kubernetes|Kubernetes K8S之存储Secret详解

K8S之存储Secret概述与类型说明,并详解常用Secret示例
主机配置规划
服务器名称(hostname) 系统版本 配置 内网IP 外网IP(模拟)
k8s-master CentOS7.7 2C/4G/20G 172.16.1.110 10.0.0.110
k8s-node01 CentOS7.7 2C/4G/20G 172.16.1.111 10.0.0.111
k8s-node02 CentOS7.7 2C/4G/20G 172.16.1.112 10.0.0.112
Secret概述 Secret解决了密码、token、秘钥等敏感数据的配置问题,而不需要把这些敏感数据暴露到镜像或者Pod Spec中。Secret可以以Volume或者环境变量的方式使用
用户可以创建 secret,同时系统也创建了一些 secret。
要使用 secret,pod 需要引用 secret。Pod 可以用两种方式使用 secret:作为 volume 中的文件被挂载到 pod 中的一个或者多个容器里,或者当 kubelet 为 pod 拉取镜像时使用。
Secret类型
  • Service Account:用来访问Kubernetes API,由Kubernetes自动创建,并且会自动挂载到Pod的 /run/secrets/kubernetes.io/serviceaccount 目录中。
  • Opaque:base64编码格式的Secret,用来存储密码、秘钥等。
  • kubernetes.io/dockerconfigjson:用来存储私有docker registry的认证信息。
Service Account 通过kube-proxy查看
[root@k8s-master ~]# kubectl get pod -A | grep 'kube-proxy' kube-systemkube-proxy-6bfh71/1Running127d3h kube-systemkube-proxy-6vfkf1/1Running117d3h kube-systemkube-proxy-bvl9n1/1Running117d3h [root@k8s-master ~]# [root@k8s-master ~]# kubectl exec -it -n kube-system kube-proxy-6bfh7 -- /bin/sh # ls -l /run/secrets/kubernetes.io/serviceaccount total 0 lrwxrwxrwx 1 root root 13 Jun8 13:39 ca.crt -> ..data/ca.crt lrwxrwxrwx 1 root root 16 Jun8 13:39 namespace -> ..data/namespace lrwxrwxrwx 1 root root 12 Jun8 13:39 token -> ..data/token

Opaque Secret 创建secret 手动加密,基于base64加密
[root@k8s-master ~]# echo -n 'admin' | base64 YWRtaW4= [root@k8s-master ~]# echo -n '1f2d1e2e67df' | base64 MWYyZDFlMmU2N2Rm

yaml文件
[root@k8s-master secret]# pwd /root/k8s_practice/secret [root@k8s-master secret]# cat secret.yaml apiVersion: v1 kind: Secret metadata: name: mysecret type: Opaque data: username: YWRtaW4= password: MWYyZDFlMmU2N2Rm

或者通过如下命令行创建【secret名称故意设置不一样,以方便查看对比】,生成secret后会自动加密,而非明文存储。
kubectl create secret generic db-user-pass --from-literal=username=admin --from-literal=password=1f2d1e2e67df

生成secret,并查看状态
[root@k8s-master secret]# kubectl apply -f secret.yaml secret/mysecret created [root@k8s-master secret]# [root@k8s-master secret]# kubectl get secret### 查看默认名称空间的secret简要信息 NAMETYPEDATAAGE basic-authOpaque12d12h default-token-v48g4kubernetes.io/service-account-token327d mysecretOpaque223s### 可见已创建 tls-secretkubernetes.io/tls23d2h [root@k8s-master secret]# [root@k8s-master secret]# kubectl get secret mysecret -o yaml### 查看mysecret详细信息 apiVersion: v1 data: password: MWYyZDFlMmU2N2Rm username: YWRtaW4= kind: Secret metadata: annotations: kubectl.kubernetes.io/last-applied-configuration: | {"apiVersion":"v1","data":{"password":"MWYyZDFlMmU2N2Rm","username":"YWRtaW4="},"kind":"Secret","metadata":{"annotations":{},"name":"mysecret","namespace":"default"},"type":"Opaque"} creationTimestamp: "2020-06-08T14:08:59Z" name: mysecret namespace: default resourceVersion: "987419" selfLink: /api/v1/namespaces/default/secrets/mysecret uid: 27b58929-71c4-495b-99a5-0d411910a529 type: Opaque [root@k8s-master secret]# [root@k8s-master secret]# kubectl describe secret mysecret### 查看描述信息 Name:mysecret Namespace:default Labels: Annotations: Type:OpaqueData =https://www.it610.com/article/=== password:12 bytes username:5 bytes

将Secret挂载到Volume中 yaml文件
[root@k8s-master secret]# pwd /root/k8s_practice/secret [root@k8s-master secret]# cat pod_secret_volume.yaml apiVersion: v1 kind: Pod metadata: name: pod-secret-volume spec: containers: - name: myapp image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1 volumeMounts: - name: secret-volume mountPath: /etc/secret readOnly: true volumes: - name: secret-volume secret: secretName: mysecret

启动pod并查看状态
[root@k8s-master secret]# kubectl apply -f pod_secret_volume.yaml pod/pod-secret-volume created [root@k8s-master secret]# [root@k8s-master secret]# kubectl get pod -o wide NAMEREADYSTATUSRESTARTSAGEIPNODENOMINATED NODEREADINESS GATES pod-secret-volume1/1Running016s10.244.2.159k8s-node02

查看secret信息
[root@k8s-master secret]# kubectl exec -it pod-secret-volume -- /bin/sh / # ls /etc/secret passwordusername / # / # cat /etc/secret/username admin/ # / # / # cat /etc/secret/password 1f2d1e2e67df/ #

由上可见,在pod中的secret信息实际已经被解密。
将Secret导入到环境变量中 yaml文件
[root@k8s-master secret]# pwd /root/k8s_practice/secret [root@k8s-master secret]# cat pod_secret_env.yaml apiVersion: v1 kind: Pod metadata: name: pod-secret-env spec: containers: - name: myapp image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1 env: - name: SECRET_USERNAME valueFrom: secretKeyRef: name: mysecret key: username - name: SECRET_PASSWORD valueFrom: secretKeyRef: name: mysecret key: password restartPolicy: Never

启动pod并查看状态
[root@k8s-master secret]# kubectl apply -f pod_secret_env.yaml pod/pod-secret-env created [root@k8s-master secret]# [root@k8s-master secret]# kubectl get pod -o wide NAMEREADYSTATUSRESTARTSAGEIPNODENOMINATED NODEREADINESS GATES pod-secret-env1/1Running06s10.244.2.160k8s-node02

查看secret信息
[root@k8s-master secret]# kubectl exec -it pod-secret-env -- /bin/sh / # env ……………… HOME=/root SECRET_PASSWORD=1f2d1e2e67df### secret信息 MYAPP_SVC_PORT_80_TCP=tcp://10.98.57.156:80 TERM=xterm NGINX_VERSION=1.12.2 KUBERNETES_PORT_443_TCP_ADDR=10.96.0.1 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin KUBERNETES_PORT_443_TCP_PORT=443 KUBERNETES_PORT_443_TCP_PROTO=tcp MYAPP_SVC_SERVICE_HOST=10.98.57.156 SECRET_USERNAME=admin### secret信息 KUBERNETES_PORT_443_TCP=tcp://10.96.0.1:443 ………………

由上可见,在pod中的secret信息实际已经被解密。
docker-registry Secret harbor镜像仓库 首先使用harbor搭建镜像仓库,搭建部署过程参考:「Harbor企业级私有Docker镜像仓库部署」
harbor部分配置文件信息
[root@k8s-master harbor]# pwd /root/App/harbor [root@k8s-master harbor]# vim harbor.yml # Configuration file of Harbor hostname: 172.16.1.110# http related config http: # port for http, default is 80. If https enabled, this port will redirect to https port port: 5000# https related config https: # https port for harbor, default is 443 port: 443 # The path of cert and key files for nginx certificate: /etc/harbor/cert/httpd.crt private_key: /etc/harbor/cert/httpd.key harbor_admin_password: Harbor12345

启动harbor后客户端http设置 集群所有机器都要操作
[root@k8s-master ~]# vim /etc/docker/daemon.json { "exec-opts": ["native.cgroupdriver=systemd"], "log-driver": "json-file", "log-opts": { "max-size": "100m" }, "insecure-registries": ["172.16.1.110:5000"] } [root@k8s-master ~]# [root@k8s-master ~]# systemctl restart docker# 重启docker服务

添加了 “insecure-registries”: [“172.16.1.110:5000”] 这行,其中172.16.1.110为内网IP地址。该文件必须符合 json 规范,否则 Docker 将不能启动。
如果在Harbor所在的机器重启了docker服务,记得要重新启动Harbor。
创建「私有」仓库 kubernetes|Kubernetes K8S之存储Secret详解
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镜像上传
docker pull registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1 docker tag registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1 172.16.1.110:5000/k8s-secret/myapp:v1 # 登录 docker login 172.16.1.110:5000 -u admin -p Harbor12345 # 上传 docker push 172.16.1.110:5000/k8s-secret/myapp:v1

kubernetes|Kubernetes K8S之存储Secret详解
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退出登录 之后在操作机上退出harbor登录,便于后面演示
### 退出harbor登录 [root@k8s-node02 ~]# docker logout 172.16.1.110:5000 Removing login credentials for 172.16.1.110:5000 ### 拉取失败,需要先登录。表明完成准备工作 [root@k8s-master secret]# docker pull 172.16.1.110:5000/k8s-secret/myapp:v1 Error response from daemon: pull access denied for 172.16.1.110:5000/k8s-secret/myapp, repository does not exist or may require 'docker login': denied: requested access to the resource is denied

pod直接下载镜像 在yaml文件中指定image后,直接启动pod
[root@k8s-master secret]# pwd /root/k8s_practice/secret [root@k8s-master secret]# cat pod_secret_registry.yaml apiVersion: v1 kind: Pod metadata: name: pod-secret-registry spec: containers: - name: myapp image: 172.16.1.110:5000/k8s-secret/myapp:v1

启动pod并查看状态
[root@k8s-master secret]# kubectl apply -f pod_secret_registry.yaml pod/pod-secret-registry created [root@k8s-master secret]# [root@k8s-master secret]# kubectl get pod -o wide### 可见镜像下载失败 NAMEREADYSTATUSRESTARTSAGEIPNODENOMINATED NODEREADINESS GATES pod-secret-registry0/1ImagePullBackOff07s10.244.2.161k8s-node02 [root@k8s-master secret]# [root@k8s-master secret]# kubectl describe pod pod-secret-registry### 查看pod详情 Name:pod-secret-registry Namespace:default Priority:0 Node:k8s-node02/172.16.1.112 Start Time:Mon, 08 Jun 2020 23:59:07 +0800 Labels: Annotations:kubectl.kubernetes.io/last-applied-configuration: {"apiVersion":"v1","kind":"Pod","metadata":{"annotations":{},"name":"pod-secret-registry","namespace":"default"},"spec":{"containers":[{"i... Status:Pending IP:10.244.2.161 IPs: IP:10.244.2.161 Containers: myapp: Container ID: Image:172.16.1.110:5000/k8s-secret/myapp:v1 Image ID: ……………… Events: TypeReasonAgeFromMessage ------------------------- NormalScheduled23sdefault-schedulerSuccessfully assigned default/pod-secret-registry to k8s-node02 NormalBackOff19s (x2 over 20s)kubelet, k8s-node02Back-off pulling image "172.16.1.110:5000/k8s-secret/myapp:v1" WarningFailed19s (x2 over 20s)kubelet, k8s-node02Error: ImagePullBackOff NormalPulling9s (x2 over 21s)kubelet, k8s-node02Pulling image "172.16.1.110:5000/k8s-secret/myapp:v1" WarningFailed9s (x2 over 21s)kubelet, k8s-node02Failed to pull image "172.16.1.110:5000/k8s-secret/myapp:v1": rpc error: code = Unknown desc = Error response from daemon: pull access denied for 172.16.1.110:5000/k8s-secret/myapp, repository does not exist or may require 'docker login': denied: requested access to the resource is denied WarningFailed9s (x2 over 21s)kubelet, k8s-node02Error: ErrImagePull [root@k8s-master secret]# [root@k8s-master secret]# kubectl delete -f pod_secret_registry.yaml

可见拉取私有镜像失败。
pod通过Secret下载镜像 通过命令行创建Secret,并查看其描述信息
[root@k8s-master secret]# kubectl create secret docker-registry myregistrysecret --docker-server='172.16.1.110:5000' --docker-username='admin' --docker-password='Harbor12345' secret/myregistrysecret created [root@k8s-master secret]# [root@k8s-master secret]# kubectl get secret NAMETYPEDATAAGE basic-authOpaque12d14h default-token-v48g4kubernetes.io/service-account-token327d myregistrysecretkubernetes.io/dockerconfigjson18s# 刚刚创建的 mysecretOpaque2118m tls-secretkubernetes.io/tls23d4h [root@k8s-master secret]# [root@k8s-master secret]# kubectl get secret myregistrysecret -o yaml### 查看详细信息 apiVersion: v1 data: .dockerconfigjson: eyJhdXRocyI6eyIxMC4wLjAuMTEwOjUwMDAiOnsidXNlcm5hbWUiOiJhZG1pbiIsInBhc3N3b3JkIjoiSGFyYm9yMTIzNDUiLCJhdXRoIjoiWVdSdGFXNDZTR0Z5WW05eU1USXpORFU9In19fQ== kind: Secret metadata: creationTimestamp: "2020-06-08T16:07:32Z" name: myregistrysecret namespace: default resourceVersion: "1004582" selfLink: /api/v1/namespaces/default/secrets/myregistrysecret uid: b95f4386-64bc-4ba3-b43a-08afb1c1eb9d type: kubernetes.io/dockerconfigjson [root@k8s-master secret]# [root@k8s-master secret]# kubectl describe secret myregistrysecret### 查看描述信息 Name:myregistrysecret Namespace:default Labels: Annotations:Type:kubernetes.io/dockerconfigjsonData =https://www.it610.com/article/=== .dockerconfigjson:109 bytes

修改之前的yaml文件
[root@k8s-master secret]# cat pod_secret_registry.yaml apiVersion: v1 kind: Pod metadata: name: pod-secret-registry spec: containers: - name: myapp image: 172.16.1.110:5000/k8s-secret/myapp:v1 imagePullSecrets: - name: myregistrysecret

启动pod并查看状态
[root@k8s-master secret]# kubectl apply -f pod_secret_registry.yaml pod/pod-secret-registry created [root@k8s-master secret]# [root@k8s-master secret]# kubectl get pod -o wide NAMEREADYSTATUSRESTARTSAGEIPNODENOMINATED NODEREADINESS GATES pod-secret-registry1/1Running08s10.244.2.162k8s-node02 [root@k8s-master secret]# [root@k8s-master secret]# kubectl describe pod pod-secret-registry Name:pod-secret-registry Namespace:default Priority:0 Node:k8s-node02/172.16.1.112 Start Time:Tue, 09 Jun 2020 00:22:40 +0800 Labels: Annotations:kubectl.kubernetes.io/last-applied-configuration: {"apiVersion":"v1","kind":"Pod","metadata":{"annotations":{},"name":"pod-secret-registry","namespace":"default"},"spec":{"containers":[{"i... Status:Running IP:10.244.2.162 IPs: IP:10.244.2.162 Containers: myapp: Container ID:docker://ef4d42f1f1616a44c2a6c0a5a71333b27f46dfe76eb392962813a28d69150c00 Image:172.16.1.110:5000/k8s-secret/myapp:v1 Image ID:docker-pullable://172.16.1.110:5000/k8s-secret/myapp@sha256:9eeca44ba2d410e54fccc54cbe9c021802aa8b9836a0bcf3d3229354e4c8870e Port: Host Port: State:Running Started:Tue, 09 Jun 2020 00:22:41 +0800 Ready:True Restart Count:0 Environment: Mounts: /var/run/secrets/kubernetes.io/serviceaccount from default-token-v48g4 (ro) Conditions: TypeStatus InitializedTrue ReadyTrue ContainersReadyTrue PodScheduledTrue Volumes: default-token-v48g4: Type:Secret (a volume populated by a Secret) SecretName:default-token-v48g4 Optional:false QoS Class:BestEffort Node-Selectors: Tolerations:node.kubernetes.io/not-ready:NoExecute for 300s node.kubernetes.io/unreachable:NoExecute for 300s Events: TypeReasonAgeFromMessage ------------------------- NormalScheduled22sdefault-schedulerSuccessfully assigned default/pod-secret-registry to k8s-node02 NormalPulling22skubelet, k8s-node02Pulling image "172.16.1.110:5000/k8s-secret/myapp:v1" NormalPulled22skubelet, k8s-node02Successfully pulled image "172.16.1.110:5000/k8s-secret/myapp:v1" NormalCreated22skubelet, k8s-node02Created container myapp NormalStarted21skubelet, k8s-node02Started container myapp

由上可见,通过secret认证后pod拉取私有镜像是可以的。
相关阅读 1、Harbor企业级私有Docker镜像仓库部署
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