复制文件到容器

# docker cp my.cnf local_mysql_new:/etc/mysql/conf.d

复制文件my.cnf 到容器名为：local_mysql_new的，文件夹为/etc/mysql/conf.d的目录下面

# docker cp local_mysql_new:/etc/mysql/conf.d/my.cnf  /data/mysql/mysql/conf.d