website/content/zh/docs/concepts/configuration/overview.md

---
title: 配置最佳实践
content_type: concept
weight: 10
---
<!--
title: Configuration Best Practices
content_type: concept
weight: 10
-->

<!-- overview -->
<!--
This document highlights and consolidates configuration best practices that are introduced throughout the user guide, Getting Started documentation, and examples.
-->
本文档重点介绍并整合了整个用户指南、入门文档和示例中介绍的配置最佳实践。

<!--
This is a living document. If you think of something that is not on this list but might be useful to others, please don't hesitate to file an issue or submit a PR.
-->
这是一份不断改进的文件。
如果您认为某些内容缺失但可能对其他人有用，请不要犹豫，提交 Issue 或提交 PR。

<!-- body -->
<!--
## General Configuration Tips
-->
## 一般配置提示

<!--
- When defining configurations, specify the latest stable API version.
-->
- 定义配置时，请指定最新的稳定 API 版本。

<!--
- Configuration files should be stored in version control before being pushed to the cluster. This allows you to quickly roll back a configuration change if necessary. It also aids cluster re-creation and restoration.
-->
- 在推送到集群之前，配置文件应存储在版本控制中。
 这允许您在必要时快速回滚配置更改。
 它还有助于集群重新创建和恢复。 

<!--
- Write your configuration files using YAML rather than JSON. Though these formats can be used interchangeably in almost all scenarios, YAML tends to be more user-friendly.
-->
- 使用 YAML 而不是 JSON 编写配置文件。虽然这些格式几乎可以在所有场景中互换使用，但 YAML 往往更加用户友好。

<!--
- Group related objects into a single file whenever it makes sense. One file is often easier to manage than several. See the [guestbook-all-in-one.yaml](https://github.com/kubernetes/examples/tree/{{< param "githubbranch" >}}/guestbook/all-in-one/guestbook-all-in-one.yaml) file as an example of this syntax.
-->
- 只要有意义，就将相关对象分组到一个文件中。
 一个文件通常比几个文件更容易管理。
 请参阅[guestbook-all-in-one.yaml](https://github.com/kubernetes/examples/tree/{{< param "githubbranch" >}}/guestbook/all-in-one/guestbook-all-in-one.yaml) 文件作为此语法的示例。

<!--
- Note also that many `kubectl` commands can be called on a directory. For example, you can call `kubectl apply` on a directory of config files.
-->
- 另请注意，可以在目录上调用许多`kubectl`命令。
 例如，你可以在配置文件的目录中调用`kubectl apply`。

<!--
- Don't specify default values unnecessarily: simple, minimal configuration will make errors less likely.
-->
- 除非必要，否则不指定默认值：简单的最小配置会降低错误的可能性。

<!--
- Put object descriptions in annotations, to allow better introspection.
-->
- 将对象描述放在注释中，以便更好地进行内省。


<!--
## "Naked" Pods vs ReplicaSets, Deployments, and Jobs
-->
## “Naked”Pods 与 ReplicaSet，Deployment 和 Jobs

<!--
- Don't use naked Pods (that is, Pods not bound to a [ReplicaSet](/docs/concepts/workloads/controllers/replicaset/) or [Deployment](/docs/concepts/workloads/controllers/deployment/)) if you can avoid it. Naked Pods will not be rescheduled in the event of a node failure.
-->
- 如果可能，不要使用独立的 Pods（即，未绑定到
[ReplicaSet](/zh/docs/concepts/workloads/controllers/replicaset/) 或
[Deployment](/zh/docs/concepts/workloads/controllers/deployment/) 的 Pod）。
 如果节点发生故障，将不会重新调度独立的 Pods。

<!--
  A Deployment, which both creates a ReplicaSet to ensure that the desired number of Pods is always available, and specifies a strategy to replace Pods (such as [RollingUpdate](/docs/concepts/workloads/controllers/deployment/#rolling-update-deployment)), is almost always preferable to creating Pods directly, except for some explicit [`restartPolicy: Never`](/docs/concepts/workloads/pods/pod-lifecycle/#restart-policy) scenarios. A [Job](/docs/concepts/workloads/controllers/jobs-run-to-completion/) may also be appropriate.
-->

Deployment 既可以创建一个 ReplicaSet 来确保预期个数的 Pod 始终可用，也可以指定替换 Pod 的策略（例如
[RollingUpdate](/zh/docs/concepts/workloads/controllers/deployment/#rolling-update-deployment)）。
除了一些显式的 [`restartPolicy: Never`](/zh/docs/concepts/workloads/pods/pod-lifecycle/#restart-policy)
场景外，Deployment 通常比直接创建 Pod 要好得多。[Job](/zh/docs/concepts/workloads/controllers/job/) 也可能是合适的选择。

<!--
## Services
-->
## 服务

<!--
- Create a [Service](/docs/concepts/services-networking/service/) before its corresponding backend workloads (Deployments or ReplicaSets), and before any workloads that need to access it. When Kubernetes starts a container, it provides environment variables pointing to all the Services which were running when the container was started. For example, if a Service named `foo` exists, all containers will get the following variables in their initial environment:
-->
- 在创建相应的后端工作负载（Deployment 或 ReplicaSet），以及在需要访问它的任何工作负载之前创建
  [服务](/zh/docs/concepts/services-networking/service/)。
  当 Kubernetes 启动容器时，它提供指向启动容器时正在运行的所有服务的环境变量。
  例如，如果存在名为 `foo` 的服务，则所有容器将在其初始环境中获得以下变量。

  ```shell
  FOO_SERVICE_HOST=<the host the Service is running on>
  FOO_SERVICE_PORT=<the port the Service is running on>
  ```

<!--
  *This does imply an ordering requirement* - any `Service` that a `Pod` wants to access must be created before the `Pod` itself, or else the environment variables will not be populated.  DNS does not have this restriction.
-->
  *这确实意味着在顺序上的要求* - 必须在 `Pod` 本身被创建之前创建 `Pod` 想要访问的任何 `Service`，
  否则将环境变量不会生效。DNS 没有此限制。

<!--
- An optional (though strongly recommended) [cluster add-on](/docs/concepts/cluster-administration/addons/) is a DNS server.  The
DNS server watches the Kubernetes API for new `Services` and creates a set of DNS records for each.  If DNS has been enabled throughout the cluster then all `Pods` should be able to do name resolution of `Services` automatically.
-->
- 一个可选（尽管强烈推荐）的[集群插件](/zh/docs/concepts/cluster-administration/addons/)
  是 DNS 服务器。DNS 服务器为新的 `Services` 监视 Kubernetes API，并为每个创建一组 DNS 记录。
  如果在整个集群中启用了 DNS，则所有 `Pods` 应该能够自动对 `Services` 进行名称解析。

<!--
- Don't specify a `hostPort` for a Pod unless it is absolutely necessary. When you bind a Pod to a `hostPort`, it limits the number of places the Pod can be scheduled, because each <`hostIP`, `hostPort`, `protocol`> combination must be unique. If you don't specify the `hostIP` and `protocol` explicitly, Kubernetes will use `0.0.0.0` as the default `hostIP` and `TCP` as the default `protocol`.
-->
- 除非绝对必要，否则不要为 Pod 指定 `hostPort`。
  将 Pod 绑定到`hostPort`时，它会限制 Pod 可以调度的位置数，因为每个
  `<hostIP, hostPort, protocol>`组合必须是唯一的。
  如果您没有明确指定 `hostIP` 和 `protocol`，Kubernetes 将使用 `0.0.0.0` 作为默认
  `hostIP` 和 `TCP` 作为默认 `protocol`。

<!--
  If you only need access to the port for debugging purposes, you can use the [apiserver proxy](/docs/tasks/access-application-cluster/access-cluster/#manually-constructing-apiserver-proxy-urls) or [`kubectl port-forward`](/docs/tasks/access-application-cluster/port-forward-access-application-cluster/).
-->
  如果您只需要访问端口以进行调试，则可以使用
  [apiserver proxy](/zh/docs/tasks/access-application-cluster/access-cluster/#manually-constructing-apiserver-proxy-urls)或
  [`kubectl port-forward`](/zh/docs/tasks/access-application-cluster/port-forward-access-application-cluster/)。

<!--
  If you explicitly need to expose a Pod's port on the node, consider using a [NodePort](/docs/concepts/services-networking/service/#nodeport) Service before resorting to `hostPort`.
-->
  如果您明确需要在节点上公开 Pod 的端口，请在使用 `hostPort` 之前考虑使用
  [NodePort](/zh/docs/concepts/services-networking/service/#nodeport) 服务。

<!--
- Avoid using `hostNetwork`, for the same reasons as `hostPort`.
-->
- 避免使用 `hostNetwork`，原因与 `hostPort` 相同。

<!--
- Use [headless Services](/docs/concepts/services-networking/service/#headless-
services) (which have a `ClusterIP` of `None`) for service discovery when you don't need `kube-proxy` load balancing.
-->
- 当您不需要 `kube-proxy` 负载均衡时，使用
  [无头服务](/zh/docs/concepts/services-networking/service/#headless-services)  
  (`ClusterIP` 被设置为 `None`)以便于服务发现。

<!--
## Using Labels
-->
## 使用标签

<!--
- Define and use [labels](/docs/concepts/overview/working-with-objects/labels/) that identify __semantic attributes__ of your application or Deployment, such as `{ app: myapp, tier: frontend, phase: test, deployment: v3 }`. You can use these labels to select the appropriate Pods for other resources; for example, a Service that selects all `tier: frontend` Pods, or all `phase: test` components of `app: myapp`. See the [guestbook](https://github.com/kubernetes/examples/tree/{{< param "githubbranch" >}}/guestbook/) app for examples of this approach.
-->
- 定义并使用[标签](/zh/docs/concepts/overview/working-with-objects/labels/)来识别应用程序
  或 Deployment 的 __语义属性__，例如`{ app: myapp, tier: frontend, phase: test, deployment: v3 }`。
  你可以使用这些标签为其他资源选择合适的 Pod；
  例如，一个选择所有 `tier: frontend` Pod 的服务，或者 `app: myapp` 的所有 `phase: test` 组件。
  有关此方法的示例，请参阅[guestbook](https://github.com/kubernetes/examples/tree/{{< param "githubbranch" >}}/guestbook/) 。

<!--
A Service can be made to span multiple Deployments by omitting release-specific labels from its selector. [Deployments](/docs/concepts/workloads/controllers/deployment/) make it easy to update a running service without downtime.
-->
通过从选择器中省略特定发行版的标签，可以使服务跨越多个 Deployment。
当你需要不停机的情况下更新正在运行的服务，可以使用[Deployment](/zh/docs/concepts/workloads/controllers/deployment/)。

<!--
A desired state of an object is described by a Deployment, and if changes to that spec are _applied_, the deployment controller changes the actual state to the desired state at a controlled rate.
-->
Deployment 描述了对象的期望状态，并且如果对该规范的更改被成功应用，
则 Deployment 控制器以受控速率将实际状态改变为期望状态。

<!--
- Use the [Kubernetes common labels](/docs/concepts/overview/working-with-objects/common-labels/) for common use cases. These standardized labels enrich the metadata in a way that allows tools, including `kubectl` and [dashboard](/docs/tasks/access-application-cluster/web-ui-dashboard), to work in an interoperable way.
-->

- 对于常见场景，应使用 [Kubernetes 通用标签](/zh/docs/concepts/overview/working-with-objects/common-labels/)。
  这些标准化的标签丰富了对象的元数据，使得包括 `kubectl` 和
  [仪表板（Dashboard）](/zh/docs/tasks/access-application-cluster/web-ui-dashboard)
  这些工具能够以可互操作的方式工作。

<!--
- You can manipulate labels for debugging. Because Kubernetes controllers (such as ReplicaSet) and Services match to Pods using selector labels, removing the relevant labels from a Pod will stop it from being considered by a controller or from being served traffic by a Service. If you remove the labels of an existing Pod, its controller will create a new Pod to take its place. This is a useful way to debug a previously "live" Pod in a "quarantine" environment. To interactively remove or add labels, use [`kubectl label`](/docs/reference/generated/kubectl/kubectl-commands#label).
-->
- 您可以操纵标签进行调试。
  由于 Kubernetes 控制器（例如 ReplicaSet）和服务使用选择器标签来匹配 Pod，
  从 Pod 中删除相关标签将阻止其被控制器考虑或由服务提供服务流量。
  如果删除现有 Pod 的标签，其控制器将创建一个新的 Pod 来取代它。
  这是在"隔离"环境中调试先前"活跃"的 Pod 的有用方法。
  要以交互方式删除或添加标签，请使用 [`kubectl label`](/docs/reference/generated/kubectl/kubectl-commands#label)。

<!--
## Container Images
-->
## 容器镜像

<!--
The [imagePullPolicy](/docs/concepts/containers/images/#updating-images) and the tag of the image affect when the [kubelet](/docs/reference/command-line-tools-reference/kubelet/) attempts to pull the specified image.
-->
[imagePullPolicy](/zh/docs/concepts/containers/images/#updating-images)和镜像标签会影响
[kubelet](/zh/docs/reference/command-line-tools-reference/kubelet/) 何时尝试拉取指定的镜像。

<!--
- `imagePullPolicy: IfNotPresent`: the image is pulled only if it is not already present locally.
- `imagePullPolicy: Always`: the image is pulled every time the pod is started.
- `imagePullPolicy` is omitted and either the image tag is `:latest` or it is omitted: `imagePullPolicy` is automatically set to `Always`. Note that this will _not_ be updated to `IfNotPresent` if the tag changes value.
- `imagePullPolicy` is omitted and the image tag is present but not `:latest`: `imagePullPolicy` is automatically set to `IfNotPresent`. Note that this will _not_ be updated to `Always` if the tag is later removed or changed to `:latest`.
- `imagePullPolicy: Never`: the image is assumed to exist locally. No attempt is made to pull the image.
-->
- `imagePullPolicy: IfNotPresent`：仅当镜像在本地不存在时才被拉取。
- `imagePullPolicy: Always`：每次启动 Pod 的时候都会拉取镜像。
- `imagePullPolicy` 省略时，镜像标签为 `:latest` 或不存在，其值自动被设置为 `Always`。注意，如果镜像标签的值发生改变，`imagePullPolicy` 的值不会被更新为 `IfNotPresent`。
- `imagePullPolicy` 省略时，指定镜像标签并且不是 `:latest`，其值自动被设置为 `IfNotPresent`。注意，如果镜像标签的值之后被移除或者修改为 `latest`，`imagePullPolicy` 的值不会被更新为 `Always`。
- `imagePullPolicy: Never`：假设镜像已经存在本地，不会尝试拉取镜像。

<!--
To make sure the container always uses the same version of the image, you can specify its [digest](https://docs.docker.com/engine/reference/commandline/pull/#pull-an-image-by-digest-immutable-identifier), for example `sha256:45b23dee08af5e43a7fea6c4cf9c25ccf269ee113168c19722f87876677c5cb2`. The digest uniquely identifies a specific version of the image, so it is never updated by Kubernetes unless you change the digest value.
-->
{{< note >}}
要确保容器始终使用相同版本的镜像，你可以指定其
[摘要](https://docs.docker.com/engine/reference/commandline/pull/#pull-an-image-by-digest-immutable-identifier)，
例如 `sha256:45b23dee08af5e43a7fea6c4cf9c25ccf269ee113168c19722f87876677c5cb2`。
摘要唯一地标识出镜像的指定版本，因此除非您更改摘要值，否则 Kubernetes 永远不会更新它。
{{< /note >}}

<!--
You should avoid using the `:latest` tag when deploying containers in production as it is harder to track which version of the image is running and more difficult to roll back properly.
-->
{{< note >}}
在生产中部署容器时应避免使用 `:latest` 标记，因为这样更难跟踪正在运行的镜像版本，并且更难以正确回滚。 
{{< /note >}}

<!--
The caching semantics of the underlying image provider make even `imagePullPolicy: Always` efficient, as long as the registry is reliably accessible. With Docker, for example, if the image already exists, the pull attempt is fast because all image layers are cached and no image download is needed.
-->
{{< note >}}
只要镜像仓库是可访问的，底层镜像驱动程序的缓存语义能够使即便 `imagePullPolicy: Always` 的配置也很高效。
例如，对于 Docker，如果镜像已经存在，则拉取尝试很快，因为镜像层都被缓存并且不需要下载。
{{< /note >}}

<!--
## Using kubectl
-->
## 使用 kubectl

<!--
- Use `kubectl apply -f <directory>`. This looks for Kubernetes configuration in all `.yaml`, `.yml`, and `.json` files in `<directory>` and passes it to `apply`.
-->
- 使用 `kubectl apply -f <directory>`。
  它在 `<directory>` 中的所有` .yaml`、`.yml` 和 `.json` 文件中查找 Kubernetes 配置，并将其传递给 `apply`。

<!--
- Use label selectors for `get` and `delete` operations instead of specific object names. See the sections on [label selectors](/docs/concepts/overview/working-with-objects/labels/#label-selectors) and [using labels effectively](/docs/concepts/cluster-administration/manage-deployment/#using-labels-effectively).
-->
- 使用标签选择器进行 `get` 和 `delete` 操作，而不是特定的对象名称。
- 请参阅[标签选择器](/zh/docs/concepts/overview/working-with-objects/labels/#label-selectors)和
  [有效使用标签](/zh/docs/concepts/cluster-administration/manage-deployment/#using-labels-effectively)部分。

<!--
- Use `kubectl run` and `kubectl expose` to quickly create single-container Deployments and Services. See [Use a Service to Access an Application in a Cluster](/docs/tasks/access-application-cluster/service-access-application-cluster/) for an example.
-->
- 使用`kubectl run`和`kubectl expose`来快速创建单容器部署和服务。
  有关示例，请参阅[使用服务访问集群中的应用程序](/zh/docs/tasks/access-application-cluster/service-access-application-cluster/)。