---
title: 使用 Node 鉴权
content_type: concept
weight: 90
---
<!--
---
reviewers:
- timstclair
- deads2k
- liggitt
- ericchiang
title: Using Node Authorization
content_type: concept
weight: 90
---
-->

<!-- overview -->
节点鉴权是一种特殊用途的鉴权模式，专门对 kubelet 发出的 API 请求进行鉴权。
<!--
Node authorization is a special-purpose authorization mode that specifically authorizes API requests made by kubelets.
-->


<!-- body -->
## 概述
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## Overview
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节点鉴权器允许 kubelet 执行 API 操作。包括：
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The Node authorizer allows a kubelet to perform API operations. This includes:
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读取操作：
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Read operations:
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* services
* endpoints
* nodes
* pods
* secrets、configmaps、pvcs 以及绑定到 kubelet 节点的与 pod 相关的持久卷

<!--
* services
* endpoints
* nodes
* pods
* secrets, configmaps, persistent volume claims and persistent volumes related to pods bound to the kubelet's node
-->

写入操作：
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Write operations:
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* 节点和节点状态（启用 `NodeRestriction` 准入插件以限制 kubelet 只能修改自己的节点）
* Pod 和 Pod 状态 (启用 `NodeRestriction` 准入插件以限制 kubelet 只能修改绑定到自身的 Pod)
* 事件

<!--
* nodes and node status (enable the `NodeRestriction` admission plugin to limit a kubelet to modify its own node)
* pods and pod status (enable the `NodeRestriction` admission plugin to limit a kubelet to modify pods bound to itself)
* events
-->

鉴权相关操作：
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Auth-related operations:
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* 对于基于 TLS 的启动引导过程时使用的 certificationsigningrequests API 的读/写权限
* 为委派的身份验证/授权检查创建 tokenreviews 和 subjectaccessreviews 的能力

<!--
* read/write access to the certificationsigningrequests API for TLS bootstrapping
* the ability to create tokenreviews and subjectaccessreviews for delegated authentication/authorization checks
-->

在将来的版本中，节点鉴权器可能会添加或删除权限，以确保 kubelet 具有正确操作所需的最小权限集。
<!--
In future releases, the node authorizer may add or remove permissions to ensure kubelets
have the minimal set of permissions required to operate correctly.
-->

为了获得节点鉴权器的授权，kubelet 必须使用一个凭证以表示它在 `system:nodes` 组中，用户名为 `system:node:<nodeName>`。
上述的组名和用户名格式要与 [kubelet TLS 启动引导](/zh/docs/reference/command-line-tools-reference/kubelet-tls-bootstrapping/)过程中为每个 kubelet 创建的标识相匹配。
<!--
In order to be authorized by the Node authorizer, kubelets must use a credential that identifies them as
being in the `system:nodes` group, with a username of `system:node:<nodeName>`.
This group and user name format match the identity created for each kubelet as part of
[kubelet TLS bootstrapping](/docs/reference/command-line-tools-reference/kubelet-tls-bootstrapping/).
-->

要启用节点授权器，请使用 `--authorization-mode = Node` 启动 apiserver。
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To enable the Node authorizer, start the apiserver with `--authorization-mode=Node`.
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要限制 kubelet 具有写入权限的 API 对象，请使用 `--enable-admission-plugins=...,NodeRestriction,...` 启动 apiserver，从而启用 [NodeRestriction](/zh/docs/reference/access-authn-authz/admission-controllers#NodeRestriction) 准入插件。
<!--
To limit the API objects kubelets are able to write, enable the [NodeRestriction](/docs/reference/access-authn-authz/admission-controllers#NodeRestriction) admission plugin by starting the apiserver with `--enable-admission-plugins=...,NodeRestriction,...`
 -->

## 迁移考虑因素
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## Migration considerations
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### 在 `system:nodes` 组之外的 Kubelet
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### Kubelets outside the `system:nodes` group
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`system:nodes` 组之外的 kubelet 不会被 `Node` 鉴权模式授权，并且需要继续通过当前授权它们的机制来授权。
节点准入插件不会限制来自这些 kubelet 的请求。
<!--
Kubelets outside the `system:nodes` group would not be authorized by the `Node` authorization mode,
and would need to continue to be authorized via whatever mechanism currently authorizes them.
The node admission plugin would not restrict requests from these kubelets.
-->

### 具有无差别用户名的 Kubelet
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### Kubelets with undifferentiated usernames
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在一些部署中，kubelet 具有 `system:nodes` 组的凭证，但是无法给出它们所关联的节点的标识，因为它们没有 `system:node:...` 格式的用户名。
这些 kubelet 不会被 `Node` 授权模式授权，并且需要继续通过当前授权它们的任何机制来授权。
<!--
In some deployments, kubelets have credentials that place them in the `system:nodes` group,
but do not identify the particular node they are associated with,
because they do not have a username in the `system:node:...` format.
These kubelets would not be authorized by the `Node` authorization mode,
and would need to continue to be authorized via whatever mechanism currently authorizes them.
-->

因为默认的节点标识符实现不会把它当作节点身份标识，`NodeRestriction` 准入插件会忽略来自这些 kubelet 的请求。
<!--
The `NodeRestriction` admission plugin would ignore requests from these kubelets,
since the default node identifier implementation would not consider that a node identity.
-->

### 相对于以前使用 RBAC 的版本的更新
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### Upgrades from previous versions using RBAC
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升级的 1.7 之前的使用 [RBAC](/zh/docs/reference/access-authn-authz/rbac/) 的集群将继续按原样运行，因为 `system:nodes` 组绑定已经存在。
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Upgraded pre-1.7 clusters using [RBAC](/docs/reference/access-authn-authz/rbac/) will continue functioning as-is because the `system:nodes` group binding will already exist.
-->

如果集群管理员希望开始使用 `Node` 鉴权器和 `NodeRestriction` 准入插件来限制节点对 API 的访问，这一需求可以通过下列操作来完成且不会影响已部署的应用：
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If a cluster admin wishes to start using the `Node` authorizer and `NodeRestriction` admission plugin
to limit node access to the API, that can be done non-disruptively:
 -->

1. 启用 `Node` 鉴权模式 (`--authorization-mode=Node,RBAC`) 和 `NodeRestriction` 准入插件
2. 确保所有 kubelet 的凭据符合组/用户名要求
3. 审核 apiserver 日志以确保 `Node` 鉴权器不会拒绝来自 kubelet 的请求（日志中没有持续的 `NODE DENY` 消息）
4. 删除 `system:node` 集群角色绑定
<!--
1. Enable the `Node` authorization mode (`--authorization-mode=Node,RBAC`) and the `NodeRestriction` admission plugin
2. Ensure all kubelets' credentials conform to the group/username requirements
3. Audit apiserver logs to ensure the `Node` authorizer is not rejecting requests from kubelets (no persistent `NODE DENY` messages logged)
4. Delete the `system:node` cluster role binding
-->

### RBAC 节点权限
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### RBAC Node Permissions
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在 1.6 版本中，当使用 [RBAC 鉴权模式](/zh/docs/reference/access-authn-authz/rbac/) 时，`system:nodes` 集群角色会被自动绑定到 `system:node` 组。
<!--
In 1.6, the `system:node` cluster role was automatically bound to the `system:nodes` group when using the [RBAC Authorization mode](/docs/reference/access-authn-authz/rbac/).
-->

在 1.7 版本中，不再推荐将 `system:nodes` 组自动绑定到 `system:node` 角色，因为节点鉴权器通过对 secret 和 configmap 访问的额外限制完成了相同的任务。
如果同时启用了 `Node` 和 `RBAC` 授权模式，1.7 版本则不会创建 `system:nodes` 组到 `system:node` 角色的自动绑定。
<!--
In 1.7, the automatic binding of the `system:nodes` group to the `system:node` role is deprecated
because the node authorizer accomplishes the same purpose with the benefit of additional restrictions
on secret and configmap access. If the `Node` and `RBAC` authorization modes are both enabled,
the automatic binding of the `system:nodes` group to the `system:node` role is not created in 1.7.
-->

在 1.8 版本中，绑定将根本不会被创建。
<!--
In 1.8, the binding will not be created at all.
-->

使用 RBAC 时，将继续创建 `system:node` 集群角色，以便与将其他用户或组绑定到该角色的部署方法兼容。
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When using RBAC, the `system:node` cluster role will continue to be created,
for compatibility with deployment methods that bind other users or groups to that role.
-->
