首页 > 解决方案 > Kubernetes pod 计划重启而不会停机

问题描述

我有 6 个 Pod 副本正在运行,我想每 5 分钟重新启动\重新创建一次。

这需要进行滚动更新——这样所有更新都不会立即终止,也不会出现停机时间。我如何实现这一目标?

我尝试使用 cron 作业,但似乎没有工作:

apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: scheduled-pods-recreate
spec:
  schedule: "*/5 * * * *"
  concurrencyPolicy: Forbid
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: ja-engine
            image: app-image
            imagePullPolicy: IfNotPresent
          restartPolicy: OnFailure

尽管该作业已成功创建并按照以下说明进行了安排,但它似乎从未运行过:

Name:                       scheduled-pods-recreate
Namespace:                  jk-test
Labels:                     <none>
Annotations:                <none>
Schedule:                   */5 * * * *
Concurrency Policy:         Forbid
Suspend:                    False
Starting Deadline Seconds:  <unset>
Selector:                   <unset>
Parallelism:                <unset>
Completions:                <unset>
Pod Template:
  Labels:  <none>
  Containers:
   ja-engine:
    Image:           image_url
    Port:            <none>
    Host Port:       <none>
    Environment:     <none>
    Mounts:          <none>
  Volumes:           <none>
Last Schedule Time:  Tue, 19 Feb 2019 10:10:00 +0100
Active Jobs:         scheduled-pods-recreate-1550567400
Events:
  Type    Reason            Age   From                Message
  ----    ------            ----  ----                -------
  Normal  SuccessfulCreate  23m   cronjob-controller  Created job scheduled-pods-recreate-1550567400

所以首先,我如何确保它正在运行以便重新创建 pod?

另外我怎样才能确保没有停机时间?

cronjob 的更新版本:

apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: hello
spec:
  schedule: "*/1 * * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: hello
            image: busybox
            args:
            - /bin/sh
            - -c
            - kubectl patch deployment runners -p '{"spec":{"template":{"spec":{"containers":[{"name":"jp-runner","env":[{"name":"START_TIME","value":"'$(date +%s)'"}]}]}}}}' -n jp-test
          restartPolicy: OnFailure

Pod 没有以消息 Back-off restarting failed container 和错误开始,如下所示:

State:          Terminated
      Reason:       Error
      Exit Code:    127

标签: kuberneteskubernetes-helmkubernetes-cronjob

解决方案


从 Kubernetes 1.15 开始,您可以使用以下命令执行滚动重启。

kubectl rollout restart deployment <deployment name>

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