Merge pull request #36615 from yanrongshi/zh-cn]Sync-docs/tasks/inject-data-application/downward-api-volume-expose-pod-information.md

[zh-cn] Sync 2 files in tasks/inject-data-application/

Author: k8s-ci-robot

content/zh-cn/docs/tasks/inject-data-application/downward-api-volume-expose-pod-information.md

@@ -20,7 +20,7 @@ A `downwardAPI` volume can expose Pod fields and container fields.
 <!--
 In Kubernetes, there are two ways to expose Pod and container fields to a running container:
 
-* [Environment variables](/docs/tasks/inject-data-application/environment-variable-expose-pod-information/#the-downward-api)
+* [Environment variables](/docs/tasks/inject-data-application/environment-variable-expose-pod-information/)
 * Volume files, as explained in this task
 
 Together, these two ways of exposing Pod and container fields are called the
@@ -75,7 +75,7 @@ field should be stored in a file named `annotations`.
 
 <!--
 The fields in this example are Pod fields. They are not
-fields of the Container in the Pod.
+fields of the container in the Pod.
 -->
 {{< note >}}
 本示例中的字段是 Pod 字段，不是 Pod 中容器的字段。

content/zh-cn/docs/tasks/inject-data-application/environment-variable-expose-pod-information.md

@@ -12,66 +12,63 @@ weight: 30
 
 <!--
 This page shows how a Pod can use environment variables to expose information
-about itself to Containers running in the Pod. Environment variables can expose
-Pod fields and Container fields.
+about itself to containers running in the Pod, using the _downward API_.
+You can use environment variables to expose Pod fields, container fields, or both.
 -->
-此页面展示 Pod 如何使用环境变量把自己的信息呈现给 Pod 中运行的容器。
-环境变量可以呈现 Pod 的字段和容器字段。
+此页面展示 Pod 如何使用环境变量把自身的信息呈现给 Pod 中运行的容器。
+使用 **downward API** 你可以使用环境变量来呈现 Pod 的字段、容器字段或两者。
 
-## {{% heading "prerequisites" %}}
+<!--
+In Kubernetes, there are two ways to expose Pod and container fields to a running container:
 
-{{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
+* _Environment variables_, as explained in this task
+* [Volume files](/docs/tasks/inject-data-application/downward-api-volume-expose-pod-information/)
 
-<!-- steps -->
+Together, these two ways of exposing Pod and container fields are called the
+downward API.
+-->
+在 Kubernetes 中有两种方式可以将 Pod 和 容器字段呈现给运行中的容器：
 
-## Downward API
+* 如本任务所述的**环境变量**。
+* [卷文件](/zh-cn/docs/tasks/inject-data-application/downward-api-volume-expose-pod-information/)
 
-<!--
-There are two ways to expose Pod and Container fields to a running Container:
+这两种呈现 Pod 和 容器字段的方式统称为 downward API。
 
-* Environment variables
-* [Volume Files](/docs/tasks/inject-data-application/downward-api-volume-expose-pod-information/#the-downward-api)
 
-Together, these two ways of exposing Pod and Container fields are called the
-*Downward API*.
--->
-
-有两种方式可以将 Pod 和 Container 字段呈现给运行中的容器：
+## {{% heading "prerequisites" %}}
 
-* 环境变量
-* [卷文件](/zh-cn/docs/tasks/inject-data-application/downward-api-volume-expose-pod-information/#the-downward-api)
+{{< include "task-tutorial-prereqs.md" >}}
 
-这两种呈现 Pod 和 Container 字段的方式统称为 *Downward API*。
+<!-- steps -->
 
 <!--
 ## Use Pod fields as values for environment variables
 
-In this exercise, you create a Pod that has one Container. Here is the
-configuration file for the Pod:
+In this part of exercise, you create a Pod that has one container, and you
+project Pod-level fields into the running container as environment variables.
 -->
 ## 用 Pod 字段作为环境变量的值
 
-在这个练习中，你将创建一个包含一个容器的 Pod。这是该 Pod 的配置文件：
+在这部分练习中，你将创建一个包含一个容器的 Pod。并将 Pod 级别的字段作为环境变量映射到正在运行的容器中。
 
 {{< codenew file="pods/inject/dapi-envars-pod.yaml" >}}
 
 <!--
-In the configuration file, you can see five environment variables. The `env`
+In that manifest, you can see five environment variables. The `env`
 field is an array of
-[EnvVars](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#envvar-v1-core).
+environment variable definitions.
 The first element in the array specifies that the `MY_NODE_NAME` environment
 variable gets its value from the Pod's `spec.nodeName` field. Similarly, the
 other environment variables get their names from Pod fields.
 -->
-这个配置文件中，你可以看到五个环境变量。`env` 字段是一个
-[EnvVars](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#envvar-v1-core).
-对象的数组。
+这个清单中，你可以看到五个环境变量。`env` 字段定义了一组环境变量。
+
 数组中第一个元素指定 `MY_NODE_NAME` 这个环境变量从 Pod 的 `spec.nodeName` 字段获取变量值。
 同样，其它环境变量也是从 Pod 的字段获取它们的变量值。
 
 <!--
 The fields in this example are Pod fields. They are not fields of the
-Container in the Pod.
+container in the Pod.
 -->
 {{< note >}}
 本示例中的字段是 Pod 字段，不是 Pod 中 Container 的字段。
@@ -91,16 +88,17 @@ Verify that the Container in the Pod is running:
 -->
 验证 Pod 中的容器运行正常：
 
-```
+```shell
+# 如果新创建的 Pod 还是处于不健康状态，请重新运行此命令几次。
 kubectl get pods
 ```
 
 <!--
-View the Container's logs:
+View the container's logs:
 -->
 查看容器日志：
 
-```
+```shell
 kubectl logs dapi-envars-fieldref
 ```
 
@@ -119,17 +117,17 @@ default
 
 <!--
 To see why these values are in the log, look at the `command` and `args` fields
-in the configuration file. When the Container starts, it writes the values of
+in the configuration file. When the container starts, it writes the values of
 five environment variables to stdout. It repeats this every ten seconds.
 
-Next, get a shell into the Container that is running in your Pod:
+Next, get a shell into the container that is running in your Pod:
 -->
-要了解为什么这些值在日志中，请查看配置文件中的`command` 和 `args`字段。
-当容器启动时，它将五个环境变量的值写入 stdout。每十秒重复执行一次。
+要了解为什么这些值出现在日志中，请查看配置文件中的 `command` 和 `args` 字段。
+当容器启动时，它将五个环境变量的值写入标准输出。每十秒重复执行一次。
 
 接下来，通过打开一个 Shell 进入 Pod 中运行的容器：
 
-```
+```shell
 kubectl exec -it dapi-envars-fieldref -- sh
 ```
 
@@ -138,8 +136,9 @@ In your shell, view the environment variables:
 -->
 在 Shell 中，查看环境变量：
 
-```
-/# printenv
+```shell
+# 在容器内的 `shell` 中运行
+printenv
 ```
 
 <!--
@@ -160,42 +159,41 @@ MY_POD_NAME=dapi-envars-fieldref
 ```
 
 <!--
-## Use Container fields as values for environment variables
+## Use container fields as values for environment variables
+
+In the preceding exercise, you used information from Pod-level fields as the values
+for environment variables.
+In this next exercise, you are going to pass fields that are part of the Pod
+definition, but taken from the specific
+[container](/docs/reference/kubernetes-api/workload-resources/pod-v1/#Container)
+rather than from the Pod overall.
+
+Here is a manifest for another Pod that again has just one container:
 
-In the preceding exercise, you used Pod fields as the values for environment
-variables. In this next exercise, you use Container fields as the values for
-environment variables. Here is the configuration file for a Pod that has one
-container:
 -->
-## 用 Container 字段作为环境变量的值
+## 使用容器字段作为环境变量的值
+
+前面的练习中，你将 Pod 级别的字段作为环境变量的值。
+接下来这个练习中，你将传递属于 Pod 定义的字段，但这些字段取自特定容器而不是整个 Pod。
 
-前面的练习中，你将 Pod 字段作为环境变量的值。
-接下来这个练习中，你将用 Container 字段作为环境变量的值。这里是包含一个容器的 Pod 的配置文件：
+这里是只包含一个容器的 Pod 的清单：
 
 {{< codenew file="pods/inject/dapi-envars-container.yaml" >}}
 
 <!--
-In the configuration file, you can see four environment variables. The `env`
+In this manifest, you can see four environment variables. The `env`
 field is an array of
-[EnvVars](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#envvar-v1-core).
+environment variable definitions.
 The first element in the array specifies that the `MY_CPU_REQUEST` environment
-variable gets its value from the `requests.cpu` field of a Container named
+variable gets its value from the `requests.cpu` field of a container named
 `test-container`. Similarly, the other environment variables get their values
-from Container fields.
-
-The fields in this example are Pod fields. They are not fields of the
-Container in the Pod.
+from fields that are specific to this container.
 
 Create the Pod:
 -->
-这个配置文件中，你可以看到四个环境变量。`env` 字段是一个
-[EnvVars](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#envvar-v1-core).
-对象的数组。数组中第一个元素指定 `MY_CPU_REQUEST` 这个环境变量从 Container 的 `requests.cpu`
-字段获取变量值。同样，其它环境变量也是从 Container 的字段获取它们的变量值。
-
-{{< note >}}
-本例中使用的是 Container 的字段而不是 Pod 的字段。
-{{< /note >}}
+这个清单中，你可以看到四个环境变量。`env` 字段定义了一组环境变量。
+数组中第一个元素指定 `MY_CPU_REQUEST` 这个环境变量从容器的 `requests.cpu`
+字段获取变量值。同样，其它的环境变量也是从特定于这个容器的字段中获取它们的变量值。
 
 创建Pod：
 
@@ -204,20 +202,21 @@ kubectl apply -f https://k8s.io/examples/pods/inject/dapi-envars-container.yaml
 ```
 
 <!--
-Verify that the Container in the Pod is running:
+Verify that the container in the Pod is running:
 -->
 验证 Pod 中的容器运行正常：
 
-```
+```shell
+# 如果新创建的 Pod 还是处于不健康状态，请重新运行此命令几次。
 kubectl get pods
 ```
 
 <!--
-View the Container's logs:
+View the container's logs:
 -->
 查看容器日志：
 
-```
+```shell
 kubectl logs dapi-envars-resourcefieldref
 ```
 
@@ -236,16 +235,29 @@ The output shows the values of selected environment variables:
 ## {{% heading "whatsnext" %}}
 
 <!--
-* [Defining Environment Variables for a Container](/docs/tasks/inject-data-application/define-environment-variable-container/)
+* Read [Defining Environment Variables for a Container](/docs/tasks/inject-data-application/define-environment-variable-container/)
+* Read the [`spec`](/docs/reference/kubernetes-api/workload-resources/pod-v1/#PodSpec)
+  API definition for Pod. This includes the definition of Container (part of Pod).
+* Read the list of [available fields](/docs/concepts/workloads/pods/downward-api/#available-fields) that you
+  can expose using the downward API.
+-->
+* 阅读[给容器定义环境变量](/zh-cn/docs/tasks/inject-data-application/define-environment-variable-container/)
+* 阅读 Pod 的 [`spec`](/zh-cn/docs/reference/kubernetes-api/workload-resources/pod-v1/#PodSpec)
+  API 包括容器（Pod 的一部分）的定义。
+* 阅读可以使用 downward API 公开的[可用字段](/zh-cn/docs/concepts/workloads/pods/downward-api/#available-fields)列表。
+
+<!--
+Read about Pods, containers and environment variables in the legacy API reference:
+
 * [PodSpec](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#podspec-v1-core)
 * [Container](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#container-v1-core)
 * [EnvVar](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#envvar-v1-core)
 * [EnvVarSource](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#envvarsource-v1-core)
 * [ObjectFieldSelector](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#objectfieldselector-v1-core)
 * [ResourceFieldSelector](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#resourcefieldselector-v1-core)
 -->
+在旧版 API 参考中阅读有关 Pod、容器和环境变量的信息：
 
-* [给容器定义环境变量](/zh-cn/docs/tasks/inject-data-application/define-environment-variable-container/)
 * [PodSpec](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#podspec-v1-core)
 * [Container](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#container-v1-core)
 * [EnvVar](/docs/reference/generated/kubernetes-api/{{< param "version" >}}/#envvar-v1-core)