6.5.3.2. 使用卷插件消耗容器资源

在创建 pod 时,您可以利用卷插件来使用 Downward API 注入有关计算资源请求和限制的信息。

流程

使用卷插件:

  1. 在创建 pod 配置时,使用 spec.volumes.downwardAPI.items 字段来描述与 spec.resources 字段对应的所需资源:

    ....
    spec:
      containers:
        - name: client-container
          image: gcr.io/google_containers/busybox:1.24
          command: ["sh", "-c", "while true; do echo; if [[ -e /etc/cpu_limit ]]; then cat /etc/cpu_limit; fi; if [[ -e /etc/cpu_request ]]; then cat /etc/cpu_request; fi; if [[ -e /etc/mem_limit ]]; then cat /etc/mem_limit; fi; if [[ -e /etc/mem_request ]]; then cat /etc/mem_request; fi; sleep 5; done"]
          resources:
            requests:
              memory: "32Mi"
              cpu: "125m"
            limits:
              memory: "64Mi"
              cpu: "250m"
          volumeMounts:
            - name: podinfo
              mountPath: /etc
              readOnly: false
      volumes:
        - name: podinfo
          downwardAPI:
            items:
              - path: "cpu_limit"
                resourceFieldRef:
                  containerName: client-container
                  resource: limits.cpu
              - path: "cpu_request"
                resourceFieldRef:
                  containerName: client-container
                  resource: requests.cpu
              - path: "mem_limit"
                resourceFieldRef:
                  containerName: client-container
                  resource: limits.memory
              - path: "mem_request"
                resourceFieldRef:
                  containerName: client-container
                  resource: requests.memory
    ....

    如果容器配置中没有包含资源限制,Downward API 会默认使用节点的 CPU 和内存可分配量。

  2. volume-pod.yaml 文件创建 pod:

    $ oc create -f volume-pod.yaml