---
title: 容器运行时接口（CRI）
content_type: concept
weight: 60
---

<!-- 
title: Container Runtime Interface (CRI)
content_type: concept
weight: 60
-->

<!-- overview -->
<!-- 
The CRI is a plugin interface which enables the kubelet to use a wide variety of
container runtimes, without having a need to recompile the cluster components.

You need a working
{{<glossary_tooltip text="container runtime" term_id="container-runtime">}} on
each Node in your cluster, so that the
{{< glossary_tooltip text="kubelet" term_id="kubelet" >}} can launch
{{< glossary_tooltip text="Pods" term_id="pod" >}} and their containers.
-->
CRI 是一个插件接口，它使 kubelet 能够使用各种容器运行时，无需重新编译集群组件。

你需要在集群中的每个节点上都有一个可以正常工作的{{<glossary_tooltip text="容器运行时" term_id="container-runtime">}}，
这样 {{< glossary_tooltip text="kubelet" term_id="kubelet" >}} 能启动
{{< glossary_tooltip text="Pod" term_id="pod" >}} 及其容器。

{{< glossary_definition prepend="容器运行时接口（CRI）是" term_id="cri" length="all" >}}

<!-- body -->
<!--
## The API {#api}
-->
## API {#api}

{{< feature-state for_k8s_version="v1.23" state="stable" >}}

<!--
The kubelet acts as a client when connecting to the container runtime via gRPC.
The runtime and image service endpoints have to be available in the container
runtime, which can be configured separately within the kubelet by using the
`--image-service-endpoint` [command line flags](/docs/reference/command-line-tools-reference/kubelet).
-->
当通过 gRPC 连接到容器运行时，kubelet 将充当客户端。运行时和镜像服务端点必须在容器运行时中可用，
可以使用 `--image-service-endpoint`
[命令行标志](/zh-cn/docs/reference/command-line-tools-reference/kubelet)在 kubelet 中单独配置。

<!-- 
For Kubernetes v{{< skew currentVersion >}}, the kubelet prefers to use CRI `v1`.
If a container runtime does not support `v1` of the CRI, then the kubelet tries to
negotiate any older supported version.
The v{{< skew currentVersion >}} kubelet can also negotiate CRI `v1alpha2`, but
this version is considered as deprecated.
If the kubelet cannot negotiate a supported CRI version, the kubelet gives up
and doesn't register as a node.
-->
对 Kubernetes v{{< skew currentVersion >}}，kubelet 偏向于使用 CRI `v1` 版本。
如果容器运行时不支持 CRI 的 `v1` 版本，那么 kubelet 会尝试协商较老的、仍被支持的所有版本。
v{{< skew currentVersion >}} 版本的 kubelet 也可协商 CRI `v1alpha2` 版本，但该版本被视为已弃用。
如果 kubelet 无法协商出可支持的 CRI 版本，则 kubelet 放弃并且不会注册为节点。

<!-- 
## Upgrading

When upgrading Kubernetes, the kubelet tries to automatically select the
latest CRI version on restart of the component. If that fails, then the fallback
will take place as mentioned above. If a gRPC re-dial was required because the
container runtime has been upgraded, then the container runtime must also
support the initially selected version or the redial is expected to fail. This
requires a restart of the kubelet.
-->
## 升级  {#upgrading}

升级 Kubernetes 时，kubelet 会尝试在组件重启时自动选择最新的 CRI 版本。
如果失败，则将如上所述进行回退。如果由于容器运行时已升级而需要 gRPC 重拨，
则容器运行时还必须支持最初选择的版本，否则重拨预计会失败。
这需要重新启动 kubelet。

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

<!-- 
- Learn more about the CRI [protocol definition](https://github.com/kubernetes/cri-api/blob/c75ef5b/pkg/apis/runtime/v1/api.proto)
-->
- 了解更多有关 CRI [协议定义](https://github.com/kubernetes/cri-api/blob/c75ef5b/pkg/apis/runtime/v1/api.proto)