42.5. 从 Pod 中查找内存请求和限制

希望从 pod 中动态发现内存请求和限制的应用程序应该使用 Downward API。下列代码片段演示了如何完成此操作。

apiVersion: v1
kind: Pod
metadata:
  name: test
spec:
  containers:
  - name: test
    image: fedora:latest
    command:
    - sleep
    - "3600"
    env:
    - name: MEMORY_REQUEST
      valueFrom:
        resourceFieldRef:
          containerName: test
          resource: requests.memory
    - name: MEMORY_LIMIT
      valueFrom:
        resourceFieldRef:
          containerName: test
          resource: limits.memory
    resources:
      requests:
        memory: 384Mi
      limits:
        memory: 512Mi

# oc rsh test
$ env | grep MEMORY | sort
MEMORY_LIMIT=536870912
MEMORY_REQUEST=402653184

内存限制值也可由 /sys/fs/cgroup/memory/memory.limit_in_bytes 文件从容器内部读取。