413 lines
14 KiB
Markdown
413 lines
14 KiB
Markdown
---
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title: 管理集群中的 TLS 认证
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content_type: task
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reviewers:
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- mikedanese
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- beacham
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- liggit
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---
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<!--
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---
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title: Manage TLS Certificates in a Cluster
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content_type: task
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reviewers:
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- mikedanese
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- beacham
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- liggit
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---
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-->
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<!-- overview -->
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<!--
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Kubernetes provides a `certificates.k8s.io` API, which lets you provision TLS
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certificates signed by a Certificate Authority (CA) that you control. These CA
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and certificates can be used by your workloads to establish trust.
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`certificates.k8s.io` API uses a protocol that is similar to the [ACME
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draft](https://github.com/ietf-wg-acme/acme/).
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-->
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Kubernetes提供一个 `certificates.k8s.io` API，可让您配置
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由您控制的证书颁发机构（CA）签名的TLS证书。 您的工作负载可以使用这些CA和证书来建立信任。
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`certificates.k8s.io` API使用的协议类似于[ACME
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草稿](https://github.com/ietf-wg-acme/acme/)。
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{{< note >}}
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<!--
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Certificates created using the `certificates.k8s.io` API are signed by a
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dedicated CA. It is possible to configure your cluster to use the cluster root
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CA for this purpose, but you should never rely on this. Do not assume that
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these certificates will validate against the cluster root CA.
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-->
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使用`certificates.k8s.io` API创建的证书由
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指定 CA 颁发。 将集群配置为使用集群根目录
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CA 可以达到这个目的，但是您永远不要依赖它。不要以为
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这些证书将针对群根目录 CA 进行验证。
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{{< /note >}}
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## {{% heading "prerequisites" %}}
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{{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
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<!-- steps -->
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<!--
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## Trusting TLS in a Cluster
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Trusting the cluster root CA from an application running as a pod usually
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requires some extra application configuration. You will need to add the CA
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certificate bundle to the list of CA certificates that the TLS client or server
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trusts. For example, you would do this with a golang TLS config by parsing the
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certificate chain and adding the parsed certificates to the `RootCAs` field
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in the [`tls.Config`](https://godoc.org/crypto/tls#Config) struct.
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The CA certificate bundle is automatically mounted into pods using the default
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service account at the path `/var/run/secrets/kubernetes.io/serviceaccount/ca.crt`.
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If you are not using the default service account, ask a cluster administrator to
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build a configmap containing the certificate bundle that you have access to use.
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-->
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## 集群中的 TLS 信任
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让 Pod 中运行的应用程序信任集群根 CA 通常需要一些额外的应用程序配置。您将需要将 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，您可以使用 golang TLS 配置通过解析证书链并将解析的证书添加到 [`tls.Config`](https://godoc.org/crypto/tls#Config) 结构中的 `RootCAs` 字段中。
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CA 证书捆绑包将使用默认服务账户自动加载到 pod 中，路径为 `/var/run/secrets/kubernetes.io/serviceaccount/ca.crt`。如果您没有使用默认服务账户，请请求集群管理员构建包含您有权访问使用的证书包的 configmap。
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<!--
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## Requesting a Certificate
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The following section demonstrates how to create a TLS certificate for a
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Kubernetes service accessed through DNS.
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{{< note >}}
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This tutorial uses CFSSL: Cloudflare's PKI and TLS toolkit [click here](https://blog.cloudflare.com/introducing-cfssl/) to know more.
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{{< /note >}}
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-->
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## 请求认证
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以下部分演示如何为通过 DNS 访问的 Kubernetes 服务创建 TLS 证书。
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{{< note >}}
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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。
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{{< /note >}}
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<!--
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## Download and install CFSSL
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The cfssl tools used in this example can be downloaded at
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[https://pkg.cfssl.org/](https://pkg.cfssl.org/).
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-->
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## 下载并安装 CFSSL
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本例中使用的 cfssl 工具可以在 [https://pkg.cfssl.org/](https://pkg.cfssl.org/) 下载。
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<!--
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## Create a Certificate Signing Request
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Generate a private key and certificate signing request (or CSR) by running
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the following command:
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```shell
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cat <<EOF | cfssl genkey - | cfssljson -bare server
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{
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"hosts": [
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"my-svc.my-namespace.svc.cluster.local",
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"my-pod.my-namespace.pod.cluster.local",
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"172.168.0.24",
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"10.0.34.2"
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],
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"CN": "my-pod.my-namespace.pod.cluster.local",
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"key": {
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"algo": "ecdsa",
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"size": 256
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}
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}
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EOF
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```
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Where `172.168.0.24` is the service's cluster IP,
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`my-svc.my-namespace.svc.cluster.local` is the service's DNS name,
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`10.0.34.2` is the pod's IP and `my-pod.my-namespace.pod.cluster.local`
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is the pod's DNS name. You should see the following output:
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```
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2017/03/21 06:48:17 [INFO] generate received request
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2017/03/21 06:48:17 [INFO] received CSR
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2017/03/21 06:48:17 [INFO] generating key: ecdsa-256
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2017/03/21 06:48:17 [INFO] encoded CSR
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```
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This command generates two files; it generates `server.csr` containing the PEM
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encoded [pkcs#10](https://tools.ietf.org/html/rfc2986) certification request,
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and `server-key.pem` containing the PEM encoded key to the certificate that
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is still to be created.
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-->
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## 创建证书签名请求
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通过运行以下命令生成私钥和证书签名请求（或 CSR）:
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```shell
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cat <<EOF | cfssl genkey - | cfssljson -bare server
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{
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"hosts": [
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"my-svc.my-namespace.svc.cluster.local",
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"my-pod.my-namespace.pod.cluster.local",
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"172.168.0.24",
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"10.0.34.2"
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],
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"CN": "my-pod.my-namespace.pod.cluster.local",
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"key": {
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"algo": "ecdsa",
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"size": 256
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}
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}
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EOF
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```
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其中 `172.168.0.24` 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 和 `my-pod.my-namespace.pod.cluster.local` 是 pod 的 DNS 名称。您能看到以下的输出：
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```
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2017/03/21 06:48:17 [INFO] generate received request
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2017/03/21 06:48:17 [INFO] received CSR
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2017/03/21 06:48:17 [INFO] generating key: ecdsa-256
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2017/03/21 06:48:17 [INFO] encoded CSR
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```
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该命令生成两个文件；它生成包含 PEM 编码 [pkcs#10](https://tools.ietf.org/html/rfc2986) 认证请求的 `server.csr`，以及包含证书的 PEM 编码密钥的 `server-key.pem` 还有待生成。
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<!--
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## Create a Certificate Signing Request object to send to the Kubernetes API
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Generate a CSR yaml blob and send it to the apiserver by running the following
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command:
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```shell
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cat <<EOF | kubectl apply -f -
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apiVersion: certificates.k8s.io/v1beta1
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kind: CertificateSigningRequest
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metadata:
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name: my-svc.my-namespace
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spec:
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groups:
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- system:authenticated
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request: $(cat server.csr | base64 | tr -d '\n')
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usages:
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- digital signature
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- key encipherment
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- server auth
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EOF
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```
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Notice that the `server.csr` file created in step 1 is base64 encoded
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and stashed in the `.spec.request` field. We are also requesting a
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certificate with the "digital signature", "key encipherment", and "server
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auth" key usages. We support all key usages and extended key usages listed
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[here](https://godoc.org/k8s.io/api/certificates/v1beta1#KeyUsage)
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so you can request client certificates and other certificates using this
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same API.
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The CSR should now be visible from the API in a Pending state. You can see
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it by running:
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```shell
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kubectl describe csr my-svc.my-namespace
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```
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```none
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Name: my-svc.my-namespace
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Labels: <none>
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Annotations: <none>
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CreationTimestamp: Tue, 21 Mar 2017 07:03:51 -0700
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Requesting User: yourname@example.com
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Status: Pending
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Subject:
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Common Name: my-svc.my-namespace.svc.cluster.local
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Serial Number:
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Subject Alternative Names:
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DNS Names: my-svc.my-namespace.svc.cluster.local
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IP Addresses: 172.168.0.24
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10.0.34.2
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Events: <none>
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```
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-->
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## 创建证书签名请求对象发送到 Kubernetes API
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使用以下命令创建 CSR yaml 文件，并发送到 API server：
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```shell
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cat <<EOF | kubectl apply -f -
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apiVersion: certificates.k8s.io/v1beta1
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kind: CertificateSigningRequest
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metadata:
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name: my-svc.my-namespace
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spec:
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groups:
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- system:authenticated
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request: $(cat server.csr | base64 | tr -d '\n')
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usages:
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- digital signature
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- key encipherment
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- server auth
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EOF
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```
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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，我们还要求提供 “数字签名”，“密钥加密” 和 “服务器身份验证” 密钥用途的证书。我们[这里](https://godoc.org/k8s.io/api/certificates/v1beta1#KeyUsage)支持列出的所有关键用途和扩展的关键用途，以便您可以使用相同的 API 请求客户端证书和其他证书。
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在 API server 中可以看到这些 CSR 处于 pending 状态。执行下面的命令您将可以看到：
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```shell
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kubectl describe csr my-svc.my-namespace
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```
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```none
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Name: my-svc.my-namespace
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Labels: <none>
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Annotations: <none>
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CreationTimestamp: Tue, 21 Mar 2017 07:03:51 -0700
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Requesting User: yourname@example.com
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Status: Pending
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Subject:
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Common Name: my-svc.my-namespace.svc.cluster.local
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Serial Number:
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Subject Alternative Names:
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DNS Names: my-svc.my-namespace.svc.cluster.local
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IP Addresses: 172.168.0.24
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10.0.34.2
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Events: <none>
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```
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<!--
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## Get the Certificate Signing Request Approved
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Approving the certificate signing request is either done by an automated
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approval process or on a one off basis by a cluster administrator. More
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information on what this involves is covered below.
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-->
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## 获取批准的证书签名请求
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批准证书签名请求是通过自动批准过程完成的，或由集群管理员一次性完成。有关这方面涉及的更多信息，请参见下文。
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<!--
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## Download the Certificate and Use It
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Once the CSR is signed and approved you should see the following:
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```shell
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kubectl get csr
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```
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```none
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NAME AGE REQUESTOR CONDITION
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my-svc.my-namespace 10m yourname@example.com Approved,Issued
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```
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You can download the issued certificate and save it to a `server.crt` file
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by running the following:
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```shell
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kubectl get csr my-svc.my-namespace -o jsonpath='{.status.certificate}' \
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| base64 --decode > server.crt
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```
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Now you can use `server.crt` and `server-key.pem` as the keypair to start
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your HTTPS server.
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-->
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## 下载证书并使用它
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CSR 被签署并获得批准后，您应该看到以下内容：
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```shell
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kubectl get csr
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```
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```none
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NAME AGE REQUESTOR CONDITION
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my-svc.my-namespace 10m yourname@example.com Approved,Issued
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```
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您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：
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```shell
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kubectl get csr my-svc.my-namespace -o jsonpath='{.status.certificate}' \
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| base64 --decode > server.crt
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```
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现在您可以将 `server.crt` 和 `server-key.pem` 作为键值对来启动 HTTPS 服务器。
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<!--
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## Approving Certificate Signing Requests
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A Kubernetes administrator (with appropriate permissions) can manually approve
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(or deny) Certificate Signing Requests by using the `kubectl certificate
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approve` and `kubectl certificate deny` commands. However if you intend
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to make heavy usage of this API, you might consider writing an automated
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certificates controller.
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Whether a machine or a human using kubectl as above, the role of the approver is
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to verify that the CSR satisfies two requirements:
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1. The subject of the CSR controls the private key used to sign the CSR. This
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addresses the threat of a third party masquerading as an authorized subject.
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In the above example, this step would be to verify that the pod controls the
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private key used to generate the CSR.
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2. The subject of the CSR is authorized to act in the requested context. This
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addresses the threat of an undesired subject joining the cluster. In the
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above example, this step would be to verify that the pod is allowed to
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participate in the requested service.
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If and only if these two requirements are met, the approver should approve
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the CSR and otherwise should deny the CSR.
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-->
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## 批准证书签名请求
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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。但是，如果您打算大量使用此 API，则可以考虑编写自动化的证书控制器。
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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：
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1. CSR 的主体控制用于签署 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。
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2. CSR 的主体被授权在请求的上下文中执行。这解决了我们加入群集的我们不期望的主体的威胁。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。
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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。
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<!--
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## A Word of Warning on the Approval Permission
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The ability to approve CSRs decides who trusts who within the cluster. This
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includes who the Kubernetes API trusts. The ability to approve CSRs should
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not be granted broadly or lightly. The requirements of the challenge
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noted in the previous section and the repercussions of issuing a specific
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certificate should be fully understood before granting this permission. See
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[here](/docs/reference/access-authn-authz/authentication/#x509-client-certs) for information on how
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certificates interact with authentication.
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-->
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## 关于批准许可的警告
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批准 CSR 的能力决定谁信任群集中的谁。这包括 Kubernetes API 信任的人。批准 CSR 的能力不能过于广泛和轻率。在给予本许可之前，应充分了解上一节中提到的挑战和发布特定证书的后果。有关证书与认证交互的信息，请参阅[此处](/docs/reference/access-authn-authz/authentication/#x509-client-certs)。
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<!--
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## A Note to Cluster Administrators
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This tutorial assumes that a signer is setup to serve the certificates API. The
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Kubernetes controller manager provides a default implementation of a signer. To
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enable it, pass the `--cluster-signing-cert-file` and
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`--cluster-signing-key-file` parameters to the controller manager with paths to
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your Certificate Authority's keypair.
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-->
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## 给集群管理员的一个建议
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本教程假设将签名者设置为服务证书 API。Kubernetes controller manager 提供了一个签名者的默认实现。 要启用它，请将`--cluster-signing-cert-file` 和 `--cluster-signing-key-file` 参数传递给 controller manager，并配置具有证书颁发机构的密钥对的路径。
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