Kubernetes Secret 资源对象使用方法：

1. 创建 Secret

   apiVersion: v1
   kind: Secret
   metadata:
     name: my-secret
     namespace: default
   data:
     username: YWRtaW4=
     password: MWYyZDFlMmU2NTIxODRhNjc2YWUxZGM3YmQzZDgxOTM=
   

2. 引用 Secret

   apiVersion: v1
   kind: Pod
   metadata:
     name: my-pod
     namespace: default
   spec:
     containers:
     - name: my-container
       image: nginx
       env:
       - name: MY_USERNAME
         valueFrom:
           secretKeyRef:
             name: my-secret
             key: username
       - name: MY_PASSWORD
         valueFrom:
           secretKeyRef:
             name: my-secret
             key: password
   

3. 挂载 Secret

   apiVersion: v1
   kind: Pod
   metadata:
     name: my-pod
     namespace: default
   spec:
     containers:
     - name: my-container
       image: nginx
       volumeMounts:
       - name: my-secret
         mountPath: /etc/secrets
     volumes:
     - name: my-secret
       secret:
         secretName: my-secret
   

4. 使用环境变量

   apiVersion: v1
   kind: Pod
   metadata:
     name: my-pod
     namespace: default
   spec:
     containers:
     - name: my-container
       image: nginx
       envFrom:
       - secretRef:
           name: my-secret
   

5. 使用 ConfigMap

   apiVersion: v1
   kind: ConfigMap
   metadata:
     name: my-configmap
     namespace: default
   data:
     username: admin
     password: password
   

   apiVersion: v1
   kind: Pod
   metadata:
     name: my-pod
     namespace: default
   spec:
     containers:
     - name: my-container
       image: nginx
       envFrom:
       - configMapRef:
           name: my-configmap
   

6. 使用 Secrets 插件

   apiVersion: v1
   kind: Pod
   metadata:
     name: my-pod
     namespace: default
   spec:
     containers:
     - name: my-container
       image: nginx
       volumeMounts:
       - name: my-secret
         mountPath: /etc/secrets
     volumes:
     - name: my-secret
       projected:
         sources:
         - secret:
             name: my-secret
             items:
             - key: username
               path: my-username
             - key: password
               path: my-password
   

7. 使用 init 容器

   apiVersion: v1
   kind: Pod
   metadata:
     name: my-pod
     namespace: default
   spec:
     initContainers:
     - name: init-secret
       image: busybox
       command: ["cp", "/secret/username", "/etc/app/username"]
     containers:
     - name: my-container
       image: my-app
       env:
       - name: MY_USERNAME
         value: /etc/app/username
     volumes:
     - name: my-secret
       secret:
         secretName: my-secret
   

8. 使用 Downward API

   apiVersion: v1
   kind: Pod
   metadata:
     name: my-pod
     namespace: default
   spec:
     containers:
     - name: my-container
       image: nginx
       env:
       - name: MY_POD_NAME
         valueFrom:
           fieldRef:
             fieldPath: metadata.name
       - name: MY_POD_NAMESPACE
         valueFrom:
           fieldRef:
             fieldPath: metadata.namespace