diff --git a/docs/tasks/inject-data-application/environment-variable-expose-pod-information-2017-9-15.md b/docs/tasks/inject-data-application/environment-variable-expose-pod-information-2017-9-15.md deleted file mode 100755 index 391b58ee5..000000000 --- a/docs/tasks/inject-data-application/environment-variable-expose-pod-information-2017-9-15.md +++ /dev/null @@ -1,176 +0,0 @@ ---- -title: Expose Pod Information to Containers Through Environment Variables ---- - -{% capture overview %} - -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. - -There are two ways to expose Pod and Container fields to a running Container: -environment variables and -[DownwardAPIVolumeFiles](/docs/resources-reference/{{page.version}}/#downwardapivolumefile-v1-core). -Together, these two ways of exposing Pod and Container fields are called the -*Downward API*. - -{% endcapture %} - - -{% capture prerequisites %} - -{% include task-tutorial-prereqs.md %} - -{% endcapture %} - - -{% capture steps %} - -## The Downward API - -There are two ways to expose Pod and Container fields to a running Container: - -* Environment variables -* [DownwardAPIVolumeFiles](/docs/resources-reference/{{page.version}}/#downwardapivolumefile-v1-core) - -Together, these two ways of exposing Pod and Container fields are called the -*Downward API*. - - -## 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: - -{% include code.html language="yaml" file="dapi-envars-pod.yaml" ghlink="/docs/tasks/inject-data-application/dapi-envars-pod.yaml" %} - -In the configuration file, you can see five environment variables. The `env` -field is an array of -[EnvVars](/docs/resources-reference/{{page.version}}/#envvar-v1-core). -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. - -**Note:** The fields in this example are Pod fields. They are not fields of the -Container in the Pod. -{: .note} - -Create the Pod: - -```shell -kubectl create -f https://k8s.io/docs/tasks/inject-data-application/dapi-envars-pod.yaml -``` - -Verify that the Container in the Pod is running: - -``` -kubectl get pods -``` - -View the Container's logs: - -``` -kubectl logs dapi-envars-fieldref -``` - -The output shows the values of selected environment variables: - -``` -minikube -dapi-envars-fieldref -default -172.17.0.4 -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 -five environment variables to stdout. It repeats this every ten seconds. - -Next, get a shell into the Container that is running in your Pod: - -``` -kubectl exec -it dapi-envars-fieldref -- sh -``` - -In your shell, view the environment variables: - -``` -/# printenv -``` - -The output shows that certain environment variables have been assigned the -values of Pod fields: - -``` -MY_POD_SERVICE_ACCOUNT=default -... -MY_POD_NAMESPACE=default -MY_POD_IP=172.17.0.4 -... -MY_NODE_NAME=minikube -... -MY_POD_NAME=dapi-envars-fieldref -``` - -## Use Container fields as values for environment variables - -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: - -{% include code.html language="yaml" file="dapi-envars-container.yaml" ghlink="/docs/tasks/inject-data-application/dapi-envars-container.yaml" %} - -In the configuration file, you can see four environment variables. The `env` -field is an array of -[EnvVars](/docs/resources-reference/{{page.version}}/#envvar-v1-core). -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 -`test-container`. Similarly, the other environment variables get their values -from Container fields. - -Create the Pod: - -```shell -kubectl create -f https://k8s.io/docs/tasks/inject-data-application/dapi-envars-container.yaml -``` - -Verify that the Container in the Pod is running: - -``` -kubectl get pods -``` - -View the Container's logs: - -``` -kubectl logs dapi-envars-resourcefieldref -``` - -The output shows the values of selected environment variables: - -``` -1 -1 -33554432 -67108864 -``` - -{% endcapture %} - -{% capture whatsnext %} - -* [Defining Environment Variables for a Container](/docs/tasks/configure-pod-container/define-environment-variable-container/) -* [PodSpec](/docs/resources-reference/{{page.version}}/#podspec-v1-core) -* [Container](/docs/resources-reference/{{page.version}}/#container-v1-core) -* [EnvVar](/docs/resources-reference/{{page.version}}/#envvar-v1-core) -* [EnvVarSource](/docs/resources-reference/{{page.version}}/#envvarsource-v1-core) -* [ObjectFieldSelector](/docs/resources-reference/{{page.version}}/#objectfieldselector-v1-core) -* [ResourceFieldSelector](/docs/resources-reference/{{page.version}}/#resourcefieldselector-v1-core) - -{% endcapture %} - - -{% include templates/task.md %} - diff --git a/docs/tasks/inject-data-application/environment-variable-expose-pod-information.md b/docs/tasks/inject-data-application/environment-variable-expose-pod-information.md index 391b58ee5..e67f9eb87 100755 --- a/docs/tasks/inject-data-application/environment-variable-expose-pod-information.md +++ b/docs/tasks/inject-data-application/environment-variable-expose-pod-information.md @@ -1,18 +1,22 @@ --- +title: 通过环境变量向容器暴露 Pod 信息 +cn-approvers: +- chentao1596 +--- + {% capture overview %} + +本页展示了 Pod 如何使用环境变量向 Pod 中运行的容器暴露有关自身的信息。环境变量可以暴露 Pod 字段和容器字段。 {% endcapture %} @@ -26,54 +30,90 @@ Together, these two ways of exposing Pod and Container fields are called the {% capture steps %} + +## Downward API + +有两种方式将 Pod 和容器字段暴露给运行中的容器： + +* 环境变量 +* [DownwardAPIVolumeFiles](/docs/api-reference/{{page.version}}/#downwardapivolumefile-v1-core) + +这两种暴露 Pod 和容器字段的方式被称为 *Downward API*。 - + +## 使用 Pod 字段作为环境变量的值 + +在本练习中，您将创建一个有一个容器的 Pod。下面是POD的配置文件： {% include code.html language="yaml" file="dapi-envars-pod.yaml" ghlink="/docs/tasks/inject-data-application/dapi-envars-pod.yaml" %} + +在配置文件中，您可以看到五个环境变量。`env` 字段是 [EnvVars](/docs/api-reference/{{page.version}}/#envvar-v1-core) 的数组。数组中的第一个元素指定 `MY_NODE_NAME` 环境变量从 Pod 的 `spec.nodeName` 字段中获取其值。类似地，其他环境变量从 Pod 字段中获取它们的名称。 + +**注意：** 示例中的字段是 Pod 的字段。它们不是 Pod 中的容器的字段。 {: .note} + +创建 Pod： ```shell kubectl create -f https://k8s.io/docs/tasks/inject-data-application/dapi-envars-pod.yaml ``` + +验证 Pod 中的容器是 running 状态： ``` kubectl get pods ``` + +查看容器日志： ``` kubectl logs dapi-envars-fieldref ``` + +输出显示选定的环境变量的值： ``` minikube @@ -83,24 +123,36 @@ default default ``` + +想要知道为什么这些值会打印在日志中，请查看配置文件的 `command` 和 `args` 字段。当容器启动时，它将 5 个环境变量的值写到标准输出中。每十秒钟重复一次。 + +接下来，将一个 shell 放入正在您的 Pod 中运行的容器里面： ``` kubectl exec -it dapi-envars-fieldref -- sh ``` + +在 shell 中，查看环境变量： ``` /# printenv ``` + +输出结果显示，某些环境变量已被指定为 Pod 字段的值： ``` MY_POD_SERVICE_ACCOUNT=default @@ -113,42 +165,63 @@ MY_NODE_NAME=minikube MY_POD_NAME=dapi-envars-fieldref ``` + +## 使用容器字段作为环境变量的值 + +在前面的练习中，您使用 Pod 字段作为环境变量的值。在下一个练习中，您将使用容器字段用作环境变量的值。下面是一个 Pod 的配置文件，其中包含一个容器： {% include code.html language="yaml" file="dapi-envars-container.yaml" ghlink="/docs/tasks/inject-data-application/dapi-envars-container.yaml" %} + +在配置文件中，您可以看到四个环境变量。`env` 字段是 [EnvVars](/docs/api-reference/{{page.version}}/#envvar-v1-core) 的数组。数组中的第一个元素指定 `MY_CPU_REQUEST` 环境变量从名为 `test-container` 的容器的 `requests.cpu` 字段中获取其值。类似地，其他环境变量从容器字段中获取它们的值。 + +创建 Pod： ```shell kubectl create -f https://k8s.io/docs/tasks/inject-data-application/dapi-envars-container.yaml ``` + +验证 Pod 中的容器是 running 状态： ``` kubectl get pods ``` + +查看容器日志： ``` kubectl logs dapi-envars-resourcefieldref ``` + +输出展示了选定环境变量的值： ``` 1 @@ -161,13 +234,16 @@ The output shows the values of selected environment variables: {% capture whatsnext %} -* [Defining Environment Variables for a Container](/docs/tasks/configure-pod-container/define-environment-variable-container/) -* [PodSpec](/docs/resources-reference/{{page.version}}/#podspec-v1-core) -* [Container](/docs/resources-reference/{{page.version}}/#container-v1-core) -* [EnvVar](/docs/resources-reference/{{page.version}}/#envvar-v1-core) -* [EnvVarSource](/docs/resources-reference/{{page.version}}/#envvarsource-v1-core) -* [ObjectFieldSelector](/docs/resources-reference/{{page.version}}/#objectfieldselector-v1-core) -* [ResourceFieldSelector](/docs/resources-reference/{{page.version}}/#resourcefieldselector-v1-core) + +* [为容器定义环境变量](/docs/tasks/inject-data-application/define-environment-variable-container/) +* [PodSpec](/docs/api-reference/{{page.version}}/#podspec-v1-core) +* [Container](/docs/api-reference/{{page.version}}/#container-v1-core) +* [EnvVar](/docs/api-reference/{{page.version}}/#envvar-v1-core) +* [EnvVarSource](/docs/api-reference/{{page.version}}/#envvarsource-v1-core) +* [ObjectFieldSelector](/docs/api-reference/{{page.version}}/#objectfieldselector-v1-core) +* [ResourceFieldSelector](/docs/api-reference/{{page.version}}/#resourcefieldselector-v1-core) {% endcapture %}