2.4. 容器镜像签名
红帽为 Red Hat Container Registries 中的镜像提供签名。在使用 Machine Config Operator（MCO）拉取到 OpenShift Container Platform 4 集群时，会自动验证这些签名。
Quay.io 提供了组成 OpenShift Container Platform 的大多数镜像，只有发行镜像会被签名。发行镜像指的是批准的 OpenShift Container Platform 镜像，它可以对供应链攻击提供一定程度的保护。但是，OpenShift Container Platform 的一些扩展（如日志记录、监控和服务网格）会作为 Operator Lifecycle Manager（OLM）的 Operator 提供。这些镜像来自 红帽生态系统目录容器镜像 registry。
要验证这些镜像在红帽 registry 和您的基础架构间的完整性，启用签名验证。
2.4.1. 为 Red Hat Container registry 启用签名验证
为 Red Hat Container Registries 启用容器签名验证需要编写签名验证策略文件，指定从这些 registry 中验证镜像的密钥。对于 RHEL8 节点，默认已在 /etc/containers/registries.d 中定义 registry。
流程
创建 Butane 配置文件
51-worker-rh-registry-trust.bu，其中包含 worker 节点的必要配置。注意如需有关 Butane 的信息，请参阅"使用 Butane 创建机器配置"。
variant: openshift version: 4.8.0 metadata: name: 51-worker-rh-registry-trust labels: machineconfiguration.openshift.io/role: worker storage: files: - path: /etc/containers/policy.json mode: 0644 overwrite: true contents: inline: | { "default": [ { "type": "insecureAcceptAnything" } ], "transports": { "docker": { "registry.access.redhat.com": [ { "type": "signedBy", "keyType": "GPGKeys", "keyPath": "/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release" } ], "registry.redhat.io": [ { "type": "signedBy", "keyType": "GPGKeys", "keyPath": "/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release" } ] }, "docker-daemon": { "": [ { "type": "insecureAcceptAnything" } ] } } }使用 Butane 生成机器配置 YAML 文件
51-worker-rh-registry-trust.yaml，其中包含要写入 worker 节点上的磁盘的文件：$ butane 51-worker-rh-registry-trust.bu -o 51-worker-rh-registry-trust.yaml
应用创建的机器配置：
$ oc apply -f 51-worker-rh-registry-trust.yaml
检查 worker 机器配置池已使用新机器配置推出：
检查是否创建了新机器配置：
$ oc get mc
输出示例
NAME GENERATEDBYCONTROLLER IGNITIONVERSION AGE 00-master a2178ad522c49ee330b0033bb5cb5ea132060b0a 3.2.0 25m 00-worker a2178ad522c49ee330b0033bb5cb5ea132060b0a 3.2.0 25m 01-master-container-runtime a2178ad522c49ee330b0033bb5cb5ea132060b0a 3.2.0 25m 01-master-kubelet a2178ad522c49ee330b0033bb5cb5ea132060b0a 3.2.0 25m 01-worker-container-runtime a2178ad522c49ee330b0033bb5cb5ea132060b0a 3.2.0 25m 01-worker-kubelet a2178ad522c49ee330b0033bb5cb5ea132060b0a 3.2.0 25m 51-master-rh-registry-trust 3.2.0 13s 51-worker-rh-registry-trust 3.2.0 53s 1 99-master-generated-crio-seccomp-use-default 3.2.0 25m 99-master-generated-registries a2178ad522c49ee330b0033bb5cb5ea132060b0a 3.2.0 25m 99-master-ssh 3.2.0 28m 99-worker-generated-crio-seccomp-use-default 3.2.0 25m 99-worker-generated-registries a2178ad522c49ee330b0033bb5cb5ea132060b0a 3.2.0 25m 99-worker-ssh 3.2.0 28m rendered-master-af1e7ff78da0a9c851bab4be2777773b a2178ad522c49ee330b0033bb5cb5ea132060b0a 3.2.0 8s rendered-master-cd51fd0c47e91812bfef2765c52ec7e6 a2178ad522c49ee330b0033bb5cb5ea132060b0a 3.2.0 24m rendered-worker-2b52f75684fbc711bd1652dd86fd0b82 a2178ad522c49ee330b0033bb5cb5ea132060b0a 3.2.0 24m rendered-worker-be3b3bce4f4aa52a62902304bac9da3c a2178ad522c49ee330b0033bb5cb5ea132060b0a 3.2.0 48s 2
检查 worker 机器配置池是否使用新机器配置更新：
$ oc get mcp
输出示例
NAME CONFIG UPDATED UPDATING DEGRADED MACHINECOUNT READYMACHINECOUNT UPDATEDMACHINECOUNT DEGRADEDMACHINECOUNT AGE master rendered-master-af1e7ff78da0a9c851bab4be2777773b True False False 3 3 3 0 30m worker rendered-worker-be3b3bce4f4aa52a62902304bac9da3c False True False 3 0 0 0 30m 1- 1
- 当
UPDATING字段为True时，机器配置池会使用新机器配置进行更新。当字段变为False时，代表 worker 机器配置池已应用到新机器配置。
如果您的集群使用任何 RHEL7 worker 节点，当 worker 机器配置池被更新时，在
/etc/containers/registries.d目录中在这些节点上创建 YAML 文件，用于指定给定 registry 服务器的分离签名的位置。以下示例只适用于托管在registry.access.redhat.com和registry.redhat.io中的镜像。为每个 RHEL7 worker 节点启动一个 debug 会话：
$ oc debug node/<node_name>
将您的根目录改为
/host：sh-4.2# chroot /host
创建一个包含以下内容的
/etc/containers/registries.d/registry.redhat.io.yaml文件：docker: registry.redhat.io: sigstore: https://registry.redhat.io/containers/sigstore创建一个包含以下内容的
/etc/containers/registries.d/registry.access.redhat.com.yaml文件：docker: registry.access.redhat.com: sigstore: https://access.redhat.com/webassets/docker/content/sigstore- 退出 debug 会话。
2.4.2. 验证签名验证配置
将机器配置应用到集群后，Machine Config Controller 会检测到新的 MachineConfig 对象，并生成新的 rendered-worker-<hash> 版本。
先决条件
- 您可以使用机器配置文件启用签名验证。
流程
在命令行中运行以下命令显示所需 worker 的信息：
$ oc describe machineconfigpool/worker
初始 worker 监控的输出示例
Name: worker Namespace: Labels: machineconfiguration.openshift.io/mco-built-in= Annotations: <none> API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfigPool Metadata: Creation Timestamp: 2019-12-19T02:02:12Z Generation: 3 Resource Version: 16229 Self Link: /apis/machineconfiguration.openshift.io/v1/machineconfigpools/worker UID: 92697796-2203-11ea-b48c-fa163e3940e5 Spec: Configuration: Name: rendered-worker-f6819366eb455a401c42f8d96ab25c02 Source: API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfig Name: 00-worker API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfig Name: 01-worker-container-runtime API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfig Name: 01-worker-kubelet API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfig Name: 51-worker-rh-registry-trust API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfig Name: 99-worker-92697796-2203-11ea-b48c-fa163e3940e5-registries API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfig Name: 99-worker-ssh Machine Config Selector: Match Labels: machineconfiguration.openshift.io/role: worker Node Selector: Match Labels: node-role.kubernetes.io/worker: Paused: false Status: Conditions: Last Transition Time: 2019-12-19T02:03:27Z Message: Reason: Status: False Type: RenderDegraded Last Transition Time: 2019-12-19T02:03:43Z Message: Reason: Status: False Type: NodeDegraded Last Transition Time: 2019-12-19T02:03:43Z Message: Reason: Status: False Type: Degraded Last Transition Time: 2019-12-19T02:28:23Z Message: Reason: Status: False Type: Updated Last Transition Time: 2019-12-19T02:28:23Z Message: All nodes are updating to rendered-worker-f6819366eb455a401c42f8d96ab25c02 Reason: Status: True Type: Updating Configuration: Name: rendered-worker-d9b3f4ffcfd65c30dcf591a0e8cf9b2e Source: API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfig Name: 00-worker API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfig Name: 01-worker-container-runtime API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfig Name: 01-worker-kubelet API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfig Name: 99-worker-92697796-2203-11ea-b48c-fa163e3940e5-registries API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfig Name: 99-worker-ssh Degraded Machine Count: 0 Machine Count: 1 Observed Generation: 3 Ready Machine Count: 0 Unavailable Machine Count: 1 Updated Machine Count: 0 Events: <none>再次运行
oc describe命令：$ oc describe machineconfigpool/worker
worker 更新后的输出示例
... Last Transition Time: 2019-12-19T04:53:09Z Message: All nodes are updated with rendered-worker-f6819366eb455a401c42f8d96ab25c02 Reason: Status: True Type: Updated Last Transition Time: 2019-12-19T04:53:09Z Message: Reason: Status: False Type: Updating Configuration: Name: rendered-worker-f6819366eb455a401c42f8d96ab25c02 Source: API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfig Name: 00-worker API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfig Name: 01-worker-container-runtime API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfig Name: 01-worker-kubelet API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfig Name: 51-worker-rh-registry-trust API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfig Name: 99-worker-92697796-2203-11ea-b48c-fa163e3940e5-registries API Version: machineconfiguration.openshift.io/v1 Kind: MachineConfig Name: 99-worker-ssh Degraded Machine Count: 0 Machine Count: 3 Observed Generation: 4 Ready Machine Count: 3 Unavailable Machine Count: 0 Updated Machine Count: 3 ...注意Observed Generation参数显示基于控制器生成的配置的生成数量的增加数。此控制器即使没有处理规格并生成修订，也会更新这个值。Configuration Source值指向51-worker-rh-registry-trust配置。使用以下命令确认
policy.json文件已存在：$ oc debug node/<node> -- chroot /host cat /etc/containers/policy.json
输出示例
Starting pod/<node>-debug ... To use host binaries, run `chroot /host` { "default": [ { "type": "insecureAcceptAnything" } ], "transports": { "docker": { "registry.access.redhat.com": [ { "type": "signedBy", "keyType": "GPGKeys", "keyPath": "/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release" } ], "registry.redhat.io": [ { "type": "signedBy", "keyType": "GPGKeys", "keyPath": "/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release" } ] }, "docker-daemon": { "": [ { "type": "insecureAcceptAnything" } ] } } }使用以下命令确认
registry.redhat.io.yaml文件已存在：$ oc debug node/<node> -- chroot /host cat /etc/containers/registries.d/registry.redhat.io.yaml
输出示例
Starting pod/<node>-debug ... To use host binaries, run `chroot /host` docker: registry.redhat.io: sigstore: https://registry.redhat.io/containers/sigstore使用以下命令确认
registry.access.redhat.com.yaml文件已存在：$ oc debug node/<node> -- chroot /host cat /etc/containers/registries.d/registry.access.redhat.com.yaml
输出示例
Starting pod/<node>-debug ... To use host binaries, run `chroot /host` docker: registry.access.redhat.com: sigstore: https://access.redhat.com/webassets/docker/content/sigstore
