{
  "type": "bootstrap",
  "id": "bootstrap1",
  "domain_id": "userid1",
  "config": {
    "id": "factory1",
    "backend_type": "localfs",
    "backend_config": {
      "dir": "/tmp/nydus"
    },
    "cache_type": "fscache",
    "cache_config": {
      "work_dir": "/tmp/nydus"
    },
    "metadata_file": "/tmp/nydus/bootstrap1"
  }
}