Getting Started with k8s (2) Deployment, DaemonSet, Job, CronJob

1. Deployment use

---

Status: Available deployment completed, Progressing in progress, Complete completed, Failed Failure
reasons: Insufficient Quota, ReadingnessProbe failed, image pull failed, Limit Ranges range, application running error

1. Create nginx deploy

[root@master01 ~]# cat nginx-deploy.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:latest
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80
        
[root@master01 ~]# kubectl get pod --show-labels
NAME                                READY   STATUS    RESTARTS   AGE     LABELS
nginx-deployment-66b9f7ff85-2mqpj   1/1     Running   0          1m13s   app=nginx,pod-template-hash=66b9f7ff85
nginx-deployment-66b9f7ff85-d9rqv   1/1     Running   0          1m13s   app=nginx,pod-template-hash=66b9f7ff85
nginx-deployment-66b9f7ff85-db8fk   1/1     Running   0          1m13s   app=nginx,pod-template-hash=66b9f7ff85

2. Updated version

(1) Modify through set

[root@master01 ~]# kubectl get deployment -o wide
NAME               READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES         SELECTOR
nginx-deployment   3/3     3            3           15m   nginx        nginx:latest   app=nginx
[root@master01 ~]# kubectl set image deployment/nginx-deployment nginx=nginx:1.18
deployment.apps/nginx-deployment image updated
[root@master01 ~]# kubectl get deployment -o wide
NAME               READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES       SELECTOR
nginx-deployment   3/3     1            3           15m   nginx        nginx:1.18   app=nginx

(2) Modify through edit

[root@master01 ~]# kubectl edit deployment nginx-deployment
[root@master01 ~]# kubectl get deployment -o wide
NAME               READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES       SELECTOR
nginx-deployment   3/3     1            3           17m   nginx        nginx:1.19   app=nginx

[root@master01 ~]# kubectl rollout status deployment nginx-deployment      #查看更新状态
deployment "nginx-deployment" successfully rolled out

3. Release strategy

（1）Recreate

.This technique means that the downtime of the service depends on the shutdown and startup duration of the application

[root@master01 ~]# cat nginx-deploy.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  strategy:
    rollingUpdate:
    type: Recreate
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.19
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80

[root@master01 ~]# kubectl apply -f nginx-deploy.yaml
[root@master01 ~]# kubectl get pod -w     #开另外一个terminal查看过程

(2) Rolling update (rolling-update)

A rolling update gradually deploys a new version of an application by replacing instances one by one until all instances have been replaced.

[root@master01 ~]# cat nginx-deploy.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.19
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80

[root@master01 ~]# kubectl apply -f nginx-deploy.yaml

4. Rollback

[root@master01 ~]# kubectl set image deployment/nginx-deployment nginx=nginx:1.19  --record=true    #更新记录方便回滚
[root@master01 ~]# kubectl rollout history deployment nginx-deployment    #查看历史
deployment.apps/nginx-deployment
REVISION  CHANGE-CAUSE
2         <none>
4         <none>
7         kubectl set image deployment/nginx-deployment nginx=nginx:1.19 --record=true

[root@master01 ~]# kubectl rollout history deployment nginx-deployment --revision=7  #查看细节
deployment.apps/nginx-deployment with revision #7
Pod Template:
  Labels:       app=nginx
        pod-template-hash=6f777cb8b7
  Annotations:  kubernetes.io/change-cause: kubectl set image deployment/nginx-deployment nginx=nginx:1.19 --record=true
  Containers:
   nginx:
    Image:      nginx:1.19
    Port:       80/TCP
    Host Port:  0/TCP
    Environment:        <none>
    Mounts:     <none>
  Volumes:      <none>

[root@master01 ~]# kubectl rollout undo deployment nginx-deployment      #回滚上一个版本
[root@master01 ~]# kubectl rollout undo undo deployment nginx-deployment --to-revision=7  #回滚指定版本

5. Add comments

(1) By command

[root@master01 ~]# kubectl annotate deployments.apps nginx-deployment kubernetes.io/change-cause="image update to 1.19"   #写注释

(2) Through files

[root@master01 ~]# cat nginx-deploy.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  annotations:
    kubernetes.io/change-cause: "Image update to 1.19"
  labels:
    app: nginx
spec:
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  revisionHistoryLimit: 20
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.19
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80

[root@master01 ~]# kubectl apply -f nginx-deploy.yaml
[root@master01 ~]# kubectl describe deployment nginx-deployment

6. patch operation

[root@master01 ~]# cat nginx-deploy.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  annotations:
    kubernetes.io/change-cause: "Image update to latest"
  labels:
    app: nginx
spec:
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
  replicas: 10
  selector:
    matchLabels:
      app: nginx
  revisionHistoryLimit: 20
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:latest
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80

[root@master01 ~]# kubectl apply -f nginx-deploy.yaml
[root@master01 ~]# kubectl patch deployments.apps nginx-deployment --type=json -p='[{"op":"replace","path":"/spec/template/spec/containers/0/image","value":"nginx:1.19"}]'

[root@master01 ~]# kubectl get deployment  -owide
NAME               READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES       SELECTOR
nginx-deployment   10/10    10           10           3h    nginx        nginx:1.19   app=nginx

[root@master01 ~]# kubectl patch deployments.apps nginx-deployment -p '{"spec":{"replicas":3}}'
[root@master01 ~]# kubectl get deployment  -owide
NAME               READY   UP-TO-DATE   AVAILABLE   AGE    CONTAINERS   IMAGES       SELECTOR
nginx-deployment   3/3     3            3           3h4m   nginx        nginx:1.19   app=nginx

7. Update through different files

[root@master01 ~]# kubectl delete -f nginx-deploy.yaml
[root@master01 ~]# cat nginx-deploy-v2.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  annotations:
    kubernetes.io/change-cause: "Image update to latest"
  labels:
    app: nginx
spec:
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
  replicas: 10
  selector:
    matchLabels:
      app: nginx
  revisionHistoryLimit: 20
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.21
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80

[root@master01 ~]# kubectl delete -f nginx-deploy.yaml
[root@master01 ~]# kubectl replace -f nginx-deploy-v2.yaml

8. Copy quantity operation

• If the total is 10
• maxUnavailable: 10 - (10*25%) rounded down, the result is 8
• maxSurge = 10 + (10*25%) rounded up, the result is 13

[root@master01 ~]# kubectl apply -f nginx-deploy.yaml
[root@master01 ~]# kubectl get pod
NAME                                READY   STATUS    RESTARTS   AGE
nginx-deployment-66b9f7ff85-5cs67   1/1     Running   0          5s
nginx-deployment-66b9f7ff85-6jkq8   1/1     Running   0          5s
nginx-deployment-66b9f7ff85-6pv4x   1/1     Running   0          5s
nginx-deployment-66b9f7ff85-8s8mm   1/1     Running   0          5s
nginx-deployment-66b9f7ff85-hhv97   1/1     Running   0          5s
nginx-deployment-66b9f7ff85-htkwj   1/1     Running   0          5s
nginx-deployment-66b9f7ff85-j8h22   1/1     Running   0          5s
nginx-deployment-66b9f7ff85-k7fwn   1/1     Running   0          5s
nginx-deployment-66b9f7ff85-n7fdn   1/1     Running   0          5s
nginx-deployment-66b9f7ff85-zzsqb   1/1     Running   0          5s

[root@master01 ~]# kubectl scale deployment nginx-deployment --replicas 3
deployment.apps/nginx-deployment scaled
[root@master01 ~]# kubectl get pod
NAME                                READY   STATUS    RESTARTS   AGE
nginx-deployment-66b9f7ff85-hhv97   1/1     Running   0          92s
nginx-deployment-66b9f7ff85-j8h22   1/1     Running   0          92s
nginx-deployment-66b9f7ff85-k7fwn   1/1     Running   0          92s

[root@master01 ~]# kubectl scale deployment nginx-deployment --replicas 10
[root@master01 ~]# kubectl get pod
NAME                                READY   STATUS    RESTARTS   AGE
nginx-deployment-66b9f7ff85-6jh8k   1/1     Running   0          3s
nginx-deployment-66b9f7ff85-9dzfj   1/1     Running   0          3s
nginx-deployment-66b9f7ff85-ght2r   1/1     Running   0          3s
nginx-deployment-66b9f7ff85-hhv97   1/1     Running   0          115s
nginx-deployment-66b9f7ff85-j8h22   1/1     Running   0          115s
nginx-deployment-66b9f7ff85-k7fwn   1/1     Running   0          115s
nginx-deployment-66b9f7ff85-kp969   1/1     Running   0          3s
nginx-deployment-66b9f7ff85-w7f8t   1/1     Running   0          3s
nginx-deployment-66b9f7ff85-zhkjn   1/1     Running   0          3s
nginx-deployment-66b9f7ff85-zjmlg   1/1     Running   0          3s

2. Use of probes

---

1、readinessProbe

(1) Exec probe

[root@master01 ~]# cat read-pod.yaml
apiVersion: v1
kind: Pod
metadata:
  name: readiness
  labels:
     test: readiness
spec:
  containers:
  - name: readiness
    image: busybox:latest
    command:
    - "/bin/sh"
    - "-c"
    - "touch /tmp/healthy;sleep 30; rm -rf /tmp/healthy;sleep 100000000000"
    readinessProbe:
      exec:
        command:
        - cat
        - /tmp/healthy
      initialDelaySeconds: 10
      periodSeconds: 5

[root@master01 ~]# kubectl apply -f read-pod.yaml
[root@master01 ~]# kubectl get pod -w
[root@master01 ~]# kubectl describe pod readiness

(2) httpGet and Socket probe

[root@master01 ~]# cat nginx-deploy.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  annotations:
    kubernetes.io/change-cause: "Image update to latest"
  labels:
    app: nginx
spec:
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
  minReadySeconds: 10
  progressDeadlineSeconds: 600
  replicas: 10
  selector:
    matchLabels:
      app: nginx
  revisionHistoryLimit: 20
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:latest
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80
        readinessProbe:
          #httpGet:
          #  path: /
          #  port: 80
          #periodSeconds: 1
          tcpSocket:
            port: 80
          initialDelaySeconds: 15
          periodSeconds: 20


[root@master01 ~]# kubectl apply -f nginx-deploy.yaml
[root@master01 ~]# kubectl describe deployment nginx-deployment

2. Liveness probe

（1）Exec

[root@master01 ~]# cat live-pod.yaml
apiVersion: v1
kind: Pod
metadata:
  name: liveness
  labels:
     test: liveness
spec:
  containers:
  - name: liveness
    image: busybox:latest
    command:
    - "/bin/sh"
    - "-c"
    - "touch /tmp/healthy;sleep 30; rm -rf /tmp/healthy;sleep 100000000000"
    livenessProbe:
      exec:
        command:
        - cat
        - /tmp/healthy
      initialDelaySeconds: 10
      periodSeconds: 5

[root@master01 ~]# kubectl apply -f live-pod.yaml
[root@master01 ~]# kubectl get pod -w

(2) httpGet probe

[root@master01 ~]# cat nginx-deploy.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  annotations:
    kubernetes.io/change-cause: "Image update to latest"
  labels:
    app: nginx
spec:
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
  minReadySeconds: 10
  progressDeadlineSeconds: 600
  replicas: 10
  selector:
    matchLabels:
      app: nginx
  revisionHistoryLimit: 20
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:latest
        imagePullPolicy: IfNotPresent
        ports:
        - name: liveneess-port
          containerPort: 80
        readinessProbe:
          #httpGet:
          #  path: /
          #  port: 80
          #periodSeconds: 1
          tcpSocket:
            port: 80
          initialDelaySeconds: 15
          periodSeconds: 20

        livenessProbe:
          httpGet:
            path: /
            port: liveneess-port

[root@master01 ~]# kubectl apply -f nginx-deploy.yaml
[root@master01 ~]# kubectl describe deployment nginx-deployment

3、startupProbe

（1）httpGet

[root@master01 ~]# cat nginx-deploy.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  annotations:
    kubernetes.io/change-cause: "Image update to latest"
  labels:
    app: nginx
spec:
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
  minReadySeconds: 10
  progressDeadlineSeconds: 600
  replicas: 10
  selector:
    matchLabels:
      app: nginx
  revisionHistoryLimit: 20
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:latest
        imagePullPolicy: IfNotPresent
        ports:
        - name: liveneess-port
          containerPort: 80
        readinessProbe:
          #httpGet:
          #  path: /
          #  port: 80
          #periodSeconds: 1
          tcpSocket:
            port: 80
          initialDelaySeconds: 15
          periodSeconds: 20

        livenessProbe:
          httpGet:
            path: /
            port: liveneess-port
        startupProbe:
          httpGet:
            path: /
            port: liveneess-port
          failureThreshold: 30
          periodSeconds: 20

[root@master01 ~]# kubectl apply -f nginx-deploy.yaml
[root@master01 ~]# kubectl describe deployment nginx-deployment

(2) Rolling update

[root@master01 ~]# cat app.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: app
spec:
  minReadySeconds: 10
  selector:
    matchLabels:
      run: app
  replicas: 10
  template:
    metadata:
      labels:
        run: app
    spec:
      containers:
      - name: app
        image: busybox:latest
        args:
        - /bin/sh
        - -c
        - sleep 10; touch /tmp/healthy;sleep 100000000000
        readinessProbe:
          exec:
            command:
            - cat
            - /tmp/healthy
          initialDelaySeconds: 10
          periodSeconds: 5

[root@master01 ~]# cat app_v2.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: app
spec:
  minReadySeconds: 10
  selector:
    matchLabels:
      run: app
  replicas: 10
  template:
    metadata:
      labels:
        run: app
    spec:
      containers:
      - name: app
        image: busybox:latest
        args:
        - /bin/sh
        - -c
        - sleep 100000000000
        readinessProbe:
          exec:
            command:
            - cat
            - /tmp/healthy
          initialDelaySeconds: 10
          periodSeconds: 5

[root@master01 ~]# kubectl apply -f app.yaml
[root@master01 ~]# kubectl apply -f app_v2.yaml
[root@master01 ~]# kubectl get pod
NAME                   READY   STATUS        RESTARTS   AGE
app-6fb66c48fc-58dpt   1/1     Running       0          2m18s
app-6fb66c48fc-5sx5w   1/1     Running       0          2m18s
app-6fb66c48fc-75dtw   1/1     Running       0          2m18s
app-6fb66c48fc-79nhq   1/1     Running       0          2m18s
app-6fb66c48fc-8v9hs   1/1     Terminating   0          2m18s
app-6fb66c48fc-cgxj6   1/1     Running       0          2m18s
app-6fb66c48fc-cztkt   1/1     Running       0          2m18s
app-6fb66c48fc-f4npw   1/1     Terminating   0          2m18s
app-6fb66c48fc-g5vsv   1/1     Running       0          2m18s
app-6fb66c48fc-wjq5b   1/1     Running       0          2m18s
app-d7855499b-8lv5l    0/1     Running       0          23s
app-d7855499b-chgg9    0/1     Running       0          23s
app-d7855499b-ph7jw    0/1     Running       0          22s
app-d7855499b-q8xd7    0/1     Running       0          22s
app-d7855499b-qmqc6    0/1     Running       0          23s
[root@master01 ~]# kubectl rollout status deployment app
Waiting for deployment "app" rollout to finish: 5 out of 10 new replicas have been updated...

[root@master01 ~]# kubectl delete -f app_v2.yaml

3. DaemonSet

---

1. Deploy cAdvisor-RollingUpdate

If it is not installed on every node, you need to add tolerations
and update it through set image.

[root@master01 ~]# cat cadvisor.yaml
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: cadvisor
  labels:
    k8s-app: cadvisor
spec:
  selector:
    matchLabels:
      name: cadvisor
  updateStrategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 1
  template:
    metadata:
      labels:
        name: cadvisor
    spec:
      hostNetwork: true
      containers:
      - name: cadvisor
        image: google/cadvisor:latest
        ports:
        - containerPort: 8080
        volumeMounts:
        - name: rootfs
          mountPath: /rootfs
          readOnly: true
        - name: sys
          mountPath: /sys
          readOnly: true
        - name: containerd
          mountPath: /var/lib/containerd
          readOnly: true
        - name: disk
          mountPath: /dev/disk
          readOnly: true
      volumes:
        - name: rootfs
          hostPath:
            path: /
        - name: sys
          hostPath:
            path: /sys
        - name: containerd
          hostPath:
            path: /var/lib/containerd
        - name: disk
          hostPath:
            path: /dev/disk

[root@master01 ~]# kubectl apply -f cadvisor.yaml
[root@master01 ~]# kubectl get pod -owide
NAME             READY   STATUS    RESTARTS   AGE   IP            NODE       NOMINATED NODE   READINESS GATES
cadvisor-5mfxm   1/1     Running   0          44s   10.10.10.23   master03   <none>           <none>
cadvisor-d6mj9   1/1     Running   0          44s   10.10.10.21   master01   <none>           <none>
cadvisor-hl4nx   1/1     Running   0          44s   10.10.10.24   node01     <none>           <none>
cadvisor-w6lm4   1/1     Running   0          44s   10.10.10.22   master02   <none>           <none>
cadvisor-wcf4d   1/1     Running   0          44s   10.10.10.25   node02     <none>           <none>

[root@master01 ~]# kubectl rollout history daemonset cadvisor      #查看更新记录

2. Deploy cAdvisor-OnDelete

Update manually and delete updates yourself

[root@master01 ~]# cat cadvisor.yaml
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: cadvisor
  labels:
    k8s-app: cadvisor
spec:
  selector:
    matchLabels:
      name: cadvisor
  updateStrategy:
    type: OnDelete
  template:
    metadata:
      labels:
        name: cadvisor
    spec:
      hostNetwork: true
      containers:
      - name: cadvisor
        image: google/cadvisor:latest
        ports:
        - containerPort: 8080
        volumeMounts:
        - name: rootfs
          mountPath: /rootfs
          readOnly: true
        - name: sys
          mountPath: /sys
          readOnly: true
        - name: containerd
          mountPath: /var/lib/containerd
          readOnly: true
        - name: disk
          mountPath: /dev/disk
          readOnly: true
      volumes:
        - name: rootfs
          hostPath:
            path: /
        - name: sys
          hostPath:
            path: /sys
        - name: containerd
          hostPath:
            path: /var/lib/containerd
        - name: disk
          hostPath:
            path: /dev/disk

[root@master01 ~]# kubectl apply -f cadvisor.yaml
[root@master01 ~]# kubectl delete -f cadvisor.yaml

4. Job and CronJob

---

1. First experience of Job

restartPolicy: always, Never, OnFailure
Never: If an error occurs, new pods will be created continuously, which will exhaust resources. You can pass backoffLimit: limit the maximum number of times activeDeadlineSeconds: how many seconds to delete ttlSecondsAfterFinished: cleanup failure or successful job time

[root@master01 ~]# cat myjob.yaml
apiVersion: batch/v1
kind: Job
metadata:
  name: myjob
spec:
  backoffLimit: 3
  activeDeadlineSeconds: 10
  ttlSecondsAfterFinished: 30
  template:
    spec:
      containers:
      - name: myjob
        image: busybox
        command: ["echo","hello world!"]
      restartPolicy: Never
[root@master01 ~]# cat myjob.yaml
apiVersion: batch/v1
kind: Job
metadata:
  name: myjob
spec:
  backoffLimit: 3
  activeDeadlineSeconds: 10
  ttlSecondsAfterFinished: 30
  template:
    spec:
      containers:
      - name: myjob
        image: busybox
        command: ["echo","hello world!"]
      restartPolicy: Never

[root@master01 ~]# kubectl apply -f myjob.yaml
[root@master01 ~]# kubectl get pod
NAME          READY   STATUS      RESTARTS   AGE
myjob-cqmxf   0/1     Completed   0          19s

[root@master01 ~]# kubectl get jobs myjob
NAME    COMPLETIONS   DURATION   AGE
myjob   1/1           5s         2m1s

[root@master01 ~]# kubectl logs myjob-cqmxf
hello world!

[root@master01 ~]# kubectl delete -f myjob.yaml

(2) Run 2 at the same time

completions: total amount of execution

[root@master01 ~]# cat myjob.yaml
apiVersion: batch/v1
kind: Job
metadata:
  name: myjob
spec:
  parallelism: 2
  completions: 10
  completionMode: Indexed
  backoffLimit: 3
  activeDeadlineSeconds: 120
  ttlSecondsAfterFinished: 1200
  template:
    spec:
      containers:
      - name: myjob
        image: busybox
        command: ["echo","hello world!"]
      restartPolicy: Never

[root@master01 ~]# kubectl apply -f myjob.yaml

2. First experience with CronJob

Set time zone: timeZone: Etc/UTC

[root@master01 ~]# cat cronjob.yaml
apiVersion: batch/v1
kind: CronJob
metadata:
  name: hello
spec:
  schedule: "*/1 * * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: hello
            image: busybox
            command: ["echo","hello world!"]
          restartPolicy: OnFailure
          
[root@master01 ~]# kubectl apply -f cronjob.yaml

3. CronJob setting parameters

  successfulJobsHistoryLimit: 3    #记录成功次数3
  failedJobsHistoryLimit: 3        #记录失败次数3
  startingDeadlineSeconds: 200     #最晚执行时间
  concurrencyPolicy: Allow         #允许叠加，Forbid忽略旧任务 Replace忽略新任务 

[root@master01 ~]# cat cronjob.yaml
apiVersion: batch/v1
kind: CronJob
metadata:
  name: hello
spec:
  successfulJobsHistoryLimit: 3
  failedJobsHistoryLimit: 3
  startingDeadlineSeconds: 200
  concurrencyPolicy: Allow
  schedule: "*/1 * * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: hello
            image: busybox
            command: ["echo","hello world!"]
          restartPolicy: OnFailure

[root@master01 ~]# kubectl apply -f cronjob.yaml