kubernetes 通过环境变量暴露POD的信息给容器

阳光穿透心脏的1/2处 2022-05-25 04:05 148阅读 0赞

有时候，容器需要获取pod的信息时，就可以通过设置环境保护来实现  
例子  
1.使用POD 的字段的值作为环境变量的值

apiVersion: v1
    kind: Pod
    metadata:
      name: dapi-envars-fieldref
    spec:
      containers:
        - name: test-container       image: k8s.gcr.io/busybox
          command: [ "sh", "-c"]
          args:
          - while true; do           echo -en '\n';
              printenv MY_NODE_NAME MY_POD_NAME MY_POD_NAMESPACE;//对应下面的环境变量的值
              printenv MY_POD_IP MY_POD_SERVICE_ACCOUNT;
              sleep 10;
            done;
          env:
            - name: MY_NODE_NAME           valueFrom:
                fieldRef:
                  fieldPath: spec.nodeName
            - name: MY_POD_NAME           valueFrom:
                fieldRef:
                  fieldPath: metadata.name
            - name: MY_POD_NAMESPACE           valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
            - name: MY_POD_IP           valueFrom:
                fieldRef:
                  fieldPath: status.podIP
            - name: MY_POD_SERVICE_ACCOUNT           valueFrom:
                fieldRef:
                  fieldPath: spec.serviceAccountName
      restartPolicy: Never

2.使用容器的字段的值作为环境变量的值  
例子

apiVersion: v1
    kind: Pod
    metadata:
      name: dapi-envars-resourcefieldref
    spec:
      containers:
        - name: test-container
          image: k8s.gcr.io/busybox:1.24
          command: [ "sh", "-c"]
          args:
          - while true; do
              echo -en '\n';
              printenv MY_CPU_REQUEST MY_CPU_LIMIT;
              printenv MY_MEM_REQUEST MY_MEM_LIMIT;
              sleep 10;
            done;
          resources:
            requests:
              memory: "32Mi"
              cpu: "125m"
            limits:
              memory: "64Mi"
              cpu: "250m"
          env:
            - name: MY_CPU_REQUEST
              valueFrom:
                resourceFieldRef:
                  containerName: test-container
                  resource: requests.cpu
            - name: MY_CPU_LIMIT
              valueFrom:
                resourceFieldRef:
                  containerName: test-container
                  resource: limits.cpu
            - name: MY_MEM_REQUEST
              valueFrom:
                resourceFieldRef:
                  containerName: test-container
                  resource: requests.memory
            - name: MY_MEM_LIMIT
              valueFrom:
                resourceFieldRef:
                  containerName: test-container
                  resource: limits.memory
      restartPolicy: Never

参考：  
[environment-variable-expose-pod-information][]

[environment-variable-expose-pod-information]: https://kubernetes.io/docs/tasks/inject-data-application/environment-variable-expose-pod-information/