apollo-client/src/main/java/com/ctrip/framework/apollo/internals/ConfigServiceLocator.java/ConfigServiceLocator/assembleMetaServiceUrl
class ConfigServiceLocator:  private String assembleMetaServiceUrl() {
    String domainName = m_configUtil.getMetaServerDomainName();
    String appId = m_configUtil.getAppId();
    String localIp = m_configUtil.getLocalIp();

    Map<String, String> queryParams = Maps.newHashMap();
    queryParams.put("appId", queryParamEscaper.escape(appId));
    if (!Strings.isNullOrEmpty(localIp)) {
      queryParams.put("ip", queryParamEscaper.escape(localIp));
    }

    return domainName + "/services/config?" + MAP_JOINER.join(queryParams);
  }