---
title: 管理集群中的 TLS 认证
content_type: task
---
<!--
title: Manage TLS Certificates in a Cluster
content_type: task
reviewers:
- mikedanese
- beacham
- liggit
-->

<!-- overview -->
<!--
Kubernetes provides a `certificates.k8s.io` API, which lets you provision TLS
certificates signed by a Certificate Authority (CA) that you control. These CA
and certificates can be used by your workloads to establish trust.

`certificates.k8s.io` API uses a protocol that is similar to the [ACME
draft](https://github.com/ietf-wg-acme/acme/).
-->
Kubernetes 提供 `certificates.k8s.io` API，可让你配置由你控制的证书颁发机构（CA）
签名的 TLS 证书。 你的工作负载可以使用这些 CA 和证书来建立信任。

`certificates.k8s.io` API使用的协议类似于
[ACME 草案](https://github.com/ietf-wg-acme/acme/)。

{{< note >}}
<!--
Certificates created using the `certificates.k8s.io` API are signed by a
[dedicated CA](#configuring-your-cluster-to-provide-signing). It is possible to configure your cluster to use the cluster root
CA for this purpose, but you should never rely on this. Do not assume that
these certificates will validate against the cluster root CA.
-->
使用 `certificates.k8s.io` API 创建的证书由指定 [CA](#configuring-your-cluster-to-provide-signing) 颁发。
将集群配置为使用集群根目录 CA 可以达到这个目的，但是你永远不要依赖这一假定。
不要以为这些证书将针对群根目录 CA 进行验证。
{{< /note >}}

## {{% heading "prerequisites" %}}

{{< include "task-tutorial-prereqs.md" >}}

<!-- 
You need the `cfssl` tool. You can download `cfssl` from
[https://github.com/cloudflare/cfssl/releases](https://github.com/cloudflare/cfssl/releases).

Some steps in this page use the `jq` tool. If you don't have `jq`, you can
install it via your operating system's software sources, or fetch it from
[https://jqlang.github.io/jq/](https://jqlang.github.io/jq/).
-->
你需要 `cfssl` 工具。
你可以从 [https://github.com/cloudflare/cfssl/releases](https://github.com/cloudflare/cfssl/releases)
下载 `cfssl`。

本文中某些步骤使用 `jq` 工具。如果你没有 `jq`，你可以通过操作系统的软件源安装，
或者从 [https://jqlang.github.io/jq/](https://jqlang.github.io/jq/) 获取。

<!-- steps -->

<!--
## Trusting TLS in a cluster

Trusting the [custom CA](#configuring-your-cluster-to-provide-signing) from an application running as a pod usually requires
some extra application configuration. You will need to add the CA certificate
bundle to the list of CA certificates that the TLS client or server trusts. For
example, you would do this with a golang TLS config by parsing the certificate
chain and adding the parsed certificates to the `RootCAs` field in the
[`tls.Config`](https://pkg.go.dev/crypto/tls#Config) struct.
-->
## 集群中的 TLS 信任

信任 Pod 中运行的应用程序所提供的[自定义 CA](#configuring-your-cluster-to-provide-signing) 通常需要一些额外的应用程序配置。
你需要将 CA 证书包添加到 TLS 客户端或服务器信任的 CA 证书列表中。
例如，你可以使用 Golang TLS 配置通过解析证书链并将解析的证书添加到
[`tls.Config`](https://pkg.go.dev/crypto/tls#Config) 结构中的 `RootCAs`
字段中。

{{< note >}}
<!-- 
Even though the custom CA certificate may be included in the filesystem (in the
ConfigMap `kube-root-ca.crt`),
you should not use that certificate authority for any purpose other than to verify internal
Kubernetes endpoints. An example of an internal Kubernetes endpoint is the
Service named `kubernetes` in the default namespace.

If you want to use a custom certificate authority for your workloads, you should generate
that CA separately, and distribute its CA certificate using a 
[ConfigMap](/docs/tasks/configure-pod-container/configure-pod-configmap) that your pods 
have access to read.
-->
即使自定义 CA 证书可能包含在文件系统中（在 ConfigMap `kube-root-ca.crt` 中），
除了验证内部 Kubernetes 端点之外，你不应将该证书颁发机构用于任何目的。
内部 Kubernetes 端点的一个示例是默认命名空间中名为 `kubernetes` 的服务。

如果你想为你的工作负载使用自定义证书颁发机构，你应该单独生成该 CA，
并使用你的 Pod 有读权限的 [ConfigMap](/zh-cn/docs/tasks/configure-pod-container/configure-pod-configmap)
分发该 CA 证书。
{{< /note >}}

<!--
## Requesting a certificate

The following section demonstrates how to create a TLS certificate for a
Kubernetes service accessed through DNS.

{{< note >}}
This tutorial uses CFSSL: Cloudflare's PKI and TLS toolkit [click here](https://blog.cloudflare.com/introducing-cfssl/) to know more.
{{< /note >}}
-->
## 请求证书

以下部分演示如何为通过 DNS 访问的 Kubernetes 服务创建 TLS 证书。

{{< note >}}
本教程使用 CFSSL：Cloudflare's PKI 和 TLS 工具包
[点击此处](https://blog.cloudflare.com/introducing-cfssl/)了解更多信息。
{{< /note >}}

<!--
## Create a certificate signing request

Generate a private key and certificate signing request (or CSR) by running
the following command:
-->
## 创建证书签名请求

通过运行以下命令生成私钥和证书签名请求（或 CSR）:

```shell
cat <<EOF | cfssl genkey - | cfssljson -bare server
{
  "hosts": [
    "my-svc.my-namespace.svc.cluster.local",
    "my-pod.my-namespace.pod.cluster.local",
    "192.0.2.24",
    "10.0.34.2"
  ],
  "CN": "my-pod.my-namespace.pod.cluster.local",
  "key": {
    "algo": "ecdsa",
    "size": 256
  }
}
EOF
```

<!--
Where `192.0.2.24` is the service's cluster IP,
`my-svc.my-namespace.svc.cluster.local` is the service's DNS name,
`10.0.34.2` is the pod's IP and `my-pod.my-namespace.pod.cluster.local`
is the pod's DNS name. You should see the output similar to:
-->
其中 `192.0.2.24` 是服务的集群 IP，`my-svc.my-namespace.svc.cluster.local`
是服务的 DNS 名称，`10.0.34.2` 是 Pod 的 IP，而
`my-pod.my-namespace.pod.cluster.local` 是 Pod 的 DNS 名称。
你能看到的输出类似于：

```
2022/02/01 11:45:32 [INFO] generate received request
2022/02/01 11:45:32 [INFO] received CSR
2022/02/01 11:45:32 [INFO] generating key: ecdsa-256
2022/02/01 11:45:32 [INFO] encoded CSR
```

<!--
This command generates two files; it generates `server.csr` containing the PEM
encoded [PKCS#10](https://tools.ietf.org/html/rfc2986) certification request,
and `server-key.pem` containing the PEM encoded key to the certificate that
is still to be created.
-->
此命令生成两个文件；它生成包含 PEM 编码
[PKCS#10](https://tools.ietf.org/html/rfc2986) 证书请求的 `server.csr`，
以及 PEM 编码密钥的 `server-key.pem`，用于待生成的证书。

<!--
## Create a CertificateSigningRequest object to send to the Kubernetes API

Generate a CSR manifest (in YAML), and send it to the API server. You can do that by
running the following command:
-->
## 创建证书签名请求（CSR）对象发送到 Kubernetes API

你可以使用以下命令创建 CSR 清单（YAML 格式），并发送到 API 服务器：

```shell
cat <<EOF | kubectl apply -f -
apiVersion: certificates.k8s.io/v1
kind: CertificateSigningRequest
metadata:
  name: my-svc.my-namespace
spec:
  request: $(cat server.csr | base64 | tr -d '\n')
  signerName: example.com/serving
  usages:
  - digital signature
  - key encipherment
  - server auth
EOF
```

<!--
Notice that the `server.csr` file created in step 1 is base64 encoded
and stashed in the `.spec.request` field. You are also requesting a
certificate with the "digital signature", "key encipherment", and "server
auth" key usages, signed by an example `example.com/serving` signer.
A specific `signerName` must be requested.
View documentation for [supported signer names](/docs/reference/access-authn-authz/certificate-signing-requests/#signers)
for more information.

The CSR should now be visible from the API in a Pending state. You can see
it by running:
-->
请注意，在步骤 1 中创建的 `server.csr` 文件是 base64 编码并存储在
`.spec.request` 字段中的。你还要求提供 “digital signature（数字签名）”，
“密钥加密（key encipherment）” 和 “服务器身份验证（server auth）” 密钥用途，
由 `example.com/serving` 示例签名程序签名的证书。
你也可以要求使用特定的 `signerName`。更多信息可参阅
[支持的签署者名称](/zh-cn/docs/reference/access-authn-authz/certificate-signing-requests/#signers)。

在 API server 中可以看到这些 CSR 处于 Pending 状态。执行下面的命令你将可以看到：

```shell
kubectl describe csr my-svc.my-namespace
```

```none
Name:                   my-svc.my-namespace
Labels:                 <none>
Annotations:            <none>
CreationTimestamp:      Tue, 01 Feb 2022 11:49:15 -0500
Requesting User:        yourname@example.com
Signer:                 example.com/serving
Status:                 Pending
Subject:
        Common Name:    my-pod.my-namespace.pod.cluster.local
        Serial Number:
Subject Alternative Names:
        DNS Names:      my-pod.my-namespace.pod.cluster.local
                        my-svc.my-namespace.svc.cluster.local
        IP Addresses:   192.0.2.24
                        10.0.34.2
Events: <none>
```

<!--
## Get the CertificateSigningRequest approved {#get-the-certificate-signing-request-approved}

Approving the [certificate signing request](/docs/reference/access-authn-authz/certificate-signing-requests/)
is either done by an automated approval process or on a one off basis by a cluster
administrator. If you're authorized to approve a certificate request, you can do that
manually using `kubectl`; for example:
-->
## 批准证书签名请求（CSR）  {#get-the-certificate-signing-request-approved}

[证书签名请求](/zh-cn/docs/reference/access-authn-authz/certificate-signing-requests/)
的批准或者是通过自动批准过程完成的，或由集群管理员一次性完成。
如果你被授权批准证书请求，你可以使用 `kubectl` 来手动完成此操作；例如：

```shell
kubectl certificate approve my-svc.my-namespace
```

```none
certificatesigningrequest.certificates.k8s.io/my-svc.my-namespace approved
```

<!-- You should now see the following: -->
你现在应该能看到如下输出：

```shell
kubectl get csr
```

```none
NAME                  AGE   SIGNERNAME            REQUESTOR              REQUESTEDDURATION   CONDITION
my-svc.my-namespace   10m   example.com/serving   yourname@example.com   <none>              Approved
```

<!-- 
This means the certificate request has been approved and is waiting for the
requested signer to sign it.
-->
这意味着证书请求已被批准，并正在等待请求的签名者对其签名。

<!--  
## Sign the CertificateSigningRequest {#sign-the-certificate-signing-request}

Next, you'll play the part of a certificate signer, issue the certificate, and upload it to the API.

A signer would typically watch the CertificateSigningRequest API for objects with its `signerName`,
check that they have been approved, sign certificates for those requests,
and update the API object status with the issued certificate.
-->
## 签名证书签名请求（CSR） {#sign-the-certificate-signing-request}

接下来，你将扮演证书签署者的角色，颁发证书并将其上传到 API 服务器。

签名者通常会使用其 `signerName` 查看对象的 CertificateSigningRequest API，
检查它们是否已被批准，为这些请求签署证书，并使用已颁发的证书更新 API 对象状态。

<!-- 
### Create a Certificate Authority

You need an authority to provide the digital signature on the new certificate.

First, create a signing certificate by running the following:
-->
### 创建证书颁发机构

你需要授权在新证书上提供数字签名。

首先，通过运行以下命令创建签名证书：

```shell
cat <<EOF | cfssl gencert -initca - | cfssljson -bare ca
{
  "CN": "My Example Signer",
  "key": {
    "algo": "rsa",
    "size": 2048
  }
}
EOF
```

<!-- You should see output similar to: -->
你应该看到类似于以下的输出：

```none
2022/02/01 11:50:39 [INFO] generating a new CA key and certificate from CSR
2022/02/01 11:50:39 [INFO] generate received request
2022/02/01 11:50:39 [INFO] received CSR
2022/02/01 11:50:39 [INFO] generating key: rsa-2048
2022/02/01 11:50:39 [INFO] encoded CSR
2022/02/01 11:50:39 [INFO] signed certificate with serial number 263983151013686720899716354349605500797834580472
```

<!-- 
This produces a certificate authority key file (`ca-key.pem`) and certificate (`ca.pem`).
-->
这会产生一个证书颁发机构密钥文件（`ca-key.pem`）和证书（`ca.pem`）。


<!-- ### Issue a certificate -->
### 颁发证书

{{% code_sample file="tls/server-signing-config.json" %}}

<!-- 
Use a `server-signing-config.json` signing configuration and the certificate authority key file 
and certificate to sign the certificate request:
-->
使用 `server-signing-config.json` 签名配置、证书颁发机构密钥文件和证书来签署证书请求：

```shell
kubectl get csr my-svc.my-namespace -o jsonpath='{.spec.request}' | \
  base64 --decode | \
  cfssl sign -ca ca.pem -ca-key ca-key.pem -config server-signing-config.json - | \
  cfssljson -bare ca-signed-server
```

<!--
You should see the output similar to:
-->
你应该看到类似于以下的输出：

```
2022/02/01 11:52:26 [INFO] signed certificate with serial number 576048928624926584381415936700914530534472870337
```

<!--
This produces a signed serving certificate file, `ca-signed-server.pem`.
-->
这会生成一个签名的服务证书文件，`ca-signed-server.pem`。

<!-- 
### Upload the signed certificate

Finally, populate the signed certificate in the API object's status:
-->

### 上传签名证书

最后，在 API 对象的状态中填充签名证书：

```shell
kubectl get csr my-svc.my-namespace -o json | \
  jq '.status.certificate = "'$(base64 ca-signed-server.pem | tr -d '\n')'"' | \
  kubectl replace --raw /apis/certificates.k8s.io/v1/certificatesigningrequests/my-svc.my-namespace/status -f -
```

{{< note >}}
<!-- 
This uses the command line tool [`jq`](https://jqlang.github.io/jq/) to populate the base64-encoded
content in the `.status.certificate` field.
If you do not have `jq`, you can also save the JSON output to a file, populate this field manually, and
upload the resulting file.
-->
这使用命令行工具 [`jq`](https://jqlang.github.io/jq/)
在 `.status.certificate` 字段中填充 base64 编码的内容。
如果你没有 `jq` 工具，你还可以将 JSON 输出保存到文件中，手动填充此字段，然后上传结果文件。
{{< /note >}}

<!-- 
Once the CSR is approved and the signed certificate is uploaded, run:
-->
批准 CSR 并上传签名证书后，运行：

```shell
kubectl get csr
```

<!-- The output is similar to: -->
输入类似于：

```none
NAME                  AGE   SIGNERNAME            REQUESTOR              REQUESTEDDURATION   CONDITION
my-svc.my-namespace   20m   example.com/serving   yourname@example.com   <none>              Approved,Issued
```

<!--
## Download the certificate and use it

Now, as the requesting user, you can download the issued certificate
and save it to a `server.crt` file by running the following:
-->
## 下载证书并使用它

现在，作为请求用户，你可以通过运行以下命令下载颁发的证书并将其保存到 `server.crt` 文件中：

CSR 被签署并获得批准后，你应该看到以下内容：

```shell
kubectl get csr my-svc.my-namespace -o jsonpath='{.status.certificate}' \
    | base64 --decode > server.crt
```

<!--
Now you can populate `server.crt` and `server-key.pem` in a
{{< glossary_tooltip text="Secret" term_id="secret" >}}
that you could later mount into a Pod (for example, to use with a webserver
that serves HTTPS).
-->
现在你可以将 `server.crt` 和 `server-key.pem` 填充到
{{<glossary_tooltip text="Secret" term_id="secret" >}} 中，
稍后你可以将其挂载到 Pod 中（例如，用于提供 HTTPS 的网络服务器）。

```shell
kubectl create secret tls server --cert server.crt --key server-key.pem
```

```none
secret/server created
```

<!-- 
Finally, you can populate `ca.pem` into a {{< glossary_tooltip text="ConfigMap" term_id="configmap" >}}
and use it as the trust root to verify the serving certificate:
-->
最后，你可以将 `ca.pem` 填充到
{{<glossary_tooltip text="ConfigMap" term_id="configmap" >}}
并将其用作信任根来验证服务证书：

```shell
kubectl create configmap example-serving-ca --from-file ca.crt=ca.pem
```

```none
configmap/example-serving-ca created
```

<!--
## Approving CertificateSigningRequests {#approving-certificate-signing-requests}

A Kubernetes administrator (with appropriate permissions) can manually approve
(or deny) CertificateSigningRequests by using the `kubectl certificate
approve` and `kubectl certificate deny` commands. However if you intend
to make heavy usage of this API, you might consider writing an automated
certificates controller.
-->
## 批准证书签名请求（CSR）  {#approving-certificate-signing-requests}

Kubernetes 管理员（具有适当权限）可以使用 `kubectl certificate approve` 和
`kubectl certificate deny` 命令手动批准（或拒绝）证书签名请求（CSR）。
但是，如果你打算大量使用此 API，则可以考虑编写自动化的证书控制器。

{{< caution >}}
<!-- 
The ability to approve CSRs decides who trusts whom within your environment. The
ability to approve CSRs should not be granted broadly or lightly.

You should make sure that you confidently understand both the verification requirements
that fall on the approver **and** the repercussions of issuing a specific certificate
before you grant the `approve` permission.
-->
批准证书 CSR 的能力决定了在你的环境中谁信任谁。
不应广泛或轻率地授予批准 CSR 的能力。

在授予 `approve` 权限之前，你应该确保自己充分了解批准人的验证要求**和**颁发特定证书的后果。
{{< /caution >}}

<!--
Whether a machine or a human using kubectl as above, the role of the _approver_ is
to verify that the CSR satisfies two requirements:
-->
无论上述机器或人使用 kubectl，“批准者”的作用是验证 CSR 满足如下两个要求：

<!--
1. The subject of the CSR controls the private key used to sign the CSR. This
   addresses the threat of a third party masquerading as an authorized subject.
   In the above example, this step would be to verify that the pod controls the
   private key used to generate the CSR.
2. The subject of the CSR is authorized to act in the requested context. This
   addresses the threat of an undesired subject joining the cluster. In the
   above example, this step would be to verify that the pod is allowed to
   participate in the requested service.
-->
1. CSR 的 subject 控制用于签署 CSR 的私钥。这解决了伪装成授权主体的第三方的威胁。
   在上述示例中，此步骤将验证该 Pod 控制了用于生成 CSR 的私钥。
2. CSR 的 subject 被授权在请求的上下文中执行。
   这点用于处理不期望的主体被加入集群的威胁。
   在上述示例中，此步骤将是验证该 Pod 是否被允许加入到所请求的服务中。

<!--
If and only if these two requirements are met, the approver should approve
the CSR and otherwise should deny the CSR.

For more information on certificate approval and access control, read
the [Certificate Signing Requests](/docs/reference/access-authn-authz/certificate-signing-requests/)
reference page.
-->
当且仅当满足这两个要求时，审批者应该批准 CSR，否则拒绝 CSR。

有关证书批准和访问控制的更多信息，
请阅读[证书签名请求](/zh-cn/docs/reference/access-authn-authz/certificate-signing-requests/)参考页。

<!--
## Configuring your cluster to provide signing

This page assumes that a signer is set up to serve the certificates API. The
Kubernetes controller manager provides a default implementation of a signer. To
enable it, pass the `--cluster-signing-cert-file` and
`--cluster-signing-key-file` parameters to the controller manager with paths to
your Certificate Authority's keypair.
-->
## 给集群管理员的一个建议

本页面假设已经为 certificates API 配置了签名者。
Kubernetes 控制器管理器提供了一个签名者的默认实现。要启用它，请为控制器管理器设置
`--cluster-signing-cert-file` 和 `--cluster-signing-key-file` 参数，
使之取值为你的证书机构的密钥对的路径。