Kubernetes m6S之存储点Secret精解
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
1 [root@k8s-master ~]# kubectl get pod -A | grep'kube-proxy'2 kube-system kube-proxy-6bfh7 1/1 Running 12 7d3h
3 kube-system kube-proxy-6vfkf 1/1 Running 11 7d3h
4 kube-system kube-proxy-bvl9n 1/1 Running 11 7d3h
5 [root@k8s-master ~]#
6 [root@k8s-master ~]# kubectl exec -it -n kube-system kube-proxy-6bfh7 -- /bin/sh
7 # ls -l /run/secrets/kubernetes.io/serviceaccount
8 total 0
9 lrwxrwxrwx 1 root root 13 Jun 813:39 ca.crt -> ..data/ca.crt
10 lrwxrwxrwx 1 root root 16 Jun 813:39 namespace -> ..data/namespace
11 lrwxrwxrwx 1 root root 12 Jun 813:39 token -> ..data/token
Opaque Secret
创建secret
手动加密,基于base64加密
1 [root@k8s-master ~]# echo -n 'admin' | base642 YWRtaW4=3 [root@k8s-master ~]# echo -n '1f2d1e2e67df' | base64
4 MWYyZDFlMmU2N2Rm
yaml文件
1 [root@k8s-master secret]# pwd2 /root/k8s_practice/secret
3 [root@k8s-master secret]# cat secret.yaml
4apiVersion: v1
5kind: Secret
6metadata:
7 name: mysecret
8type: Opaque
9data:
10 username: YWRtaW4=
11 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
1 [root@k8s-master secret]# kubectl apply -f secret.yaml 2 secret/mysecret created 3 [root@k8s-master secret]# 4 [root@k8s-master secret]# kubectl get secret ### 查看默认名称空间的secret简要信息 5NAME TYPE DATA AGE 6 basic-auth Opaque 1 2d12h 7 default-token-v48g4 kubernetes.io/service-account-token 3 27d 8 mysecret Opaque 2 23s ### 可见已创建 9 tls-secret kubernetes.io/tls 2 3d2h10 [root@k8s-master secret]#11 [root@k8s-master secret]# kubectl get secret mysecret -o yaml ### 查看mysecret详细信息12apiVersion: v113data:14 password: MWYyZDFlMmU2N2Rm15 username: YWRtaW4=16kind: Secret
17metadata:
18 annotations:
19 kubectl.kubernetes.io/last-applied-configuration: |
20 {"apiVersion":"v1","data":{"password":"MWYyZDFlMmU2N2Rm","username":"YWRtaW4="},"kind":"Secret","metadata":{"annotations":{},"name":"mysecret","namespace":"default"},"type":"Opaque"}
21 creationTimestamp: "2020-06-08T14:08:59Z"
22 name: mysecret
23 namespace: default
24 resourceVersion: "987419"
25 selfLink: /api/v1/namespaces/default/secrets/mysecret
26 uid: 27b58929-71c4-495b-99a5-0d411910a529
27type: Opaque
28 [root@k8s-master secret]#
29 [root@k8s-master secret]# kubectl describe secret mysecret ### 查看描述信息
30Name: mysecret
31Namespace: default
32 Labels: <none>
33Annotations:
34Type: Opaque
35
36Data
37 ====
38 password: 12 bytes
39 username: 5 bytes
将Secret挂载到Volume中
yaml文件
1 [root@k8s-master secret]# pwd2 /root/k8s_practice/secret
3 [root@k8s-master secret]# cat pod_secret_volume.yaml
4apiVersion: v1
5kind: Pod
6metadata:
7 name: pod-secret-volume
8spec:
9 containers:
10 - name: myapp
11 image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1
12 volumeMounts:
13 - name: secret-volume
14 mountPath: /etc/secret
15 readOnly: true
16 volumes:
17 - name: secret-volume
18 secret:
19 secretName: mysecret
启动pod并查看状态
1 [root@k8s-master secret]# kubectl apply -f pod_secret_volume.yaml2 pod/pod-secret-volume created3 [root@k8s-master secret]#4 [root@k8s-master secret]# kubectl get pod -o wide5NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES6 pod-secret-volume 1/1 Running 0 16s 10.244.2.159 k8s-node02 <none> <none>
查看secret信息
1 [root@k8s-master secret]# kubectl exec -it pod-secret-volume -- /bin/sh2 / # ls /etc/secret
3password username
4 / #
5 / # cat /etc/secret/username
6 admin/ #
7 / #
8 / # cat /etc/secret/password
9 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
1 [root@k8s-master secret]# pwd2 /root/k8s_practice/secret
3 [root@k8s-master secret]# cat pod_secret_env.yaml
4apiVersion: v1
5kind: Pod
6metadata:
7 name: pod-secret-env
8spec:
9 containers:
10 - name: myapp
11 image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1
12env:
13 - name: SECRET_USERNAME
14 valueFrom:
15 secretKeyRef:
16 name: mysecret
17 key: username
18 - name: SECRET_PASSWORD
19 valueFrom:
20 secretKeyRef:
21 name: mysecret
22 key: password
23 restartPolicy: Never
启动pod并查看状态
1 [root@k8s-master secret]# kubectl apply -f pod_secret_env.yaml2 pod/pod-secret-env created3 [root@k8s-master secret]#4 [root@k8s-master secret]# kubectl get pod -o wide5NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES6 pod-secret-env1/1 Running 0 6s 10.244.2.160 k8s-node02 <none> <none>
查看secret信息
1 [root@k8s-master secret]# kubectl exec -it pod-secret-env -- /bin/sh2 / # env
3………………
4 HOME=/root
5 SECRET_PASSWORD=1f2d1e2e67df ### secret信息
6 MYAPP_SVC_PORT_80_TCP=tcp://10.98.57.156:80
7 TERM=xterm
8 NGINX_VERSION=1.12.2
9 KUBERNETES_PORT_443_TCP_ADDR=10.96.0.1
10 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
11 KUBERNETES_PORT_443_TCP_PORT=443
12 KUBERNETES_PORT_443_TCP_PROTO=tcp
13 MYAPP_SVC_SERVICE_HOST=10.98.57.156
14 SECRET_USERNAME=admin ### secret信息
15 KUBERNETES_PORT_443_TCP=tcp://10.96.0.1:443
16 ………………
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」
1 [root@k8s-master harbor]# pwd2 /root/App/harbor
3 [root@k8s-master harbor]# vim harbor.yml
4 # Configuration file of Harbor
5hostname: 172.16.1.110
6
7# http related config
8http:
9 # port for http, default is 80. If https enabled, this port will redirect to https port
10 port: 5000
11
12# https related config
13https:
14 # https port for harbor, default is 443
15 port: 443
16 # The path of cert and key files for nginx
17 certificate: /etc/harbor/cert/httpd.crt
18 private_key: /etc/harbor/cert/httpd.key
19 harbor_admin_password: Harbor12345
集群所有机器都要操作
1 [root@k8s-master ~]# vim /etc/docker/daemon.json 2{ 3"exec-opts": ["native.cgroupdriver=systemd"], 4"log-driver": "json-file", 5"log-opts": { 6"max-size": "100m"7 },
8"insecure-registries": ["172.16.1.110:5000"]
9}
10 [root@k8s-master ~]#
11 [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。
1 docker pull registry.cn-beijing.aliyuncs.com/google_registry/myapp:v12 docker tag registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1 172.16.1.110:5000/k8s-secret/myapp:v13# 登录4 docker login172.16.1.110:5000 -u admin -p Harbor123455# 上传6 docker push 172.16.1.110:5000/k8s-secret/myapp:v1
之后在操作机上退出harbor登录,便于后面演示
1### 退出harbor登录2 [root@k8s-node02 ~]# docker logout 172.16.1.110:50003 Removing login credentials for172.16.1.110:5000
4### 拉取失败,需要先登录。表明完成准备工作
5 [root@k8s-master secret]# docker pull 172.16.1.110:5000/k8s-secret/myapp:v1
6 Error response from daemon: pull access denied for172.16.1.110:5000/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
1 [root@k8s-master secret]# pwd2 /root/k8s_practice/secret
3 [root@k8s-master secret]# cat pod_secret_registry.yaml
4apiVersion: v1
5kind: Pod
6metadata:
7 name: pod-secret-registry
8spec:
9 containers:
10 - name: myapp
11 image: 172.16.1.110:5000/k8s-secret/myapp:v1
启动pod并查看状态
1 [root@k8s-master secret]# kubectl apply -f pod_secret_registry.yaml 2 pod/pod-secret-registry created 3 [root@k8s-master secret]# 4 [root@k8s-master secret]# kubectl get pod -o wide ### 可见镜像下载失败 5NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES 6 pod-secret-registry 0/1 ImagePullBackOff 0 7s 10.244.2.161 k8s-node02 <none> <none>7 [root@k8s-master secret]#
8 [root@k8s-master secret]# kubectl describe pod pod-secret-registry ### 查看pod详情
9 Name: pod-secret-registry
10Namespace: default
11 Priority: 0
12 Node: k8s-node02/172.16.1.112
13 Start Time: Mon, 08 Jun 202023:59:07 +0800
14 Labels: <none>
15 Annotations: kubectl.kubernetes.io/last-applied-configuration:
16 {"apiVersion":"v1","kind":"Pod","metadata":{"annotations":{},"name":"pod-secret-registry","namespace":"default"},"spec":{"containers":[{"i...
17Status: Pending
18 IP: 10.244.2.161
19IPs:
20 IP: 10.244.2.161
21Containers:
22 myapp:
23 Container ID:
24 Image: 172.16.1.110:5000/k8s-secret/myapp:v1
25 Image ID:
26………………
27Events:
28 Type Reason Age From Message
29 ---- ------ ---- ---- -------
30 Normal Scheduled 23s default-scheduler Successfully assigned default/pod-secret-registry to k8s-node02
31 Normal BackOff 19s (x2 over 20s) kubelet, k8s-node02 Back-off pulling image "172.16.1.110:5000/k8s-secret/myapp:v1"
32 Warning Failed 19s (x2 over 20s) kubelet, k8s-node02 Error: ImagePullBackOff
33 Normal Pulling 9s (x2 over 21s) kubelet, k8s-node02 Pulling image "172.16.1.110:5000/k8s-secret/myapp:v1"
34 Warning Failed 9s (x2 over 21s) kubelet, k8s-node02 Failed to pull image "172.16.1.110:5000/k8s-secret/myapp:v1": rpc error: code = Unknown desc = Error response from daemon: pull access denied for172.16.1.110:5000/k8s-secret/myapp, repository does not exist or may require 'docker login': denied: requested access to the resource is denied
35 Warning Failed 9s (x2 over 21s) kubelet, k8s-node02 Error: ErrImagePull
36 [root@k8s-master secret]#
37 [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
1 [root@k8s-master secret]# kubectl create secret docker-registry myregistrysecret --docker-server='172.16.1.110:5000' --docker-username='admin' --docker-password='Harbor12345'2 secret/myregistrysecret created
3 [root@k8s-master secret]#
4 [root@k8s-master secret]# kubectl get secret
5NAME TYPE DATA AGE
6 basic-auth Opaque 1 2d14h
7 default-token-v48g4 kubernetes.io/service-account-token 3 27d
8 myregistrysecret kubernetes.io/dockerconfigjson 1 8s # 刚刚创建的
9 mysecret Opaque 2 118m
10 tls-secret kubernetes.io/tls 2 3d4h
11 [root@k8s-master secret]#
12 [root@k8s-master secret]# kubectl get secret myregistrysecret -o yaml ### 查看详细信息
13apiVersion: v1
14data:
15 .dockerconfigjson: eyJhdXRocyI6eyIxMC4wLjAuMTEwOjUwMDAiOnsidXNlcm5hbWUiOiJhZG1pbiIsInBhc3N3b3JkIjoiSGFyYm9yMTIzNDUiLCJhdXRoIjoiWVdSdGFXNDZTR0Z5WW05eU1USXpORFU9In19fQ==
16kind: Secret
17metadata:
18 creationTimestamp: "2020-06-08T16:07:32Z"
19 name: myregistrysecret
20 namespace: default
21 resourceVersion: "1004582"
22 selfLink: /api/v1/namespaces/default/secrets/myregistrysecret
23 uid: b95f4386-64bc-4ba3-b43a-08afb1c1eb9d
24 type: kubernetes.io/dockerconfigjson
25 [root@k8s-master secret]#
26 [root@k8s-master secret]# kubectl describe secret myregistrysecret ### 查看描述信息
27Name: myregistrysecret
28Namespace: default
29 Labels: <none>
30 Annotations: <none>
31
32 Type: kubernetes.io/dockerconfigjson
33
34Data
35 ====
36 .dockerconfigjson: 109 bytes
修改之前的yaml文件
1 [root@k8s-master secret]# cat pod_secret_registry.yaml 2apiVersion: v1 3kind: Pod 4metadata: 5 name: pod-secret-registry 6spec: 7 containers: 8 - name: myapp 9 image: 172.16.1.110:5000/k8s-secret/myapp:v110 imagePullSecrets:11 - name: myregistrysecret
启动pod并查看状态
1 [root@k8s-master secret]# kubectl apply -f pod_secret_registry.yaml 2 pod/pod-secret-registry created 3 [root@k8s-master secret]# 4 [root@k8s-master secret]# kubectl get pod -o wide 5NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES 6 pod-secret-registry 1/1 Running 0 8s 10.244.2.162 k8s-node02 <none> <none>7 [root@k8s-master secret]#
8 [root@k8s-master secret]# kubectl describe pod pod-secret-registry
9 Name: pod-secret-registry
10Namespace: default
11 Priority: 0
12 Node: k8s-node02/172.16.1.112
13 Start Time: Tue, 09 Jun 202000:22:40 +0800
14 Labels: <none>
15 Annotations: kubectl.kubernetes.io/last-applied-configuration:
16 {"apiVersion":"v1","kind":"Pod","metadata":{"annotations":{},"name":"pod-secret-registry","namespace":"default"},"spec":{"containers":[{"i...
17Status: Running
18 IP: 10.244.2.162
19IPs:
20 IP: 10.244.2.162
21Containers:
22 myapp:
23 Container ID: docker://ef4d42f1f1616a44c2a6c0a5a71333b27f46dfe76eb392962813a28d69150c00
24 Image: 172.16.1.110:5000/k8s-secret/myapp:v1
25 Image ID: docker-pullable://172.16.1.110:5000/k8s-secret/myapp@sha256:9eeca44ba2d410e54fccc54cbe9c021802aa8b9836a0bcf3d3229354e4c8870e
26 Port: <none>
27 Host Port: <none>
28 State: Running
29 Started: Tue, 09 Jun 202000:22:41 +0800
30 Ready: True
31 Restart Count: 0
32 Environment: <none>
33 Mounts:
34 /var/run/secrets/kubernetes.io/serviceaccount from default-token-v48g4 (ro)
35Conditions:
36 Type Status
37 Initialized True
38 Ready True
39 ContainersReady True
40 PodScheduled True
41Volumes:
42 default-token-v48g4:
43 Type: Secret (a volume populated by a Secret)
44 SecretName: default-token-v48g4
45 Optional: false
46QoS Class: BestEffort
47 Node-Selectors: <none>
48 Tolerations: node.kubernetes.io/not-ready:NoExecute for 300s
49 node.kubernetes.io/unreachable:NoExecute for 300s
50Events:
51 Type Reason Age From Message
52 ---- ------ ---- ---- -------
53 Normal Scheduled 22s default-scheduler Successfully assigned default/pod-secret-registry to k8s-node02
54 Normal Pulling 22s kubelet, k8s-node02 Pulling image "172.16.1.110:5000/k8s-secret/myapp:v1"
55 Normal Pulled 22s kubelet, k8s-node02 Successfully pulled image "172.16.1.110:5000/k8s-secret/myapp:v1"
56 Normal Created 22s kubelet, k8s-node02 Created container myapp
57 Normal Started 21s kubelet, k8s-node02 Started 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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