TL; DR：当安装后脚本无法看到MySQL服务器时,composer安装失败

我正在为Symfony应用程序构建一个docker容器,在构建期间我会做这样的事情

RUN export SYMFONY_ENV=prod && \
  composer install --prefer-dist --optimize-autoloader

在安装结束时,它失败了

Generating optimized autoload files


  [Doctrine\DBAL\Exception\DriverException]                                                                  
  An exception occured in driver: sqlSTATE[HY000] [2003] Can't connect to MysqL server on '127.0.0.1' (111)  

  [Doctrine\DBAL\Driver\PDOException]                                        
  sqlSTATE[HY000] [2003] Can't connect to MysqL server on '127.0.0.1' (111)  

  [PDOException]                                                             
  sqlSTATE[HY000] [2003] Can't connect to MysqL server on '127.0.0.1' (111)  


Script Sensio\Bundle\DistributionBundle\Composer\ScriptHandler::clearCache handling the post-install-cmd event terminated with an exception

  [RuntimeException]                                                         
  An error occurred when executing the "'cache:clear --no-warmup'" command.  

现在,我可以使用–no-scripts但是大概我需要在启动容器后再次运行composer install,并且我希望我的容器尽可能准备好.

由于我没有找到很多类似问题的引用,我的应用程序中可能存在一些错误,我怀疑我会回答我自己的问题.我希望在描述它时,我会弄明白.唉,我没有.欢迎提供线索:)