在Pod容器内部调用api：
curl --cacert /var/run/secrets/kubernetes.io/serviceaccount/ca.crt \
--header "Authorization: Bearer $(cat /var/run/secrets/kubernetes.io/serviceaccount/token)" \
https://$KUBERNETES_SERVICE_HOST:$KUBERNETES_SERVICE_PORT/api
查询Pod命名空间的的所有pods（前提是serviceaccount有get和list pods的权限）：
curl --cacert /var/run/secrets/kubernetes.io/serviceaccount/ca.crt \
--header "Authorization: Bearer $(cat /var/run/secrets/kubernetes.io/serviceaccount/token)"
https://$KUBERNETES_SERVICE_HOST:$KUBERNETES_SERVICE_PORT/api/v1/namespaces/$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace)/pods
