我当前的Dockerfile如下所示:FROMubuntu:14.04ENVDEBIAN_FRONTENDnoninteractiveENVINITRDNoENVLANGen_US.UTF-8#MariaDBVersionsENVMARIADB_MAJOR5.5ENVMARIADB_VERSION5.5.55+maria-1~trusty#CreatemysqluserandgroupRUNgroupadd-rmysql&&useradd-r-gmysqlmysql#InstallneededdependenciesRUNapt-getupdate&&apt-getinstall-y-