apiVersion: v1
kind: ResourceQuota
metadata:
  name: mem-cpu-demo
spec:
  hard:
    requests.cpu: "1"
    requests.memory: 1Gi
    limits.cpu: "2"
    limits.memory: 2Gi

kind: Namespace
apiVersion: v1
metadata:
  name: test
  labels:
    name: test

replicaset：

•确保Pod数量：它会确保Kubernetes中有指定数量的Pod在运行，如果少于指定数量的Pod，RC就会创建新的，反之这会删除多余的，保证Pod的副本数量不变

•确保Pod健康：当Pod不健康，比如运行出错了，总之无法提供正常服务时，RC也会杀死不健康的Pod，重新创建新的

•弹性伸缩：在业务高峰或者低峰的时候，可以用过RC来动态的调整Pod数量来提供资源的利用率，当然我们也提到过如果使用HPA这种资源对象的话可以做到自动伸缩。

滚动升级：滚动升级是一种平滑的升级方式，通过逐步替换的策略，保证整体系统的稳定性

常用命令：

•kubectl create -f replicaset.yaml

• kubectl describe rs frontend

•kubectl edit rs frontend

•kubectl label rs frontend aa=bb

•Kubectl label rs frontend aa-

•Kubectl annotate rs frontend xx=yy

•Kubectl annotate rs frontend xx-

• kubectl get rs frontend -o yaml

•kubectl get rs -l aa=bb

•kubectl get rs -o wide

•kubectl scale rs frontend --replicas=4

•kubectl apply -f replicaset.yaml

• kubectl patch rs frontend –p ‘{“metadata”:{“labels”:{“xx”:”yy”}}}’

metadata.generation：

•metadata.generation 就是这个 ReplicationSet 的元配置数据被修改了多少次。这里就有个版本迭代的概念。每次我们使用 kuberctl edit 来修改 ReplicationSet 的配置文件，或者更新镜像，这个generation都会增长1，表示增加了一个版本。

metadata.ownerReferences：

•这个字段就是标注这个 ReplicaSet 的 Owner 信息、

•如果rs由deployment创建那么owner就为这个deployment

metadata.resourceVersion：

•这个 resourceVersion 就是这个资源对象当前的版本号。

apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: frontend
  labels:
    app: guestbook
    tier: frontend
spec:
  # this replicas value is default
  # modify it according to your case
  replicas: 3
  selector:
    matchLabels:
      tier: frontend
    matchExpressions:
      - {key: tier, operator: In, values: [frontend]}
  template:
    metadata:
      labels:
        app: guestbook
        tier: frontend
    spec:
      containers:
      - name: php-redis
        image: iaasfree/gb-frontend:v3 
        resources:
          requests:
            cpu: 10m
            memory: 10Mi
        env:
        - name: GET_HOSTS_FROM
          value: dns
          # If your cluster config does not include a dns service, then to
          # instead access environment variables to find service host
          # info, comment out the 'value: dns' line above, and uncomment the
          # line below.
          # value: env
        ports:
        - containerPort: 80

hpa：

apiVersion: autoscaling/v1
kind: HorizontalPodAutoscaler
metadata:
  name: frontend-hpa
  labels:
    software: apache
    project: frontend
    app: hpa
    version: v1
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: ReplicaSet
    name: frontend
  minReplicas: 1
  maxReplicas: 5
  targetCPUUtilizationPercentage: 10

deployment：

•Deployment为Pod和Replica Set提供声明式更新。

你只需要在 Deployment 中描述您想要的目标状态是什么，Deployment controller 就会帮您将 Pod 和ReplicaSet 的实际状态改变到您的目标状态。您可以定义一个全新的 Deployment 来创建 ReplicaSet 或者删除已有的 Deployment 并创建一个新的来替换。
注意：您不该手动管理由 Deployment 创建的 Replica Set，否则您就篡越了 Deployment controller 的职责！

常用命令：

•kubectl set image deployment nginx-deployment nginx=nginx:1.13

•kubectl delete -f nginx-deploy.yaml

•kubectl create -f nginx-deploy.yaml

•kubectl apply -f nginx-deploy.yaml

•kubectl edit deploy nginx-deployment

•kubectl label deploy nginx-deployment stage=test

•kubectl label deploy nginx-deployment stage-

•kubectl annotate deploy nginx-deployment anno=xx

•kubectl annotate deploy nginx-deployment anno-

•kubectl replace -f nginx-deploy.yaml

•Kubectl patch deploy nginx-deployment –p ‘{“matadata”:{“labels”:{“aa”:”bb”}}}’

•kubectl diff -f nginx-deploy.yaml

•Kubectl describe deploy nginx-deployment

•kubectl rollout history deploy/nginx-deployment

•kubectl rollout pause deploy/nginx-deployment

•kubectl rollout resume deploy/nginx-deployment

•kubectl rollout restart deploy/nginx-deployment

•kubectl rollout status deploy/nginx-deployment

•kubectl rollout undo deploy/nginx-deployment

•kubectl rollout undo daemonset/abc --to-revision=3

•kubectl scale deploy nginx-deployment --replicas=3

•kubectl autoscale deployment foo --min=2 --max=10

•kubectl autoscale deployment foo --max=5 --cpu-percent=80

•kubectl set image deploy nginx-deployment nginx=nginx:1.17.6

•kubectl set image deploy nginx-deployment nginx=nginx:1.17.6 --record=true

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  selector:
    matchLabels:
      app: nginx
  replicas: 2
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx
        ports:
        - containerPort: 80

hpa：

apiVersion: autoscaling/v1
kind: HorizontalPodAutoscaler
metadata:
  name: nginx-hpa
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: nginx-deployment
  minReplicas: 1
  maxReplicas: 5
  targetCPUUtilizationPercentage: 10

rollingupdate：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
  selector:
    matchLabels:
      app: nginx
  replicas: 2
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx
        ports:
        - containerPort: 80

recreate：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  strategy:
    type: Recreate
  selector:
    matchLabels:
      app: nginx
  replicas: 2
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx
        ports:
        - containerPort: 80

progressDeadlineSeconds:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  progressDeadlineSeconds: 1
  selector:
    matchLabels:
      app: nginx
  replicas: 2
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx
        ports:
        - containerPort: 80

revisionHistoryLimit:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  revisionHistoryLimit: 2
  selector:
    matchLabels:
      app: nginx
  replicas: 2
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx
        ports:
        - containerPort: 80