
spec:
  progressDeadlineSeconds: 600
  replicas: 1 #副本数
  revisionHistoryLimit: 10 #保留历史记录的次数，设置为0的话，不保留历史数据
  # minReadySeconds: 0 #可选参数，指定新创建的Pod在没有任何容器崩溃的情况下视为Ready最小的秒数，
默认为0，即一旦被创建就视为可用。
  selector: #匹配RS，一旦创建就不建议修改，否则RS会脱离deploy的掌控
    matchLabels: 
      app: nginx
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate 
#更新deployment的方式 1.RollingUpdate：滚动更新(默认)，可以指定
maxSurge(超过期望值的最大Pod数，默认25%)和maxUnavailable(最大不可用数量，默认25%)
2.Recreate 重建 先删除旧的Pod，在创建新的Pod
  template:
    metadata: #匹配Pod，要和匹配RS的一致
      creationTimestamp: null
      labels:
        app: nginx
    spec: #和Pod的一致。
      containers:
      - image: nginx:1.15.2
        imagePullPolicy: IfNotPresent
        name: nginx
        resources: {}
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 30

kubectl get deploy -n test-wang -o wide
NAME    READY   UP-TO-DATE   AVAILABLE   AGE     CONTAINERS   IMAGES         SELECTOR
nginx   1/1     1            1           5m23s   nginx        nginx:1.15.2   app=nginx

kubectl create -f XXX.yaml

kubectl set image deploy nginx nginx=nginx:1.15.3

kubectl rollout history deploy nginx #查看历史版本
kubectl rollout undo deploy nginx #回滚到上一个版本
kubectl  rollout history deploy nginx #查看历史记录
kubectl rollout history deploy nginx --revision=3 #查看某个版本的详细信息
kubectl rollout undo deploy nginx --to-revision=3 #回滚到某个版本
kubectl rollout pause deployment nginx #暂停
kubectl rollout resume deploy nginx #恢复

statefulSetName-{0..N-1}.serviceName.namespace.svc.cluster.local

port 6379
slaveof redis-ms-0.redis-ms.public-service.svc.cluster.local 6379
tcp-backlog 511
timeout 0
tcp-keepalive 0

apiVersion: v1
kind: Service
metadata:
  name: nginx #Service定义了一个名字为Nginx的Headless Service，k8s所创建的Service格式为nginx-0.nginx.default.svc.cluster.local，其他的类似
  namespace: test-k8s
  labels:
    app: nginx
spec:
  ports:
  - port: 80
    name: web
  clusterIP: None #设置None后不会有clusterIP，但是可以通过无头服务访问到它，不强制要求设置None，可以避免资源的浪费
  selector:
    app: nginx
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web # StatefulSet定义了一个名字为web的StatefulSet，replicas表示部署Pod的副本数，本实例为2，当StatefulSet控制器创建Pod时，它会添加一个标签statefulset.kubernetes.io/pod-name，该标签的值为Pod的名称，用于匹配Service。
  namespace: test-k8s
spec:
  serviceName: "nginx"
  replicas: 2
  selector: #在StatefulSet中必须设置Pod选择器用来匹配其标签（.spec.template.metadata.labels）。在1.8版本之前，如果未配置该字段，将被设置为默认值，在1.8版本之后，如果未指定匹配Pod Selector，则会导致StatefulSet创建错误
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx
        ports:
        - containerPort: 80
          name: web

kubectl delete sts web --cascade=false

apiVersion: apps/v1
kind: DaemonSet
metadata:
  labels:
    app: nginx
  name: nginx
  namespace: test-k8s
spec:
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: nginx
  updateStrategy: #滚动更新策略
    rollingUpdate:
       maxUnavailabel: 1 #滚动更新时最大不可用数目
    type: RollingUpdate 
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx:1.15.2
        imagePullPolicy: IfNotPresent
        name: nginx
        resources: {}
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 30