# 使用 CronJob 运行自动化任务

LLMS index: [llms.txt](/llms.txt)

---

<!--
title: Running Automated Tasks with a CronJob
min-kubernetes-server-version: v1.21
reviewers:
- chenopis
content_type: task
weight: 10
-->

<!-- overview -->

<!--
This page shows how to run automated tasks using Kubernetes <a class='glossary-tooltip' title='周期调度的任务（作业）。' data-bs-toggle='tooltip' data-bs-placement='top' href='/zh-cn/docs/concepts/workloads/controllers/cron-jobs/' target='_blank' aria-label='CronJob'>CronJob</a> object.
-->
本页演示如何使用 Kubernetes <a class='glossary-tooltip' title='周期调度的任务（作业）。' data-bs-toggle='tooltip' data-bs-placement='top' href='/zh-cn/docs/concepts/workloads/controllers/cron-jobs/' target='_blank' aria-label='CronJob'>CronJob</a>
对象运行自动化任务。

## 准备开始

* <!--
You need to have a Kubernetes cluster, and the kubectl command-line tool must
be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a
cluster, you can create one by using
[minikube](https://minikube.sigs.k8s.io/docs/tutorials/multi_node/)
or you can use one of these Kubernetes playgrounds:
-->
<p>你必须拥有一个 Kubernetes 的集群，且必须配置 kubectl 命令行工具让其与你的集群通信。
建议运行本教程的集群至少有两个节点，且这两个节点不能作为控制平面主机。
如果你还没有集群，你可以通过 <a href="https://minikube.sigs.k8s.io/docs/tutorials/multi_node/">Minikube</a>
构建一个你自己的集群，或者你可以使用下面的 Kubernetes 练习环境之一：</p>
<!--
* [iximiuz Labs](https://labs.iximiuz.com/playgrounds?category=kubernetes&filter=all)
* [Killercoda](https://killercoda.com/playgrounds/scenario/kubernetes)
* [KodeKloud](https://kodekloud.com/public-playgrounds)
-->
<ul>
<li><a href="https://labs.iximiuz.com/playgrounds?category=kubernetes&filter=all">iximiuz Labs</a></li>
<li><a href="https://killercoda.com/playgrounds/scenario/kubernetes">Killercoda</a></li>
<li><a href="https://kodekloud.com/public-playgrounds">KodeKloud</a></li>
</ul>


<!-- steps -->

<!--
## Creating a CronJob {#creating-a-cron-job}

Cron jobs require a config file.
Here is a manifest for a CronJob that runs a simple demonstration task every minute:
-->
## 创建 CronJob {#creating-a-cron-job}

CronJob 需要一个配置文件。
以下是针对一个 CronJob 的清单，该 CronJob 每分钟运行一个简单的演示任务：


















<div class="highlight code-sample">
    <div class="copy-code-icon">
    <a href="https://raw.githubusercontent.com/kubernetes/website/main/content/zh-cn/examples/application/job/cronjob.yaml" download="application/job/cronjob.yaml"><code>application/job/cronjob.yaml</code>
    </a><img src="/images/copycode.svg" class="icon-copycode" onclick="copyCode('application-job-cronjob-yaml')" title="复制 application/job/cronjob.yaml 到剪贴板"></img></div>
    <div class="includecode" id="application-job-cronjob-yaml"><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-yaml" data-lang="yaml"><span class="line"><span class="cl"><span class="nt">apiVersion</span><span class="p">:</span><span class="w"> </span><span class="l">batch/v1</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="nt">kind</span><span class="p">:</span><span class="w"> </span><span class="l">CronJob</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="nt">metadata</span><span class="p">:</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="w">  </span><span class="nt">name</span><span class="p">:</span><span class="w"> </span><span class="l">hello</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="nt">spec</span><span class="p">:</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="w">  </span><span class="nt">schedule</span><span class="p">:</span><span class="w"> </span><span class="s2">&#34;* * * * *&#34;</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="w">  </span><span class="nt">jobTemplate</span><span class="p">:</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="w">    </span><span class="nt">spec</span><span class="p">:</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="w">      </span><span class="nt">template</span><span class="p">:</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="w">        </span><span class="nt">spec</span><span class="p">:</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="w">          </span><span class="nt">containers</span><span class="p">:</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="w">          </span>- <span class="nt">name</span><span class="p">:</span><span class="w"> </span><span class="l">hello</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="w">            </span><span class="nt">image</span><span class="p">:</span><span class="w"> </span><span class="l">busybox:1.28</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="w">            </span><span class="nt">imagePullPolicy</span><span class="p">:</span><span class="w"> </span><span class="l">IfNotPresent</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="w">            </span><span class="nt">command</span><span class="p">:</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="w">            </span>- <span class="l">/bin/sh</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="w">            </span>- -<span class="l">c</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="w">            </span>- <span class="l">date; echo Hello from the Kubernetes cluster</span><span class="w">
</span></span></span><span class="line"><span class="cl"><span class="w">          </span><span class="nt">restartPolicy</span><span class="p">:</span><span class="w"> </span><span class="l">OnFailure</span><span class="w">
</span></span></span></code></pre></div></div>
</div>

<!--
Run the example CronJob by using this command:
-->
执行以下命令以运行此 CronJob 示例：

```shell
kubectl create -f https://k8s.io/examples/application/job/cronjob.yaml
```

<!--
The output is similar to this:
-->
输出类似于：

```
cronjob.batch/hello created
```

<!--
After creating the cron job, get its status using this command:
-->
创建好 CronJob 后，使用下面的命令来获取其状态：

```shell
kubectl get cronjob hello
```

<!--
The output is similar to this:
-->
输出类似于：

```
NAME    SCHEDULE      SUSPEND   ACTIVE   LAST SCHEDULE   AGE
hello   */1 * * * *   False     0        <none>          10s
```
<!--
As you can see from the results of the command, the cron job has not scheduled or run any jobs yet.
<a class='glossary-tooltip' title='用于以流的形式跟踪 Kubernetes 中对象变化的动词。' data-bs-toggle='tooltip' data-bs-placement='top' href='/zh-cn/docs/reference/using-api/api-concepts/#api-verbs' target='_blank' aria-label='Watch'>Watch</a> for the job to be created in around one minute:
-->
就像你从命令返回结果看到的那样，CronJob 还没有调度或执行任何任务。
等待大约一分钟，以<a class='glossary-tooltip' title='用于以流的形式跟踪 Kubernetes 中对象变化的动词。' data-bs-toggle='tooltip' data-bs-placement='top' href='/zh-cn/docs/reference/using-api/api-concepts/#api-verbs' target='_blank' aria-label='观察'>观察</a>作业的创建进程：

```shell
kubectl get jobs --watch
```

<!--
The output is similar to this:
-->
输出类似于：

```
NAME               COMPLETIONS   DURATION   AGE
hello-4111706356   0/1                      0s
hello-4111706356   0/1           0s         0s
hello-4111706356   1/1           5s         5s
```

<!--
Now you've seen one running job scheduled by the "hello" cron job.
You can stop watching the job and view the cron job again to see that it scheduled the job:
-->
现在你已经看到了一个运行中的任务被 “hello” CronJob 调度。
你可以停止监视这个任务，然后再次查看 CronJob 就能看到它调度任务：

```shell
kubectl get cronjob hello
```

<!--
The output is similar to this:
-->
输出类似于：

```
NAME    SCHEDULE      SUSPEND   ACTIVE   LAST SCHEDULE   AGE
hello   */1 * * * *   False     0        50s             75s
```

<!--
You should see that the cron job `hello` successfully scheduled a job at the time specified in
`LAST SCHEDULE`. There are currently 0 active jobs, meaning that the job has completed or failed.

Now, find the pods that the last scheduled job created and view the standard output of one of the pods.
-->
你应该能看到 `hello` CronJob 在 `LAST SCHEDULE` 声明的时间点成功地调度了一次任务。
目前有 0 个活跃的任务，这意味着任务执行完毕或者执行失败。

现在，找到最后一次调度任务创建的 Pod 并查看一个 Pod 的标准输出。

<!--
The job name is different from the pod name.
-->

<div class="alert alert-info" role="note"><h4 class="alert-heading">说明：</h4>Job 名称与 Pod 名称不同。</div>


```shell
# 在你的系统上将 "hello-4111706356" 替换为 Job 名称
pods=$(kubectl get pods --selector=job-name=hello-4111706356 --output=jsonpath={.items..metadata.name})
```

<!--
Show the pod log:
-->
查看 Pod 日志：

```shell
kubectl logs $pods
```
<!--
The output is similar to this:
-->
输出类似于：

```
Fri Feb 22 11:02:09 UTC 2019
Hello from the Kubernetes cluster
```

<!--
## Deleting a CronJob

When you don't need a cron job any more, delete it with `kubectl delete cronjob <cronjob name>`:
-->

## 删除 CronJob {#deleting-a-cronjob}

当你不再需要 CronJob 时，可以用 `kubectl delete cronjob <cronjob name>` 删掉它：

```shell
kubectl delete cronjob hello
```

<!--
Deleting the cron job removes all the jobs and pods it created and stops it from creating additional jobs.
You can read more about removing jobs in [garbage collection](/docs/concepts/architecture/garbage-collection/).
-->
删除 CronJob 会清除它创建的所有任务和 Pod，并阻止它创建额外的任务。
你可以查阅[垃圾收集](/zh-cn/docs/concepts/architecture/garbage-collection/)。
