kubectl explain pods.spec.containers.env.valueFrom ``` FIELDS: configMapKeyRef <Object> #configMap某个键值 Selects a key of a ConfigMap. fieldRef <Object> #某个字段，pod自身的字段，它们不是 Pod 中的容器的字段 Selects a field of the pod: supports metadata.name, metadata.namespace, metadata.labels, metadata.annotations, spec.nodeName, spec.serviceAccountName, status.hostIP, status.podIP. resourceFieldRef <Object> #资源需求和资源限制 Selects a resource of the container: only resources limits and requests (limits.cpu, limits.memory, limits.ephemeral-storage, requests.cpu, requests.memory and requests.ephemeral-storage) are currently supported. secretKeyRef <Object> Selects a key of a secret in the pod's namespace ``` **使用pod字段做为环境变量的值** ``` 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; 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_IP valueFrom: fieldRef: fieldPath: status.podIP - name: MY_POD_SERVICE_ACCOUNT valueFrom: fieldRef: fieldPath: spec.serviceAccountName restartPolicy: Never ``` ## **使用容器字段作为环境变量的值** ``` ~~~ 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_LIMIT valueFrom: resourceFieldRef: containerName: test-container resource: limits.cpu - name: MY_MEM_REQUEST valueFrom: resourceFieldRef: containerName: test-container resource: requests.memory restartPolicy: Never ```