apollo-portal/src/main/java/com/ctrip/framework/apollo/openapi/server/service/ServerAppOpenApiService.java/ServerAppOpenApiService/getEnvClusterInfo
class ServerAppOpenApiService:  @Override
  public List<OpenEnvClusterDTO> getEnvClusterInfo(String appId) {
    List<OpenEnvClusterDTO> envClusters = new LinkedList<>();

    List<Env> envs = portalSettings.getActiveEnvs();
    for (Env env : envs) {
      OpenEnvClusterDTO envCluster = new OpenEnvClusterDTO();

      envCluster.setEnv(env.getName());
      List<ClusterDTO> clusterDTOs = clusterService.findClusters(env, appId);
      envCluster.setClusters(BeanUtils.toPropertySet("name", clusterDTOs));

      envClusters.add(envCluster);
    }

    return envClusters;
  }