1. docker下mysql（8.0以上版本） 主从配置

请自行先安装完docker和docker-compose
mysql8.0以后的版本与5.7的配置有一点点不同，网上不少都是5.X版本的配置方法，并不适用于8.0的，在这里总结一下我配置成功的过程。
我的安装环境：

在这里插入图片描述

1. 在主机上安装docker之后，从官网拉取最新镜像

docker pull mysql:latest

安装的mysql最新版本为：

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2. 编写docker-compose.yml，以及两个数据库配置文件master.my.cnf, slave.my.cnf，这里先建个目录，在目录下创建需要的三个文件：
   mkdir mysql_docker_file && cd mysql_docker_file
touch docker-compose.yml master.my.cnf slave.my.cnf
   docker-compose.yml内容如下：

主要将mysql-master和mysql-slave配置在172.18.2.0/24同一个网段，
然后做了个存储空间的映射，将两个容器的数据内容都映射到宿主机的/root/data目录下

version: '2'
services:
  mysql-master:
   image: mysql
   networks:
       mysql_net:
         ipv4_address: 172.18.2.2
   volumes:
     - /root/data/mysql-master:/var/lib/mysql
     - /root/mysql_docker_file/master.my.cnf:/etc/mysql/my.cnf
   ports:
     - "33067:3306"
   environment:
     - MYSQL_DATABASE=root
     - MYSQL_ROOT_PASSWORD=123456
  mysql-slave:
   image: mysql
   networks:
       mysql_net:
         ipv4_address: 172.18.2.3
   volumes:
     - /root/data/mysql-slave:/var/lib/mysql
     - /root/mysql_docker_file/slave.my.cnf:/etc/mysql/my.cnf
   ports:
     - "33068:3306"
   environment:
     - MYSQL_DATABASE=root
     - MYSQL_ROOT_PASSWORD=123456
networks:
  mysql_net:
    driver: bridge
    ipam:
      driver: default
      config:
      - subnet: 172.18.2.0/24

新建master.my.cnf，内容如下：
只在默认的文件加了三条：
server-id=111 #id号
innodb_flush_log_at_trx_commit=2
sync_binlog=1
innodb_flush_log_at_trx_commit和sync_binlog请参考点击这篇文章，讲得很清楚

#copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
#
## 1.1. This program is free software; you can redistribute it and/or modify
## 1.2. it under the terms of the GNU General Public License as published by
## 1.3. the Free Software Foundation; version 2 of the License.
##
## 1.4. This program is distributed in the hope that it will be useful,
## 1.5. but WITHOUT ANY WARRANTY; without even the implied warranty of
## 1.6. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## 1.7. GNU General Public License for more details.
##
## 1.8. You should have received a copy of the GNU General Public License
## 1.9. along with this program; if not, write to the Free Software
## 1.10. Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
#
##
## 1.11. The MySQL  Server configuration file.
##
## 1.12. For explanations see
## 1.13. http://dev.mysql.com/doc/mysql/en/server-system-variables.html
#
[mysqld]
pid-file        = /var/run/mysqld/mysqld.pid
socket          = /var/run/mysqld/mysqld.sock
datadir         = /var/lib/mysql
secure-file-priv= NULL

## 1.14. Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0

#
## 1.15. Custom config should go here
!includedir /etc/mysql/conf.d/

server-id=111
innodb_flush_log_at_trx_commit=2  
sync_binlog=1  

新建slave.my.cnf，内容如下：
在默认文件下添加了4条
server-id=222
innodb_flush_log_at_trx_commit=2
sync_binlog=1
relay_log_recovery=0

#copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
#
## 1.16. This program is free software; you can redistribute it and/or modify
## 1.17. it under the terms of the GNU General Public License as published by
## 1.18. the Free Software Foundation; version 2 of the License.
##
## 1.19. This program is distributed in the hope that it will be useful,
## 1.20. but WITHOUT ANY WARRANTY; without even the implied warranty of
## 1.21. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## 1.22. GNU General Public License for more details.
##
## 1.23. You should have received a copy of the GNU General Public License
## 1.24. along with this program; if not, write to the Free Software
## 1.25. Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
#
##
## 1.26. The MySQL  Server configuration file.
##
## 1.27. For explanations see
## 1.28. http://dev.mysql.com/doc/mysql/en/server-system-variables.html
#
[mysqld]
pid-file        = /var/run/mysqld/mysqld.pid
socket          = /var/run/mysqld/mysqld.sock
datadir         = /var/lib/mysql
secure-file-priv= NULL
## 1.29. Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0

#
## 1.30. Custom config should go here
!includedir /etc/mysql/conf.d/
server-id=222
innodb_flush_log_at_trx_commit=2  #
sync_binlog=1  #开启binlog日志同步功能
relay_log_recovery=0

master.my.cnf和slave.my.cnf的server-id一定不能一样，而innodb_flush_log_at_trx_commit，sync_binlog，relay_log_recovery等参数的设置会影响到主从复制的性能，有兴趣的可以进行更多的了解。

3. 全部文件都写完后，终于可以创建容器了，执行：
   docker-compose up -d
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   执行docker ps -a查看是否创建容器成功，失败的话请docker logs 容器ID 查看日志并解决，第一列为容器ID
   在这里插入图片描述
4. 主数据库操作流程如下：
   进入master容器：docker exec -it 容器的ID号 /bin/bash
   登录数据库:mysql -uroot -p123456
   创建账号：create user 'slave'@'172.18.2.3' identified by '123456';, 注意填从库的IP
   后授权：grant replication slave on *.* to 'slave'@'172.18.2.3' with grant option;
   刷新下权限：flush privileges;
   查看master状态：show master status;,记录这里的file和Position，后面要用
   锁库：flush tables with read lock;
   退出数据库：exit
   导出master整个数据库内容：mysqldump -uroot -p123456 -A --events > backup.sql
   将生成的backup.sql想办法弄到slave容器，这里通过宿主机做中介：mv backup.sql /var/lib/mysql
   退出容器：exit
5. 回到宿主机后，进入/root/data/mysql-master，将backup.sql移动到/root/data/mysql-slave
6. 从数据库操作流程如下：
   进入slave容器：docker exec -it 容器的ID号 /bin/bash
   导入master的数据库数据：mysql < /var/lib/mysql/backup.sql -uroot -p123456
   登录数据库:mysql -uroot -p123456
   可以看到有slave账号：select user from mysql.user;
   连接master的设置：注意填主库ip,上面记录的file和position

change master to \
master_host='172.18.2.2',
master_port=3306,
master_user='slave',
master_password='123456',
master_log_file='binlog.000002',
master_log_pos=892,
get_master_public_key=1;

开启从服务：start slave;
执行show slave status\G;，看到后面两个yes就成立

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8. 再次登录主库：
   进入master容器：docker exec -it 容器的ID号 /bin/bash
   登录数据库:mysql -uroot -p123456
   解锁：unlock tables；
   到了这里就大功告成了！！！
   可以测试一下：
   在主库创建一个名为test的数据库
   create database test;
   去从库执行：
   show databases;可以看到也有也test库
   在这里插入图片描述