# Secret Secret解決了密碼、token、密鑰等敏感數據的配置問題，而不需要把這些敏感數據暴露到鏡像或者Pod Spec中。Secret可以以Volume或者環境變量的方式使用。 Secret有三種類型： * **Service Account** ：用來訪問Kubernetes API，由Kubernetes自動創建，并且會自動掛載到Pod的`/run/secrets/kubernetes.io/serviceaccount`目錄中； * **Opaque** ：base64編碼格式的Secret，用來存儲密碼、密鑰等； * **kubernetes.io/dockerconfigjson** ：用來存儲私有docker registry的認證信息。 ## Opaque Secret Opaque類型的數據是一個map類型，要求value是base64編碼格式： ```sh $ echo -n "admin" | base64 YWRtaW4= $ echo -n "1f2d1e2e67df" | base64 MWYyZDFlMmU2N2Rm ``` secrets.yml ```yaml apiVersion: v1 kind: Secret metadata: name: mysecret type: Opaque data: password: MWYyZDFlMmU2N2Rm username: YWRtaW4= ``` 接著，就可以創建secret了：`kubectl create -f secrets.yml`。 創建好secret之后，有兩種方式來使用它： * 以Volume方式 * 以環境變量方式 ### 將Secret掛載到Volume中 ```yaml 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: "/etc/secrets" readOnly: true ports: - name: cp containerPort: 5432 hostPort: 5432 ``` ### 將Secret導出到環境變量中 ```yaml 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 可以直接用`kubectl`命令來創建用于docker registry認證的secret： ```sh $ 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. ``` 也可以直接讀取`~/.docker/config.json`的內容來創建： ```sh $ 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 ``` 在創建Pod的時候，通過`imagePullSecrets`來引用剛創建的`myregistrykey`: ```yaml apiVersion: v1 kind: Pod metadata: name: foo spec: containers: - name: foo image: janedoe/awesomeapp:v1 imagePullSecrets: - name: myregistrykey ``` ### Service Account Service Account用來訪問Kubernetes API，由Kubernetes自動創建，并且會自動掛載到Pod的`/run/secrets/kubernetes.io/serviceaccount`目錄中。 ```sh $ 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 ```