Pod控制器概述 引入 Pod是kubernetes的最小管理单元,在kubernetes中,按照pod的创建方式可以将其分为两类:
自主式pod:kubernetes直接创建出来的Pod,这种pod删除后就没有了,也不会重建
控制器创建的pod:kubernetes通过控制器创建的pod,这种pod删除了之后还会自动重建
控制器 Pod控制器是管理pod的中间层,使用Pod控制器之后,只需要告诉Pod控制器,想要多少个什么样的Pod就可以了,它会创建出满足条件的Pod并确保每一个Pod资源处于用户期望的目标状态。如果Pod资源在运行中出现故障,它会基于指定策略重新编排Pod。
类别 在kubernetes中,有很多类型的pod控制器,每种都有自己的适合的场景,常见的有下面这些:
ReplicationController:比较原始的pod控制器,已经被废弃,由ReplicaSet替代
ReplicaSet:保证副本数量一直维持在期望值,并支持pod数量扩缩容,镜像版本升级
Deployment:通过控制ReplicaSet来控制Pod,并支持滚动升级、回退版本
Horizontal Pod Autoscaler:可以根据集群负载自动水平调整Pod的数量,实现削峰填谷
DaemonSet:在集群中的指定Node上运行且仅运行一个副本,一般用于守护进程类的任务
Job:它创建出来的pod只要完成任务就立即退出,不需要重启或重建,用于执行一次性任务
Cronjob:它创建的Pod负责周期性任务控制,不需要持续后台运行
StatefulSet:管理有状态应用
ReplicaSet(RS) 概述 ReplicaSet的主要作用是保证一定数量的pod正常运行 ,它会持续监听这些Pod的运行状态,一旦Pod发生故障,就会重启或重建。同时它还支持对pod数量的扩缩容和镜像版本的升降级。
资源清单 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 apiVersion: apps/v1 kind: ReplicaSet metadata: name: namespace: labels: spec: replicas: <副本数量> selector: matchLabels: matchExpressions: - {key: <lableskey> , operator: <匹配方式> , values: <lablesvalue> } template: metadata: labels: spec: containers: - name: image: ports:
**replicas:**指定副本数量,其实就是当前rs创建出来的pod的数量,默认为1
**selector:**选择器,它的作用是建立pod控制器和pod之间的关联关系,采用的Label Selector机制。在pod模板上定义label,在控制器上定义选择器,就可以表明当前控制器能管理哪些pod了
**template:**模板,就是当前控制器创建pod所使用的模板板,里面其实就是前一章学过的pod的定义
创建RS 创建Pc-Replicaset.yaml文件,内容如下:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 apiVersion: apps/v1 kind: ReplicaSet metadata: name: pc-replicaset namespace: default spec: replicas: 3 selector: matchLabels: app: nginx-pod template: metadata: labels: app: nginx-pod spec: containers: - name: nginx image: docker.io/library/nginx:1.23.1
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 [root@master yaml]# kubectl create -f Pc-Replicaset.yaml replicaset.apps/pc-replicaset created [root@master yaml]# kubectl get rs pc-replicaset -n default -o wide NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR pc-replicaset 3 3 3 2m41s nginx docker.io/library/nginx:1.23.1 app=nginx-pod [root@master yaml]# kubectl get pod -n default NAME READY STATUS RESTARTS AGE pc-replicaset-fvjg2 1/1 Running 0 3m53s pc-replicaset-lzfc2 1/1 Running 0 3m53s pc-replicaset-q7hrm 1/1 Running 0 3m53s
扩缩容 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 [root@master yaml]# kubectl edit rs pc-replicaset -n default replicaset.apps/pc-replicaset edited [root@master yaml]# kubectl get pod -n default NAME READY STATUS RESTARTS AGE pc-replicaset-49zl6 1/1 Running 0 67s pc-replicaset-5ngpl 1/1 Running 0 67s pc-replicaset-fvjg2 1/1 Running 0 6m45s pc-replicaset-lzfc2 1/1 Running 0 6m45s pc-replicaset-pnstd 1/1 Running 0 67s pc-replicaset-q7hrm 1/1 Running 0 6m45s [root@master yaml]# kubectl scale rs pc-replicaset --replicas=2 -n default replicaset.apps/pc-replicaset scaled [root@master yaml]# kubectl get pod -n default|grep pc NAME READY STATUS RESTARTS AGE pc-replicaset-fvjg2 1/1 Running 0 8m39s pc-replicaset-q7hrm 1/1 Running 0 8m39s
镜像升级 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 [root@master yaml]# kubectl edit rs pc-replicaset -n default replicaset.apps/pc-replicaset edited [root@master yaml]# kubectl get rs -n default -o wide NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR pc-replicaset 2 2 2 14m nginx docker.io/library/nginx:latest app=nginx-pod [root@master yaml]# kubectl set image rs pc-replicaset nginx=docker.io/library/nginx:1.23.1 -n default replicaset.apps/pc-replicaset image updated [root@master yaml]# kubectl get rs -n default -o wide NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR pc-replicaset 2 2 2 17m nginx docker.io/library/nginx:1.23.1 app=nginx-pod
删除RS 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 [root@master yaml]# kubectl delete rs pc-replicaset -n default replicaset.apps "pc-replicaset" deleted [root@master yaml]# kubectl get pod -n default -o wide No resources found in default namespace. [root@master yaml]# kubectl delete rs pc-replicaset -n default --cascade=false replicaset.apps "pc-replicaset" deleted [root@master yaml]# kubectl get pods -n default NAME READY STATUS RESTARTS AGE pc-replicaset-cl82j 1/1 Running 0 75s pc-replicaset-dslhb 1/1 Running 0 75s [root@master yaml]# kubectl delete -f Pc-Replicaset.yaml replicaset.apps "pc-replicaset" deleted
Deployment(Deploy) 概述 kubernetes在V1.2版本开始,引入了Deployment控制器。值得一提的是,这种控制器并不直接管理pod,而是通过管理ReplicaSet来简介管理Pod,即:Deployment管理ReplicaSet,ReplicaSet管理Pod。所以Deployment比ReplicaSet功能更加强大。
Deployment主要功能有下面几个:
支持ReplicaSet的所有功能
支持发布的停止、继续
支持滚动升级和回滚版本
资源清单 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 apiVersion: apps/v1 kind: Deployment metadata: name: namespace: labels: spec: replicas: <副本数量> revisionHistoryLimit: <保留历史版本数量> paused: false progressDeadlineSeconds: 600 strategy: type: <更新策略> rollingUpdate: maxSurge: 30 % maxUnavailable: 30 % selector: matchLabels: matchExpressions: - {key: <lableskey> , operator: <匹配方式> , values: <lablesvalue> } template: metadata: labels: spec: containers: - name: image: ports:
创建deploy 创建Pc-Deployment.yaml,内容如下
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 apiVersion: apps/v1 kind: Deployment metadata: name: pc-deployment namespace: default spec: replicas: 3 selector: matchLabels: app: nginx-pod template: metadata: labels: app: nginx-pod spec: containers: - name: nginx image: docker.io/library/nginx:1.23.1
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 [root@master yaml]# kubectl create -f Pc-Deployment.yaml --record=true Flag --record has been deprecated, --record will be removed in the future deployment.apps/pc-deployment created [root@master yaml]# kubectl get deploy pc-deployment -n default NAME READY UP-TO-DATE AVAILABLE AGE pc-deployment 3/3 3 3 85s [root@master yaml]# kubectl get rs -n default NAME DESIRED CURRENT READY AGE pc-deployment-6895856946 3 3 3 2m14s [root@master yaml]# kubectl get pods -n default NAME READY STATUS RESTARTS AGE pc-deployment-6895856946-7nbs4 1/1 Running 0 3m30s pc-deployment-6895856946-g5n6g 1/1 Running 0 3m30s pc-deployment-6895856946-jkqnm 1/1 Running 0 3m30s
扩缩容 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 [root@master yaml]# kubectl scale deploy pc-deployment --replicas=5 -n default deployment.apps/pc-deployment scaled [root@master yaml]# kubectl get deploy pc-deployment -n default NAME READY UP-TO-DATE AVAILABLE AGE pc-deployment 5/5 5 5 3m24s [root@master yaml]# kubectl get pods -n default NAME READY STATUS RESTARTS AGE pc-deployment-6895856946-2tpfc 1/1 Running 0 4m2s pc-deployment-6895856946-5pn96 1/1 Running 0 4m2s pc-deployment-6895856946-792dj 1/1 Running 0 4m2s pc-deployment-6895856946-89vrz 1/1 Running 0 117s pc-deployment-6895856946-hl7pz 1/1 Running 0 117s [root@master yaml]# kubectl edit deploy pc-deployment -n default deployment.apps/pc-deployment edited [root@master yaml]# kubectl get deploy pc-deployment -n default NAME READY UP-TO-DATE AVAILABLE AGE pc-deployment 3/3 3 3 6m18s [root@master yaml]# kubectl get pods -n default NAME READY STATUS RESTARTS AGE pc-deployment-6895856946-792dj 1/1 Running 0 6m44s pc-deployment-6895856946-89vrz 1/1 Running 0 6m44s pc-deployment-6895856946-792dj 1/1 Running 0 6m44s
镜像更新 deployment支持两种更新策略:重建更新
和滚动更新
,可以通过strategy
指定策略类型,支持两个属性:
1 2 3 4 5 6 7 strategy:指定新的Pod替换旧的Pod的策略, 支持两个属性: type:指定策略类型,支持两种策略 Recreate:在创建出新的Pod之前会先杀掉所有已存在的Pod RollingUpdate:滚动更新,就是杀死一部分,就启动一部分,在更新过程中,存在两个版本Pod rollingUpdate:当type为RollingUpdate时生效,用于为RollingUpdate设置参数,支持两个属性: maxUnavailable:用来指定在升级过程中不可用Pod的最大数量,默认为25%。 maxSurge: 用来指定在升级过程中可以超过期望的Pod的最大数量,默认为25%。
重建更新 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 [root@master yaml]# vim Pc-Deployment.yaml [root@master yaml]# kubectl apply -f Pc-Deployment.yaml deployment.apps/pc-deployment configured [root@master yaml]# kubectl set image deployment pc-deployment nginx=docker.io/library/nginx:latest -n default deployment.apps/pc-deployment image updated [root@master yaml]# kubectl get pods -n default -w NAME READY STATUS RESTARTS AGE pc-deployment-6895856946-9zvpn 1/1 Terminating 0 5s pc-deployment-6895856946-bnz2v 1/1 Terminating 0 5s pc-deployment-6895856946-6dswz 0/1 Terminating 0 5s pc-deployment-74556686fb-f76kc 0/1 Pending 0 0s pc-deployment-74556686fb-g48rh 0/1 Pending 0 0s pc-deployment-74556686fb-m2rvf 0/1 Pending 0 0s pc-deployment-74556686fb-f76kc 0/1 ContainerCreating 0 0s pc-deployment-74556686fb-g48rh 0/1 ContainerCreating 0 0s pc-deployment-74556686fb-m2rvf 0/1 ContainerCreating 0 0s pc-deployment-74556686fb-g48rh 1/1 Running 0 1s pc-deployment-74556686fb-f76kc 1/1 Running 0 2s pc-deployment-74556686fb-m2rvf 1/1 Running 0 2s
滚动更新 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 [root@master yaml]# vim Pc-Deployment.yaml spec: strategy: type : RollingUpdate rollingUpdate: maxSurge: 33% maxUnavailable: 33% [root@master yaml]# kubectl apply -f Pc-Deployment.yaml deployment.apps/pc-deployment configured [root@master yaml]# kubectl set image deployment pc-deployment nginx=docker.io/library/nginx:latest -n default deployment.apps/pc-deployment image updated [root@master yaml]# kubectl get pod -n default -w pc-deployment-6895856946-47gjm 1/1 Running 0 2m33s pc-deployment-6895856946-4rhkr 1/1 Running 0 2m32s pc-deployment-6895856946-6xg5w 1/1 Running 0 2m30s pc-deployment-74556686fb-7bz2k 0/1 Pending 0 0s pc-deployment-74556686fb-7bz2k 0/1 ContainerCreating 0 0s pc-deployment-74556686fb-7bz2k 1/1 Running 0 1s pc-deployment-6895856946-47gjm 1/1 Terminating 0 2m43s pc-deployment-74556686fb-xnvx5 0/1 Pending 0 0s pc-deployment-74556686fb-xnvx5 0/1 ContainerCreating 0 0s pc-deployment-74556686fb-xnvx5 1/1 Running 0 2s pc-deployment-6895856946-4rhkr 1/1 Terminating 0 2m44s pc-deployment-74556686fb-zgrss 0/1 Pending 0 0s pc-deployment-74556686fb-zgrss 0/1 ContainerCreating 0 0s pc-deployment-74556686fb-zgrss 1/1 Running 0 1s pc-deployment-6895856946-6xg5w 1/1 Terminating 0 2m43s
滚动更新的过程如下:
版本回退 在镜像更新之后,查看rs的变化,变化如下
1 2 3 4 5 6 [root@master yaml]# kubectl get rs -n default NAME DESIRED CURRENT READY AGE pc-deployment-6696798b78 0 0 0 7m37s pc-deployment-6696798b11 0 0 0 5m37s pc-deployment-c848d76789 3 3 3 72s
deployment支持版本升级过程中的暂停、继续功能以及版本回退等诸多功能,命令如下
1 2 3 4 5 6 7 kubectl rollout: 版本升级相关功能,支持下面的选项: status 显示当前升级状态 history 显示 升级历史记录 pause 暂停版本升级过程 resume 继续已经暂停的版本升级过程 restart 重启版本升级过程 undo 回滚到上一级版本(可以使用--to-revision回滚到指定版本)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 [root@master yaml ] deployment "pc-deployment" successfully rolled out [root@master yaml ] deployment.apps/pc-deployment REVISION CHANGE-CAUSE 1 kubectl create --filename=Pc-Deployment.yaml --record=true 2 kubectl create --filename=Pc-Deployment.yaml --record=true 3 kubectl create --filename=Pc-Deployment.yaml --record=true [root@master yaml ] deployment.apps/pc-deployment rolled back [root@master yaml ] NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR pc-deployment 3 /3 1 3 47m nginx docker.io/library/nginx:1.32.1 app=nginx-pod [root@master yaml ] NAME DESIRED CURRENT READY AGE pc-deployment-6696798b78 3 3 3 78m pc-deployment-966bf7f44 0 0 0 37m pc-deployment-c848d767 0 0 0 71m
金丝雀发布 Deployment控制器支持控制更新过程中的控制,如“暂停(pause)”或“继续(resume)”更新操作。比如有一批新的Pod资源创建完成后立即暂停更新过程,此时,仅存在一部分新版本的应用,主体部分还是旧的版本。然后,再筛选一小部分的用户请求路由到新版本的Pod应用,继续观察能否稳定地按期望的方式运行。确定没问题之后再继续完成余下的Pod资源滚动更新,否则立即回滚更新操作。这就是所谓的金丝雀发布。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 [root@master yaml]# kubectl set image deploy pc-deployment nginx=docker.io/library/nginx:latest -n default && kubectl rollout pause deployment pc-deployment -n default deployment.apps/pc-deployment image updated deployment.apps/pc-deployment paused [root@master yaml]# kubectl rollout status deploy pc-deployment -n default Waiting for deployment "pc-deployment" rollout to finish: 1 out of 3 new replicas have been updated... [root@master yaml]# kubectl get rs -n default -o wide NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES pc-deployment-5d89bdfbf9 2 2 2 19m nginx docker.io/library/nginx:1.32.1 pc-deployment-675d469f8b 0 0 0 14m nginx docker.io/library/nginx:latest pc-deployment-6c9f56fcfb 1 1 1 3m16s nginx docker.io/library/nginx:1.32.1 [root@master yaml]# kubectl get rs -n default -o wide NAME READY STATUS RESTARTS AGE pc-deployment-5d89bdfbf9-rj8sq 1/1 Running 0 7m33s pc-deployment-5d89bdfbf9-ttwgg 1/1 Running 0 7m35s pc-deployment-6c9f56fcfb-j2gtj 1/1 Running 0 3m31s [root@master yaml]# kubectl rollout resume deploy pc-deployment -n default deployment.apps/pc-deployment resumed [root@master yaml]# kubectl get rs -n default -o wide NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES pc-deployment-5d89bdfbf9 0 0 0 21m nginx docker.io/library/nginx:1.32.1 pc-deployment-675d469f8b 0 0 0 16m nginx docker.io/library/nginx:latest pc-deployment-6c9f56fcfb 3 3 3 5m11s nginx docker.io/library/nginx:1.32.1 [root@master yaml]# kubectl get pods -n default NAME READY STATUS RESTARTS AGE pc-deployment-6c9f56fcfb-996rt 1/1 Running 0 5m27s pc-deployment-6c9f56fcfb-7bfwh 1/1 Running 0 37s pc-deployment-6c9f56fcfb-rf84v 1/1 Running 0 37s
删除deploy 1 2 3 [root@master yaml]# kubectl delete -f Pc-Deployment.yaml deployment.apps "pc-deployment" deleted
DaemonSet(DS) 概述 DaemonSet类型的控制器可以保证在集群中的每一台(或指定)节点上都运行一个副本。一般适用于日志收集、节点监控等场景。也就是说,如果一个Pod提供的功能是节点级别的(每个节点都需要且只需要一个),那么这类Pod就适合使用DaemonSet类型的控制器创建。
特点
每当向集群中添加一个节点时,指定的 Pod 副本也将添加到该节点上
当节点从集群中移除时,Pod 也就被垃圾回收了
资源清单 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 apiVersion: apps/v1 kind: DaemonSet metadata: name: namespace: labels: spec: revisionHistoryLimit: <保留历史版本> updateStrategy: type: RollingUpdate rollingUpdate: maxUnavailable: 1 selector: matchLabels: - {key: value } matchExpressions: - {key: app , operator: In , values: [nginx-pod ]} template: metadata: labels: spec: containers: - name: image: ports:
创建DS 创建文件Pc-Daemonset.yaml,内容如下
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 apiVersion: apps/v1 kind: DaemonSet metadata: name: pc-daemonset namespace: default spec: selector: matchLabels: app: nginx-pod template: metadata: labels: app: nginx-pod spec: containers: - name: nginx image: docker.io/library/nginx:1.23.1
1 2 3 4 5 6 7 8 9 10 11 12 13 14 [root@master yaml]# kubectl create -f Pc-Daemonset.yaml daemonset.apps/pc-daemonset created [root@master yaml]# kubectl get ds -n default -o wide NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE CONTAINERS IMAGES SELECTOR pc-daemonset 2 2 2 2 2 <none> 104s nginx docker.io/library/nginx:1.23.1 app=nginx-pod [root@master yaml]# kubectl get pods -n default -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES pc-daemonset-h6q4b 1/1 Running 0 2m23s 10.244.67.78 work1.host.com <none> <none> pc-daemonset-lghrj 1/1 Running 0 2m23s 10.244.52.209 work2.host.com <none> <none>
删除DS 1 2 3 [root@master yaml ] daemonset.apps "pc-daemonset" deleted
Job 概述 Job,主要用于负责**批量处理(一次要处理指定数量任务)短暂的 一次性(每个任务仅运行一次就结束)**任务。Job特点如下:
当Job创建的pod执行成功结束时,Job将记录成功结束的pod数量
当成功结束的pod达到指定的数量时,Job将完成执行
资源清单 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 apiVersion: batch/v1 kind: Job metadata: name: namespace: labels: controller: job spec: completions: 1 parallelism: 1 activeDeadlineSeconds: <可运行时间期限> backoffLimit: 6 manualSelector: false selector: matchLabels: - {key: value } matchExpressions: - {key: app , operator: In , values: [counter-pod ]} template: metadata: labels: spec: restartPolicy: <重启策略> containers: - name: image: command:
1 2 3 4 关于重启策略设置的说明: 如果指定为OnFailure,则job会在pod出现故障时重启容器,而不是创建pod,failed次数不变 如果指定为Never,则job会在pod出现故障时创建新的pod,并且故障pod不会消失,也不会重启,failed次数加1 如果指定为Always的话,就意味着一直重启,意味着job任务会重复去执行了,当然不对,所以不能设置为Always
创建Job 创建Pc-Job.yaml,内容如下
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 apiVersion: batch/v1 kind: Job metadata: name: pc-job namespace: default spec: manualSelector: true selector: matchLabels: app: counter-pod template: metadata: labels: app: counter-pod spec: restartPolicy: Never containers: - name: counter image: docker.io/library/busybox:1.35.0 command: ["bin/sh" ,"-c" ,"for i in 9 8 7 6 5 4 3 2 1; do echo $i;sleep 3;done" ]
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 [root@master yaml]# kubectl create -f Pc-Job.yaml job.batch/pc-job created [root@master yaml]# kubectl get job -n default -o wide -w NAME COMPLETIONS DURATION AGE CONTAINERS IMAGES SELECTOR pc-job 0/1 1s 1s counter docker.io/library/busybox:1.35.0 app=counter-pod pc-job 0/1 3s 3s counter docker.io/library/busybox:1.35.0 app=counter-pod [root@master yaml]# kubectl get pod -n default -o wide -w NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES pc-job-6qwpd 1/1 Running 0 29s 10.244.67.81 work1.host.com <none> <none> pc-job-6qwpd 0/1 Completed 0 119s 10.244.67.81 work1.host.com <none> <none>
删除Job 1 2 3 [root@master yaml]# kubectl delete -f Pc-Job.yaml job.batch "pc-job" deleted
CronJob(CJ) 概述 CronJob控制器以Job控制器资源为其管控对象,并借助它管理pod资源对象,Job控制器定义的作业任务在其控制器资源创建之后便会立即执行,但CronJob可以以类似于Linux操作系统的周期性任务作业计划的方式控制其运行时间点 及重复运行 的方式。也就是说,CronJob可以在特定的时间点(反复的)去运行job任务 。
资源清单 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 apiVersion: batch/v1beta1 kind: CronJob metadata: name: namespace: labels: controller: cronjob spec: schedule: concurrencyPolicy: failedJobHistoryLimit: successfulJobHistoryLimit: startingDeadlineSeconds: jobTemplate: metadata: spec: completions: 1 parallelism: 1 activeDeadlineSeconds: 30 backoffLimit: 6 manualSelector: true selector: matchLabels: matchExpressions: 规则 - {key: app , operator: In , values: [counter-pod ]} template: metadata: labels: spec: restartPolicy: containers: - name: image: command:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 需要重点解释的几个选项: schedule: cron表达式,用于指定任务的执行时间 */1 * * * * <分钟> <小时> <日> <月份> <星期> 分钟 值从 0 到 59. 小时 值从 0 到 23. 日 值从 1 到 31. 月 值从 1 到 12. 星期 值从 0 到 6, 0 代表星期日 多个时间可以用逗号隔开; 范围可以用连字符给出;*可以作为通配符; /表示每... concurrencyPolicy: Allow: 允许Jobs并发运行(默认) Forbid: 禁止并发运行,如果上一次运行尚未完成,则跳过下一次运行 Replace: 替换,取消当前正在运行的作业并用新作业替换它
创建CJ 创建Pc-Cronjob.yaml,内容如下:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 apiVersion: batch/v1beta1 kind: CronJob metadata: name: pc-cronjob namespace: default labels: controller: cronjob spec: schedule: "*/1 * * * *" jobTemplate: metadata: spec: template: spec: restartPolicy: Never containers: - name: counter image: docker.io/library/busybox:1.35.0 command: ["bin/sh" ,"-c" ,"for i in 9 8 7 6 5 4 3 2 1; do echo $i;sleep 3;done" ]
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 [root@master yaml]# kubectl create -f Pc-Cronjob.yaml Warning: batch/v1beta1 CronJob is deprecated in v1.21+, unavailable in v1.25+; use batch/v1 CronJob cronjob.batch/pc-cronjob created [root@master yaml]# kubectl get cronjobs -n default NAME SCHEDULE SUSPEND ACTIVE LAST SCHEDULE AGE pc-cronjob */1 * * * * False 1 9s 58s [root@master yaml]# kubectl get job -n default NAME COMPLETIONS DURATION AGE pc-cronjob-27705149 0/1 2m8s 2m8s pc-cronjob-27705150 0/1 68s 68s pc-cronjob-27705151 0/1 8s 8s [root@master yaml]# kubectl get pods -n default NAME READY STATUS RESTARTS AGE pc-cronjob-27705149-kms26 0/1 Completed 0 2m37s pc-cronjob-27705150-2mvkv 0/1 Completed 0 97s pc-cronjob-27705151-dvr8c 1/1 Running 0 37s
删除CJ 1 2 3 [root@master yaml]# kubectl delete -f Pc-Cronjob.yaml Warning: batch/v1beta1 CronJob is deprecated in v1.21+, unavailable in v1.25+; use batch/v1 CronJob cronjob.batch "pc-cronjob" deleted