apollo-configservice/src/main/java/com/ctrip/framework/apollo/metaservice/service/SpringCloudInnerDiscoveryService.java/SpringCloudInnerDiscoveryService/toServiceDTO
class SpringCloudInnerDiscoveryService:    private ServiceDTO toServiceDTO(ServiceInstance instance, String appName) {
        ServiceDTO service = new ServiceDTO();
        service.setAppName(appName);
        service.setInstanceId(instance.getInstanceId());
        String homePageUrl = "http://" + instance.getHost() + ":" + instance.getPort() + "/";
        service.setHomepageUrl(homePageUrl);
        return service;
    }