Secret

Kubernetes 提供了secret来处理敏感数据,比如密码、token和秘钥，相比于直接将敏感数据配置在Pod定义或者镜像中,Secret提供了更加安全的机制(Base64加密),防止数据泄露.Sercret 的创建是独立于Pod,以数据卷的形式挂载到Pod中,Secret的数据将以文件的形式保存,容器通过读取文件可以获取需要的数据.
目前Secret的类型有有以下三种:
1、Opaque(default): 任意字符串
2、kubernetes.io/service-account-token: 作用于ServiceAccount
3、kubernetes.io/dockercfg: 作用于Docker registry，用户下载docker镜像认证使用

Opaque Secret

Opaque 类型的数据是一个map类型,要求value是base64编码格式:

# echo -n "admin" | base64
YWRtaW4=
# echo -n "1f2d1e2e67df" | base64
MWYyZDFlMmU2N2Rm

#cat secrets.yml
apiVersion: v1
kind: Secret
metadata:
  name: mysecret
type: Opaque
data:
  password: MWYyZDFlMmU2N2Rm
  username: YWRtaW4=

#kubectl create -f secrets.yml -n default
secret/mysecret created

验证创建的Secrets

12345.png

secret 引用方式

1、Volume方式
2、环境变量方式

Secret挂载到Volume中

apiVersion: v1
kind: Pod
metadata:
  labels:
    name: db
  name: db
spec:
  volumes:
  - name: secrets
    secret:
      secretName: mysecret
  containers:
  - image: gcr.io/my_project_id/pg:v1
    name: db
    volumeMounts:
    - name: secrets
      mountPath: "/apps/conf/secrets"
      readOnly: true
    ports:
    - name: cp
      containerPort: 5432
      hostPort: 5432

Secret导出到环境变量中

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: wordpress-deployment
spec:
  replicas: 2
  strategy:
      type: RollingUpdate
  template:
    metadata:
      labels:
        app: wordpress
        visualize: "true"
    spec:
      containers:
      - name: "wordpress"
        image: "wordpress"
        ports:
        - containerPort: 80
        env:
        - name: WORDPRESS_DB_USER
          valueFrom:
            secretKeyRef:
              name: mysecret
              key: username
        - name: WORDPRESS_DB_PASSWORD
          valueFrom:
            secretKeyRef:
              name: mysecret
              key: password

kubernetes.io/dockerconfigjson

直接用kubectl命令来创建用于docker registry认证的secret：

# kubectl create secret docker-registry myregistrykey --docker-server=DOCKER_REGISTRY_SERVER --docker-username=DOCKER_USER --docker-password=DOCKER_PASSWORD --docker-email=DOCKER_EMAIL
secret "myregistrykey" created.

也可以直接读取~/.docker/config.json的内容来创建

# cat ~/.docker/config.json | base64
# cat > myregistrykey.yaml <<EOF
apiVersion: v1
kind: Secret
metadata:
  name: myregistrykey
data:
  .dockerconfigjson: UmVhbGx5IHJlYWxseSByZWVlZWVlZWVlZWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWxsbGxsbGxsbGxsbGxsbGxsbGxsbGxsbGxsbGxsbGx5eXl5eXl5eXl5eXl5eXl5eXl5eSBsbGxsbGxsbGxsbGxsbG9vb29vb29vb29vb29vb29vb29vb29vb29vb25ubm5ubm5ubm5ubm5ubm5ubm5ubm5ubmdnZ2dnZ2dnZ2dnZ2dnZ2dnZ2cgYXV0aCBrZXlzCg==
type: kubernetes.io/dockerconfigjson
EOF
$ kubectl create -f myregistrykey.yaml

在创建Pod的时候，通过imagePullSecrets来引用刚创建的myregistrykey:

apiVersion: v1
kind: Pod
metadata:
  name: foo
spec:
  containers:
    - name: foo
      image: janedoe/awesomeapp:v1
  imagePullSecrets:
    - name: myregistrykey

Service Account

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

$ kubectl run nginx --image nginx
deployment "nginx" created
$ kubectl get pods
NAME                     READY     STATUS    RESTARTS   AGE
nginx-3137573019-md1u2   1/1       Running   0          13s
$ kubectl exec nginx-3137573019-md1u2 ls /run/secrets/kubernetes.io/serviceaccount
ca.crt
namespace
token

Kubernetes 数据持久化之Secret