参考链接
https://www.cnblogs.com/songwenjie/p/9371422.html
1. 首先拉取docker镜像,我们这里使用5.7版本的mysql
docker pull mysql:5.7
2.然后使用此镜像启动容器，这里需要分别启动主从两个容器
Master(主)：
docker run -p 3339:3306 --restart always --name mysql-master -e MYSQL_ROOT_PASSWORD=vsgame12366321 -d mysql:5.7
Slave(从)：
docker run -p 3340:3306 --restart always --name mysql-slave1 -e MYSQL_ROOT_PASSWORD=vsgame12366321 -d mysql:5.7
docker run -p 3341:3306 --restart always --name mysql-slave2 -e MYSQL_ROOT_PASSWORD=vsgame12366321 -d mysql:5.7
docker run -p 3342:3306 --restart always --name mysql-slave3 -e MYSQL_ROOT_PASSWORD=vsgame12366321 -d mysql:5.7
配置Master(主)
1.进入mysql-master容器
docker -it mysql-master bash
2.进入mysql目录；配置my.cnf配置文件；
cd etc/mysql
vi my.cnf(这条命令在docker里面会报一个错误：bash: vi: command not found)
2.1 解决办法；就是更新本地vim，从新安装一下vim
apt-get update
apt-get install vim
2.2 mysql-master的my.cnf配置文件
[mysqld]
## 同一局域网内注意要唯一
server-id=100
## 开启二进制日志功能，可以随便取（关键）
log-bin=mysql-bin
2.3 在Master数据库创建数据同步用户，授予用户 slave REPLICATION SLAVE权限和REPLICATION CLIENT权限，用于在主从库之间同步数据。
CREATE USER 'slave1'@'%' IDENTIFIED BY 'vsgame12366321';
GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'slave1'@'%';
2.4 使配置生效
docker restart mysql-master
配置Slave(从)
跟mysql-mstar 1和2，2.1步骤一致
2.2 配置mysql-salve的my.cnf配置文件
[mysqld]
## 设置server_id,注意要唯一
server-id=101
## 开启二进制日志功能，以备Slave作为其它Slave的Master时使用
log-bin=mysql-slave-bin
## relay_log配置中继日志
relay_log=edu-mysql-relay-bin
使配置生效
docker restart mysql-slave
进入mysql-master容器,查看是否实现了主从复制
1.进入容器：docker exec -it mysql-master bash
2.连接mysql : mysql -uroot -p 123456
3.查看：show master status
2.1 配置成功如下：
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 | 617 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
注意：File和Position字段的值后面将会用到，在后面的操作完成之前，需要保证Master库不能做任何操作，否则将会引起状态变化，File和Position字段的值变化
2.2 在Slave 中进入 mysql，执行
change master to master_host='172.17.0.2', master_user='slave1', master_password='vsgame12366321', master_port=3306, master_log_file='mysql-bin.000002', master_log_pos= 154, master_connect_retry=30;
2.2.1 命令说明：
master_host ：Master的地址，指的是容器的独立ip,可以通过docker inspect --format='{{.NetworkSettings.IPAddress}}' 容器名称|容器id查询容器的ip
master_port：Master的端口号，指的是容器的端口号
master_user：用于数据同步的用户
master_password：用于同步的用户的密码
master_log_file：指定 Slave 从哪个日志文件开始复制数据，即上文中提到的 File 字段的值
master_log_pos：从哪个 Position 开始读，即上文中提到的 Position 字段的值
master_connect_retry：如果连接失败，重试的时间间隔，单位是秒，默认是60秒
在Slave 中的mysql终端执行show slave status \G;用于查看主从同步状态。
容器ip
mysql-master: 172.17.0.2
mysql-slave1: 172.17.0.3
mysql-slave2: 172.17.0.3
mysql-slave3: 172.17.0.6
2.3 在Slave 中的mysql终端执行show slave status \G;用于查看主从同步状态
mysql> show slave status \G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 172.17.0.2
Master_User: slave
Master_Port: 3306
Connect_Retry: 30
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 617
Relay_Log_File: edu-mysql-relay-bin.000002
Relay_Log_Pos: 320
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: No
Slave_SQL_Running: No
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 617
Relay_Log_Space: 531
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 100
Master_UUID: 9147af13-961e-11e9-b793-0242ac110002
Master_Info_File: /var/lib/mysql/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
1 row in set (0.00 sec)
2.4 使用start slave开启主从复制过程，然后再次查询主从同步状态show slave status \G;
1. 运行命令：start slave
2. show slave status \G;
mysql> show slave status \G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 172.17.0.2
Master_User: slave
Master_Port: 3306
Connect_Retry: 30
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 617
Relay_Log_File: edu-mysql-relay-bin.000002
Relay_Log_Pos: 320
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 617
Relay_Log_Space: 531
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 100
Master_UUID: 9147af13-961e-11e9-b793-0242ac110002
Master_Info_File: /var/lib/mysql/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
1 row in set (0.00 sec)
测试主从模式是否成功
在主库中新建数据库为testDb,刷新从库是否也有testDb；如果有，这成功，否则失败
