1、拉取镜像

注：国内下载需要配置镜像加速器

cat > /etc/docker/daemon.json << 'EOF'
{
    "registry-mirrors": [ "https://docker.m.daocloud.io" ]
}
EOF
systemctl daemon-reload
systemctl restart docker

docker pull mysql:5.7

2、准备my.cnf配置文件和docker compose配置文件

注：默认的my.cnf配置文件可以从先启动Mysql容器服务，然后从容器里拷贝出来。

docker run -d --name mysql -e MYSQL_ROOT_PASSWORD=123456 mysql:5.7
docker cp mysql:/etc/my.cnf .

# 创建配置目录
mkdir -p /opt/mysql/{master,slave}

# 拷贝配置文件
\cp -f my.cnf /opt/mysql/master/
\cp -f my.cnf /opt/mysql/slave/

# 修改配置文件
vim /opt/mysql/master/my.cnf
[mysqld]
server-id = 1                     # 唯一ID，必须与从库不同
log-bin = mysql-bin              # 开启并设置二进制日志文件名
binlog_format = ROW              # 推荐使用ROW格式
expire_logs_days = 7             # 日志保留天数，避免磁盘占满

vim /opt/mysql/slave/my.cnf
server-id = 2                     # 唯一ID，必须与从库不同
log-bin = mysql-bin              # 开启并设置二进制日志文件名
binlog_format = ROW              # 推荐使用ROW格式
expire_logs_days = 7             # 日志保留天数，避免磁盘占满

# 准备docker compose配置文件
```yaml
services:
  mysql-master:
    container_name: mysql-master
    image: mysql:5.7
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: 123456
    volumes:
      - "/var/lib/mysql"
      - "/opt/mysql/master/my.cnf:/etc/my.cnf"
    ports:
      - "3306:3306"
  mysql-slave:
    container_name: mysql-slave
    image: mysql:5.7
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: 123456
    volumes:
      - "/var/lib/mysql"
      - "/opt/mysql/slave/my.cnf:/etc/my.cnf"
    ports:
      - "3307:3306"

3、启动mysql服务

[root@develop ~]# docker compose -f mysql-5.7.yml up -d
[+] Running 3/3
 ✔ Network root_default    Created                                                                                       0.0s 
 ✔ Container mysql-slave   Started                                                                                       0.3s 
 ✔ Container mysql-master  Started     

4、配置mysql主服务

# 进入mysql-master容器并登录mysql服务
[root@develop ~]# docker exec -it mysql-master bash
bash-4.2# mysql -uroot -p123456

# 创建复制用户
CREATE USER 'repl'@'%' IDENTIFIED BY '123456';
GRANT REPLICATION SLAVE ON *.* TO 'repl'@'%';
FLUSH PRIVILEGES;

# 查看主服务状态
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000003 |      747 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

5、配置mysql从服务

# 进入mysql-slave容器并登录mysql服务
[root@develop ~]# docker exec -it mysql-slave bash
bash-4.2# mysql -uroot -p123456

# 配置主从连接并启动
CHANGE MASTER TO
  MASTER_HOST='192.168.80.100',
  MASTER_USER='repl',
  MASTER_PASSWORD='123456',
  MASTER_LOG_FILE='mysql-bin.000003',
  MASTER_LOG_POS=747; 

START SLAVE;

6、检查主从服务状态

mysql> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.80.100
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000003
          Read_Master_Log_Pos: 747
               Relay_Log_File: 5fc9a5d8447d-relay-bin.000002
                Relay_Log_Pos: 320
        Relay_Master_Log_File: mysql-bin.000003
             Slave_IO_Running: Yes  # 表示主从复制正常
            Slave_SQL_Running: Yes  # 表示主从复制正常

7、检查主从延迟

mysql> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.80.100
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000003
          Read_Master_Log_Pos: 747
               Relay_Log_File: 5fc9a5d8447d-relay-bin.000002
                Relay_Log_Pos: 320
        Relay_Master_Log_File: mysql-bin.000003
             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: 747
              Relay_Log_Space: 534
              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  # 表示主从延迟时间，时间越短越好。