k8s pod控制器随记

1.pod控制器类别

ReplicaSet

deployment  主要 

Horizontal Pod Autoscaler (hpa) 高可用  实现削峰填谷 

DaemonSet 守护进厂类的任务

Job 执行一次任务，执行完之后就结束

Cronjob 周期性的执行任务

StatefulSet 管理有状态应用

2.具体控制器

------------------------------------------------pod控制器------------------------------------------------------

replicaset

apiVersion: apps/v1
kind: ReplicaSet
metadata:
    name: myrs
    namespace: dev
    labels:
      controller: rs
spec:
    replicas: 3
    selector: 
       matchLabels: 
          app: nginx-pod
       matchExpressions:
       - {key: app,operator: In, Values: [nginx-pod]}
    template:
      metadata:
        labels: 
           app: nginx-pod
        spec:
           containers:
           - name: nginx
             image: nginx:1.17.1
             ports: 
             - containerPort: 80

--------------------------------------------             
apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: my-rs
  namespace: dev
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx-pod
  template:
    metadata:
      labels:
        app: nginx-pod
    spec: 
        containers:
        - name: my-nginx
          image: nginx
--------------------------------------------    

[root@node1 ~]# kubectl get rs -n dev -o wide
NAME                 DESIRED   CURRENT   READY   AGE     CONTAINERS   IMAGES   SELECTOR
my-rs                3         3         3       3m34s   my-nginx     nginx    app=nginx-pod
--------------------------------------------

[root@node1 ~]# kubectl get pod -n dev
NAME                       READY   STATUS    RESTARTS   AGE
my-rs-6wbdd                1/1     Running   0          5m
my-rs-cs6nr                1/1     Running   0          5m
my-rs-hzncc                1/1     Running   0          5m

--------------------------------------------
rs 扩缩容

kubectl edit rs my-rs -n dev  修改replicas即可

kubectl scale rs my-rs --replicas=2 -n dev
--------------------------------------------
镜像版本升级
kubectl edit rs my-rs -n dev  修改image

kubectl set image rs my-rs my-nginx=nginx:1.18.0 -n dev

删除rs

kubectl delete rs my-rs -n dev  #首先把副本数设置成0,然后再删除
kubectl delete rs my-rs -n dev --cascade=false #只删除控制器，不删除pod

kubectl delete -f my-rs.yaml 


---------------
deployment

支持replicaset的所有功能
支持版本回滚和版本回退


apiVersion: apps/v1
kind: Deployment
metadata: 
  name: mynginx
  namespace: dev
spec:
  replicas: 3
  selector: 
    matchLabels:
      run: nginx
  template:
    metadata:
      labels:
        run: nginx
    spec:
       containers:
       - image: nginx
         imagePullPolicy: IfNotPresent
         name: nginx
         ports: 
         - containerPort: 80
           protocol: TCP

kubectl apply -f yaml-nginx-deploy.yaml

kubectl delete -f yaml-nginx-deploy.yaml

查询对应的rs: 

[root@node1 ~]# kubectl get rs -n dev -o wide
NAME                 DESIRED   CURRENT   READY   AGE     CONTAINERS   IMAGES   SELECTOR
mynginx-869c47cdd9   3         3         3       3m32s   nginx        nginx    pod-template-hash=869c47cdd9,run=nginx


扩缩容：
    kubectl scale deploy my-nginx --replicas=5 -n dev
    kubectl edit deploy my-nginx -n dev

    [root@node1 ~]# kubectl scale deploy mynginx --replicas=5 -n dev
    deployment.apps/mynginx scaled
    
    kubectl edit deploy mynginx -n dev  
    修改replicas 

镜像升级:
    重建更新：
    滚动更新：(默认滚动更新) 新的起来了之后，旧的才会停止
    -----
    spec: 
        strategy: 
            type: Recreate 
    -----
    spec: 
        strategy: 
            type: RollingUpdate
            maxUnavailable: 25%
            maxSurge: 25%            
    
    kubectl set image deploy mynginx nginx=nginx -n dev    
    
    kubectl get pod -n dev -w 
    
    滚动更新 镜像升级，创建新的rs，原来的rs会进行保留，成为上一个版本
    
    

版本回退
    kubectl rollout 
    status history pause resume  restart undo 
    
    查看状态
    [root@node1 ~]# kubectl rollout status deploy mynginx -n dev
    Waiting for deployment "mynginx" rollout to finish: 1 out of 2 new replicas have been updated...
    Waiting for deployment "mynginx" rollout to finish: 1 out of 2 new replicas have been updated...
    Waiting for deployment "mynginx" rollout to finish: 1 out of 2 new replicas have been updated...
    Waiting for deployment "mynginx" rollout to finish: 1 old replicas are pending termination...
    Waiting for deployment "mynginx" rollout to finish: 1 old replicas are pending termination...
    deployment "mynginx" successfully rolled out
    
    查看历史
    kubectl rollout history deploy mynginx -n dev
    kubectl apply -f yaml-nginx-deploy.yaml --record
    
    查看历史
    [root@node1 ~]# kubectl rollout history deploy mynginx -n dev
    deployment.apps/mynginx 
    REVISION  CHANGE-CAUSE
    1         <none>
    2         <none>

    //回退版本to-revision 指定版本
    [root@node1 ~]# 
    [root@node1 ~]# 
    [root@node1 ~]# kubectl rollout undo deployment mynginx --to-revision=1 -n dev

金丝雀发布
    中间状态：灰度发布 
    
    kubectl set image deploy mynginx nginx=nginx:1.17.4 -n dev && kubectl rollout pause deploy mynginx -n dev
    
    
    
--------------------------------------------------hpa------------------------------------------
Horizontal Pod Autoscaler

手动调整改为自动调整，需要计算负载量

需要安装监控  Metrics-server

kubectl top node  查看资源使用信息

apiVersion： autoscaling/v1
kind: HorizontalPodAutoscaler
metadata:
    name: my-hpa
    namespace: dev
spec:
    minReplicas: 1
    maxReplicase: 10
    targetCPUUtilizationPercentage: 3
    scaleTargeRef:
       apiVersion: apps/v1
       kind: Deployment
       name: mynginx


--------------------------------------------------hpa------------------------------------------

网络部分cni
--------------------------------------------------DaemonSet（ds）------------------------------------------
保证集群中每个节点运行一个pod
每添加一个node,就会自动运行pod

其yaml格式同deploy


--------------------------------------------------DaemonSet------------------------------------------

--------------------------------------------------job------------------------------------------
批量处理一次性任务

job对应的pod的重启策略为Never,或者OnFailure

主要的配置项：
manualSelector: true
completions: 6 #指定运行的pod总数
parallelism：3 #并发执行总数


--------------------------------------------------Cronjob------------------------------------------
job任务创建之后立刻执行

cronjob以job为管理对象，类似cron表达式 
在指定的时间点执行任务，重复运行

schedule:                         cron表达式，最短时间为分钟
concurrencyPolicy:                并发执行任务，前一次任务没有完成，是否执行下一次任务， Allow 允许（默认）  Forbid 禁止  Replace 替换，取消当前的任务，执行新的任务
failedJobHistoryLimit:            为失败的任务保留的历史记录数目
successfulJobHistoryLimit:      为成功的任务保留历史记录数目
startingDeadlineSeconds:        启动任务错误的超时时间
jobTemplate: