1.版本mysql:5.7.38

最新官方MySQL(5.7.19)的docker镜像在创建时映射的配置文件目录有所不同，在此记录并分享给大家： 官方原文：

The MySQL startup configuration is specified in the file /etc/mysql/my.cnf, and that file in turn includes any files found in the /etc/mysql/conf.d directory that end with .cnf. Settings in files in this directory will augment and/or override settings in /etc/mysql/my.cnf. If you want to use a customized MySQL configuration, you can create your alternative configuration file in a directory on the host machine and then mount that directory location as /etc/mysql/conf.d inside the mysql container.

大概意思是说：

MySQL(5.7.19)的默认配置文件是 /etc/mysql/my.cnf 文件。如果想要自定义配置，建议向 /etc/mysql/conf.d 目录中创建 .cnf 文件。新建的文件可以任意起名，只要保证后缀名是 cnf 即可。新建的文件中的配置项可以覆盖 /etc/mysql/my.cnf 中的配置项。

具体操作： 首先需要创建将要映射到容器中的目录以及.cnf文件，然后再创建容器

pwd
/opt
mkdir -p docker_v/mysql/conf
cd docker_v/mysql/conf
touch my.cnf
docker run -p 3307:3306 --name mysql57 -v /opt/docker_v/mysql/conf:/etc/mysql/conf.d -e MYSQL_ROOT_PASSWORD=12345678 -d mysql:5.7.38