kubeasz/roles/docker/files/daemon.json

{
  "registry-mirrors": ["https://registry.docker-cn.com"], 
  "max-concurrent-downloads": 10,
  "log-driver": "json-file",
  "log-level": "warn",
  "log-opts": {
    "max-size": "10m",
    "max-file": "3"
    }
}