6、kubernetes资源清单之Pod控制器190714

一、Pod控制器的类别

ReplicationController：早期唯一的控制器，已废弃
ReplicaSet：控制Pod满足用户期望副本；标签选择器选择由自己管理的Pod副本；Pod资源模板完成Pod资源的新建。主要用于管理无状态的Pod，不建议直接使用此控制器
Deployment：基于ReplicaSet控制器；建议使用此控制器，支持滚动更新和回滚，管理无状态应用
DaemonSet：守护进程类的控制器，例如每台node都启动一个Pod一直持续下去
Job：执行一次性的任务，完成后就退出，如果没有完成则重新构建一个Pod运行
Cronjob：周期性运行的任务
StatefulSet：管理有状态的应用，每个Pod都是单独管理

二、ReplicaSet控制器

kubectl explain rs：获取帮助手册

# cat rs-damo.yaml

apiVersion: apps/v1

kind: ReplicaSet

metadata:  #ReplicaSet的metadata

  name: myapp-rs

  namespace: default

spec:  #ReplicaSet的spec

  replicas: 2

  selector:

    matchLabels:  #标签选择器，用于控制器选择控制符合条件的pod

      app: myapp

      release: canary

  template:

    metadata:

      name: myapp-pod  #此处pod名会被控制器的名字代替

      labels:  #此处为Pod的标签，必须符合控制器的标签选择器定义的条件

        app: myapp

        release: canary

    spec:

      containers:

      - name: myapp-container

        image: dongfeimg/myapp:v1

        ports:

        - name: http

          containerPort: 80

# kubectl get rs

# kubectl get pods

扩容/缩容

# kubectl edit rs myapp-rs

spec:

  replicas: 10  #将此值改

升级/回滚

# kubectl edit rs myapp-rs

    spec:

      containers:

      - image: dongfeimg/myapp:v2  #修改此值不能立即更新，原有pod删除后重建会升级到v2版本

三、Deployment控制器

kubectl explain deploy

# cat deploy-damo.yaml

apiVersion: apps/v1

kind: Deployment

metadata:

  name: myapp-deploy

  namespace: default

spec:

  replicas: 2

  selector:

    matchLabels:

      app: myapp

      release: canary

  template:

    metadata:

      labels:

        app: myapp

        release: canary

    spec:

      containers:

      - name: myapp-container

        image: dongfeimg/myapp:v1

        ports:

        - name: http

          containerPort: 80

# kubectl apply -f deploy-damo.yaml  #声明式创建

# kubectl get deploy  #deploy控制rs

# kubectl get rs  #rs控制pod

# kubectl get pods

使用修改清单文件的方式扩容、缩容、更新和回滚等操作

# vim deploy-damo.yaml

spec:

  replicas: 3  #将副本扩容至3个

# kubectl apply -f deploy-damo.yaml

# vim deploy-damo.yaml

    spec:

      containers:

      - name: myapp-container

        image: dongfeimg/myapp:v2  #将版本更新为v2

# kubectl apply -f deploy-damo.yaml

# kubectl rollout history deployment myapp-deploy  #查看升级的历史信息

使用kubectl patch的方式扩容、缩容、更新和回滚等操作

# kubectl patch deployment myapp-deploy -p '{"spec":{"replicas":5}}'  #传入json格式的数组来实现扩容

# kubectl patch deployment myapp-deploy -p '{"spec":{"strategy":{"rollingUpdate":{"maxSurge":1,"maxUnavailable":0}}}}'  #"maxSurge":1 最大在更新pod数，"maxUnavailable":0 允许最大不可用的pod

# kubectl describe deployment myapp-deploy |grep RollingUpdateStrategy  #验证

kubectl set image和kubectl rollout pause

# kubectl set image deployment myapp-deploy myapp-container=dongfeimg/myapp:v3 \  #将容器版本更新至v3

  && kubectl rollout pause deployment myapp-deploy  #在更新第一个的时候暂停，金丝雀发布

# kubectl rollout resume deployment myapp-deploy  #继续此前的更新

kubectl rollout undo：回滚

# kubectl rollout history deployment myapp-deploy

# kubectl rollout undo deployment myapp-deploy --to-revision=1  #回滚至v1

四、DaemonSet控制器

在集群中符合选择器的node上一个pod，例如在每个节点上运行一个filebeat来收集日志
kubectl explain ds

# cat ds-damo.yaml

apiVersion: apps/v1

kind: Deployment

metadata:

  name: redis

  namespace: default

spec:

  replicas: 1

  selector:

    matchLabels:

      app: redis

      role: logstor

  template:

    metadata:

      labels:

        app: redis

        role: logstor

    spec:

      containers:

      - name: redis

        image: redis:4.0

        ports:

        - name: redis

          containerPort: 6379

---

apiVersion: apps/v1

kind: DaemonSet

metadata:

  name: filebeat-ds

  namespace: default

spec:

  selector:

    matchLabels:

      app: filebeat

      release: stable

  template:

    metadata:

      labels:

        app: filebeat

        release: stable

    spec:

      containers:

      - name: filebeat-container

        image: dongfeimg/filebeat:5.6.5-alpine

        env:

        - name: REDIS_HOST

          value: redis.default.svc.cluster.local  #redis-server的主机名(svc)

        - name: REDIS_LOG_LEVEL

          value: info

# kubectl expose deployment redis --port=6379

巴特西

6、kubernetes资源清单之Pod控制器190714

一、Pod控制器的类别

二、ReplicaSet控制器

三、Deployment控制器

四、DaemonSet控制器

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