---
title: 使用Deployment运行一个无状态应用
content_type: tutorial
---

<!-- overview -->

<!--
This page shows how to run an application using a Kubernetes Deployment object.
-->
本文介绍通过Kubernetes Deployment对象如何去运行一个应用.

## {{% heading "objectives" %}}

<!--
* Create an nginx deployment.
* Use kubectl to list information about the deployment.
* Update the deployment.
-->
* 创建一个 nginx Deployment.
* 使用 kubectl 列举关于 Deployment 的信息.
* 更新 Deployment。

## {{% heading "prerequisites" %}}

{{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}

<!-- lessoncontent -->

<!--
## Creating and exploring an nginx deployment

You can run an application by creating a Kubernetes Deployment object, and you
can describe a Deployment in a YAML file. For example, this YAML file describes
a Deployment that runs the nginx:1.14.2 Docker image:
-->
## 创建并了解一个 nginx Deployment

你可以通过创建一个 Kubernetes Deployment 对象来运行一个应用, 且你可以在一个
YAML 文件中描述 Deployment。例如, 下面这个 YAML 文件描述了一个运行 nginx:1.14.2
Docker 镜像的 Deployment：

{{< codenew file="application/deployment.yaml" >}}

<!--
1. Create a Deployment based on the YAML file:
-->
1. 通过 YAML 文件创建一个 Deployment：

   ```shell
   kubectl apply -f https://k8s.io/examples/application/deployment.yaml
   ```

<!--
1. Display information about the Deployment:
-->
2. 显示 Deployment 相关信息：

   ```shell
   kubectl describe deployment nginx-deployment
   ```

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

   ```
   Name:     nginx-deployment
   Namespace:    default
   CreationTimestamp:  Tue, 30 Aug 2016 18:11:37 -0700
   Labels:     app=nginx
   Annotations:    deployment.kubernetes.io/revision=1
   Selector:   app=nginx
   Replicas:   2 desired | 2 updated | 2 total | 2 available | 0 unavailable
   StrategyType:   RollingUpdate
   MinReadySeconds:  0
   RollingUpdateStrategy:  1 max unavailable, 1 max surge
   Pod Template:
     Labels:       app=nginx
     Containers:
      nginx:
       Image:              nginx:1.7.9
       Port:               80/TCP
       Environment:        <none>
       Mounts:             <none>
     Volumes:              <none>
   Conditions:
     Type          Status  Reason
     ----          ------  ------
     Available     True    MinimumReplicasAvailable
     Progressing   True    NewReplicaSetAvailable
   OldReplicaSets:   <none>
   NewReplicaSet:    nginx-deployment-1771418926 (2/2 replicas created)
   No events.
   ```

<!--
1. List the Pods created by the deployment:
-->
3. 列出 Deployment 创建的 Pods：

   ```shell
   kubectl get pods -l app=nginx
   ```

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

   ```
   NAME                                READY     STATUS    RESTARTS   AGE
   nginx-deployment-1771418926-7o5ns   1/1       Running   0          16h
   nginx-deployment-1771418926-r18az   1/1       Running   0          16h
   ```

<!--
1. Display information about a Pod:
-->
4. 展示某一个 Pod 信息：

   ```shell
   kubectl describe pod <pod-name>
   ```

   <!--
   where `<pod-name>` is the name of one of your Pods.
   -->
   这里的 `<pod-name>` 是某一 Pod 的名称。

<!--
## Updating the deployment

You can update the deployment by applying a new YAML file. This YAML file
specifies that the deployment should be updated to use nginx 1.16.1.
-->
## 更新 Deployment

你可以通过更新一个新的 YAML 文件来更新 Deployment。下面的 YAML 文件指定该
Deployment 镜像更新为 nginx 1.16.1。

{{< codenew file="application/deployment-update.yaml" >}}

<!--
1. Apply the new YAML file:
-->
1. 应用新的 YAML：

   ```shell
   kubectl apply -f https://k8s.io/examples/application/deployment-update.yaml
   ```

<!--
1. Watch the deployment create pods with new names and delete the old pods:
-->
2. 查看该 Deployment 以新的名称创建 Pods 同时删除旧的 Pods：

   ```shell
   kubectl get pods -l app=nginx
   ```
<!--
## Scaling the application by increasing the replica count

You can increase the number of Pods in your Deployment by applying a new YAML
file. This YAML file sets `replicas` to 4, which specifies that the Deployment
should have four Pods:
-->
## 通过增加副本数来扩缩应用

你可以通过应用新的 YAML 文件来增加 Deployment 中 Pods 的数量。
下面的 YAML 文件将 `replicas` 设置为 4，指定该 Deployment 应有 4 个 Pods：

{{< codenew file="application/deployment-scale.yaml" >}}

<!--
1. Apply the new YAML file:
-->
1. 应用新的 YAML 文件：

   ```shell
   kubectl apply -f https://k8s.io/examples/application/deployment-scale.yaml
   ```

<!--
1. Verify that the Deployment has four Pods:
-->
2. 验证 Deployment 有 4 个 Pods：

   ```shell
   kubectl get pods -l app=nginx
   ```

   <!--
   The output is similar to this:
   -->
   输出的结果类似于:

   ```
   NAME                               READY     STATUS    RESTARTS   AGE
   nginx-deployment-148880595-4zdqq   1/1       Running   0          25s
   nginx-deployment-148880595-6zgi1   1/1       Running   0          25s
   nginx-deployment-148880595-fxcez   1/1       Running   0          2m
   nginx-deployment-148880595-rwovn   1/1       Running   0          2m
   ```

<!--
## Deleting a deployment

Delete the deployment by name:
-->
## 删除 Deployment

通过名称删除 Deployment：

```shell
kubectl delete deployment nginx-deployment
```

<!--
## ReplicationControllers -- the Old Way

The preferred way to create a replicated application is to use a Deployment,
which in turn uses a ReplicaSet. Before the Deployment and ReplicaSet were
added to Kubernetes, replicated applications were configured using a
[ReplicationController](/docs/concepts/workloads/controllers/replicationcontroller/).
-->
## ReplicationControllers -- 旧的方式

创建一个多副本应用首选方法是使用 Deployment，Deployment 内部使用 ReplicaSet。
在 Deployment 和 ReplicaSet 被引入到 Kubernetes 之前，多副本应用通过
[ReplicationController](/zh/docs/concepts/workloads/controllers/replicationcontroller/)
来配置。

## {{% heading "whatsnext" %}}

<!--
* Learn more about [Deployment objects](/docs/concepts/workloads/controllers/deployment/).
-->
* 进一步了解 [Deployment 对象](/zh/docs/concepts/workloads/controllers/deployment/)。

