apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/util/ConfigFileUtils.java/ConfigFileUtils/genClusterInfoPath
class ConfigFileUtils:  public static String genClusterInfoPath(App app, Env env, ClusterDTO cluster) {
    return String.join(File.separator, app.getOwnerName(), app.getAppId(), env.getName(),
                       cluster.getName() + CLUSTER_METADATA_FILE_SUFFIX);
  }