《OpenShift 4.x HOL教程汇总》
说明：本文已经在OpenShift 4.8环境中验证

文章目录

配置签名环境
- 安装镜像签名的Operator
- 为集群指定签名用的 sigstore
测试验证
参考

本文先安装镜像签名 Operator，然后将 docker.io 的镜像导入到 OpenShift 本地，在强制 docker.io 的镜像必须签名。最后使用对来 docker.io 的本地进行签名并运行。

配置签名环境

安装镜像签名的Operator

执行命令下载配置文件

$ git clone https://github.com/liuxiaoyu-git/image-scanning-signing-service.git
$ cd image-scanning-signing-service

为一个worker节点打标签，让它作为运行签名的节点

$ WORKER="$(oc get nodes -l node-role.kubernetes.io/worker --no-headers -o custom-columns=":metadata.name" | head -1)"
$ echo ${WORKER}
$ oc label node ${WORKER} type=builder

查看所有worker节点状态，确认都变成“UPDATED”状态。

$ oc get machineconfigpool -w
NAME     CONFIG                                             UPDATED   UPDATING   DEGRADED   MACHINECOUNT   READYMACHINECOUNT   UPDATEDMACHINECOUNT   DEGRADEDMACHINECOUNT   AGE
master   rendered-master-268f75295029d9dbe6755043c42427b3   True      False      False      3              3                   3                     0                      9d
worker   rendered-worker-8dac6881264caab39329d54ab649abbd   True      False      False      2              2                   2                     0                      9d

创建项目，然后部署 Operator 、签名store及其相关资源。

oc new-project image-management
oc apply -f deploy/crds/imagesigningrequests.cop.redhat.com_imagesigningrequests_crd.yaml
oc apply -f deploy/service_account.yaml
oc apply -f deploy/role.yaml
oc apply -f deploy/role_binding.yaml
oc apply -f deploy/scc.yaml
oc apply -f deploy/secret.yaml
oc apply -f deploy/lab_extras/operator.yaml
oc apply -f deploy/lab_extras/sigstore.yaml

查看部署的pod已经运行。

$ oc get pod -n image-management
NAME                              READY   STATUS      RESTARTS   AGE
image-security-6b9bb96765-4hlp5   1/1     Running     0          21s
sigstore-1-deploy                 0/1     Completed   0          18s
sigstore-1-wh7sj                  1/1     Running     0          16s

为集群指定签名用的 sigstore

获取sigstore的访问route的地址。

$ ROUTE=http://$(oc get route sigstore -o jsonpath='{..spec.host}' -n image-management)

用 $ROUTE 的内容替换 deploy/lab_extras/registry-conf.yaml 文件中的 { {replace_with_sigstore_route}} 部分。
对 deploy/lab_extras/registry-conf.yaml 文件内容进行 base64 编码。

$ base64 deploy/lab_extras/registry-conf.yaml -w 0
ZG9ja2VyOgogICAgIGRvY2tlci5pbzoKICAgICAgICAgc2lnc3RvcmU6IGh0dHA6Ly9zaWdzdG9yZS1pbWFnZS1tYW5hZ2VtZW50LmFwcHMuY2x1c3Rlci04ZDM1LjhkMzUuc2FuZGJveDE0MjAub3BlbnRsYy5jb20gCg==

用上一步返回的字符串结果替换 deploy/lab_extras/trust-machineconifg.yaml 文件中的 { {token}} 部分。
执行命令更新 worker节点，然后查看 worker 的 machineconfigpools 的状态，直到 READYMACHINECOUNT 状态都恢复成正常数量。

$ oc apply -f deploy/lab_extras/trust-machineconifg.yaml
$ oc get machineconfigpool worker -w
NAME     CONFIG                                             UPDATED   UPDATING   DEGRADED   MACHINECOUNT   READYMACHINECOUNT   UPDATEDMACHINECOUNT   DEGRADEDMACHINECOUNT   AGE
worker   rendered-worker-8dac6881264caab39329d54ab649abbd   False     True       False      2              0                   0                     0                      9d
worker   rendered-worker-8dac6881264caab39329d54ab649abbd   False     True       False      2              1                   1                     0                      9d
worker   rendered-worker-8dac6881264caab39329d54ab649abbd   False     True       False      2              1                   1                     0                      9d
worker   rendered-worker-d977c1330ccf9a645aca738a56abe8af   True      False      False      2              2                   2                     0                      9d

测试验证

使用未签名的镜像

进入一个 worker 节点。

$ WORKER="$(oc get nodes -l node-role.kubernetes.io/worker --no-headers -o custom-columns=":metadata.name" | head -1)"
$ oc debug node/${WORKER}
Starting pod/ip-10-0-156-171us-east-2computeinternal-debug ...
To use host binaries, run `chroot /host`
Pod IP: 10.0.156.171
If you don't see a command prompt, try pressing enter.
sh-4.4# chroot /host

查看 /etc/containers/policy.json 和 /etc/containers/registries.d/docker.io.yaml 文件内容，其中包含“docker.io”和“sigstore”相关内容。

sh-4.4# cat /etc/containers/policy.json
{
    "default": [
        {
            "type": "insecureAcceptAnything"
        }
    ],
    "transports": {
        "docker": {
    "docker.io": [
    {
        "type": "signedBy",
        "keyType": "GPGKeys",
        "keyPath": "/root/pubkey.gpg"
    }
]
},
        "docker-daemon": {
    "": [
    {
        "type": "insecureAcceptAnything"
    }
]
}
    }
} 
 
sh-4.4# cat /etc/containers/registries.d/docker.io.yaml
docker:
     docker.io:
         sigstore: http://sigstore-image-management.apps.cluster-8d35.8d35.sandbox1420.opentlc.com

从 “docker.io” 拉镜像，确认提示“** A signature was required, but no signature exists**”。

sh-4.4# podman pull docker.io/library/mysql
Trying to pull docker.io/library/mysql:latest...
Error: Source image rejected: A signature was required, but no signature exists

退出 worker

sh-4.4# exit

运行为签名镜像

创建新项目，然后将来自 “docker.io” 的镜像测试镜像导入到本地，最后基于它创建新应用。

$ oc new-project nginx-test
$ oc import-image nginx --from="docker.io/nginxinc/nginx-unprivileged" --confirm -n nginx-test
$ oc new-app nginx -n nginx-test

查看应用 pod 状态，确认是“ImagePullBackOff” 状态

$ oc get pod -n nginx-test
NAME                    READY   STATUS             RESTARTS   AGE
nginx-9dd546c49-wp682   0/1     ImagePullBackOff   0          25s

查看上一步的 pod 的状态，确认在 Events 中提示“image rejected: A signature was required, but no signature exists”。

$ oc describe pod nginx-9dd546c49-wp682 -n nginx-test
。。。。
Events:
  Type     Reason          Age                 From               Message
  ----     ------          ----                ----               -------
  Normal   Scheduled       109s                default-scheduler  Successfully assigned nginx-test/nginx-9dd546c49-wp682 to ip-10-0-170-27.us-east-2.compute.internal
  Normal   AddedInterface  108s                multus             Add eth0 [10.131.0.18/23] from openshift-sdn
  Warning  Failed          30s (x6 over 107s)  kubelet            Error: ImagePullBackOff
  Normal   Pulling         15s (x4 over 108s)  kubelet            Pulling image "docker.io/nginxinc/nginx-unprivileged@sha256:ed41d4160dd6bf386f5e611a44f6d5467c83e26bb131b459a34459fc5a42e052"
  Warning  Failed          15s (x4 over 108s)  kubelet            Failed to pull image "docker.io/nginxinc/nginx-unprivileged@sha256:ed41d4160dd6bf386f5e611a44f6d5467c83e26bb131b459a34459fc5a42e052": rpc error: code = Unknown desc = Source image rejected: A signature was required, but no signature exists
  Warning  Failed          15s (x4 over 108s)  kubelet            Error: ErrImagePull
  Normal   BackOff         1s (x7 over 107s)   kubelet            Back-off pulling image "docker.io/nginxinc/nginx-unprivileged@sha256:ed41d4160dd6bf386f5e611a44f6d5467c83e26bb131b459a34459fc5a42e052"

对本地镜像签名

查看 deploy/lab_extras/signing-request.yaml 文件内容，它发出对名为 “nginx:latest” 的 ImageStreamTag 的镜像进行签名的请求。

$ more deploy/lab_extras/signing-request.yaml
apiVersion: imagesigningrequests.cop.redhat.com/v1alpha1
kind: ImageSigningRequest
metadata:
  name: nginx-1
spec:
  containerImage:
    kind: ImageStreamTag
    name: nginx:latest
$ oc apply -f deploy/lab_extras/signing-request.yaml -n nginx-test

查看 image-management 的 pod，然后查看名称随机生成的 pod 日志，

$ oc get pod -n image-management
NAME                                   READY   STATUS      RESTARTS   AGE
c3b5f7ff-d047-4f62-a0eb-c57a469cbfab   0/1     Completed   0          57s
image-security-6b9bb96765-hvnvr        1/1     Running     0          9m26s
sigstore-1-m2cq7                       1/1     Running     0          13m
$ oc logs -f c3b5f7ff-d047-4f62-a0eb-c57a469cbfab -n image-management
time="2021-11-12T14:28:15Z" level=error msg="unable to write system event: \"write unixgram @00016->/run/systemd/journal/socket: sendmsg: no such file or directory\""
Trying to pull docker.io/nginxinc/nginx-unprivileged@sha256:ed41d4160dd6bf386f5e611a44f6d5467c83e26bb131b459a34459fc5a42e052...
Getting image source signatures
Copying blob sha256:54247d3512a9e6bc95687e0b652e10044079c9bbf7af9d69fa1d428e41bff84f
Copying blob sha256:0f7e43c994f13c51289d21fc1a72d13fed47631a99ce7b524dfe8d1a45958477
Copying blob sha256:052722e881c1465eb58c9ac2bafc164a254188c9f06bd0933d99757ec992fc00
Copying blob sha256:a330b6cecb98cd2425fd25fce36669073f593b3176b4ee14731e48c05d678cdd
Copying blob sha256:96bc90d52cf2f2f47520455d64faad604a264bcaa579617419087d59b9f84461
Copying blob sha256:3aeee11385fd3301401d6e72c873fcbb9e7dc1a486e793d76d62b0034a27ac3a
Copying blob sha256:5885822443274cc7a636331e79ae9909810cfbe9344c1b93abfc8a78b9e35a3a
Copying config sha256:9f271e225e01a0a3868f080ae7cfaf36a957a79f8141c96c5604352e9629729e
Writing manifest to image destination
Storing signatures
9f271e225e01a0a3868f080ae7cfaf36a957a79f8141c96c5604352e9629729e
Untagged: docker.io/nginxinc/nginx-unprivileged@sha256:ed41d4160dd6bf386f5e611a44f6d5467c83e26bb131b459a34459fc5a42e052
Deleted: 9f271e225e01a0a3868f080ae7cfaf36a957a79f8141c96c5604352e9629729e

查看签名请求对象，其中在 “status” 中有 “message: Image Signed” 。

$ oc get imagesigningrequests nginx-1 -o yaml -n nginx-test
。。。
status:
  conditions:
 - lastTransitionTime: 2021-11-12 14:27:51.956766002 +0000 UTC m=+487.950431898
    message: Signing Pod Launched 'image-management/c3b5f7ff-d047-4f62-a0eb-c57a469cbfab'
    status: "True"
    type: Initialization
 - lastTransitionTime: 2021-11-12 14:28:41.161360642 +0000 UTC m=+537.155026498
    message: Image Signed
    status: "True"
    type: Finished
  endTime: 2021-11-12 14:28:41.161360642 +0000 UTC m=+537.155026498
  phase: Completed
  signedImage: sha256:ed41d4160dd6bf386f5e611a44f6d5467c83e26bb131b459a34459fc5a42e052
  startTime: 2021-11-12 14:27:51.956766002 +0000 UTC m=+487.950431898
  unsignedImage: sha256:ed41d4160dd6bf386f5e611a44f6d5467c83e26bb131b459a34459fc5a42e052

再次查看 nginx-test 项目中的 pod，确认现在是 Running 状态了。如果没有自动部署，可以重新部署一次。

$ oc get pod -n nginx-test
NAME                    READY   STATUS    RESTARTS   AGE
nginx-9dd546c49-wp682   1/1     Running   0          9m28s
$ oc rollout restart deployment/nginx
deployment.apps/nginx restarted

可以用浏览器访问“${ROUTE}/nginxinc”，其中包含签名用的“sigstore”文件。

参考

https://github.com/RedHatDemos/SecurityDemos/blob/master/2021Labs/OpenShiftSecurity/documentation/lab5.adoc
https://github.com/redhat-cop/image-scanning-signing-service.git
https://access.redhat.com/verify-images-ocp4

OpenShift 4 - 为集群配置镜像签名功能，只能运行被签名的本地镜像