1、拉取镜像

注：国内拉取镜像需要先配置镜像加速器地址

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

docker pull mysql:8.0.46

2、准备my.cnf配置文件和docker compose配置文件

注：先临时启动mysql服务，拷贝默认的my.cnf文件

docker run -d --name mysql -e MYSQL_ROOT_PASSWORD=123456 mysql:8.0.46
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mysql主配置文件
vim /opt/mysql/master/my.cnf
[mysqld]
server-id = 1                      # 主库的唯一ID，必须比从库小
log-bin = mysql-bin                # 开启二进制日志
binlog_format = ROW                # 推荐使用行级复制，更安全

# 修改mysql从配置文件
vim /opt/mysql/slave/my.cnf
[mysqld]
server-id = 2                      # 主库的唯一ID，必须比从库小
log-bin = mysql-bin                # 开启二进制日志
binlog_format = ROW                # 推荐使用行级复制，更安全

# 准备docker compose配置文件
cat > mysql-8.0.yml <<'EOF'
services:
  mysql-master:
    container_name: mysql-master
    image: mysql:8.0.46
    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:8.0.46
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: 123456
    volumes:
      - "/var/lib/mysql"
      - "/opt/mysql/slave/my.cnf:/etc/my.cnf"
    ports:
      - "3307:3306"
EOF

3、启动mysql容器服务

[root@develop ~]# docker compose -f mysql-8.0.yml up -d
[+] Running 3/3
 ✔ Network root_default    Created                                                                                       0.0s 
 ✔ Container mysql-slave   Started                                                                                       0.4s 
 ✔ Container mysql-master  Started    

4、配置mysql主服务

# 进入mysql主容器并登录mysql服务
[root@develop ~]# docker exec -it mysql-master bash
bash-5.1# mysql -uroot -p123456

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

# 查看主服务状态
mysql> SHOW MASTER STATUS\G;
*************************** 1. row ***************************
             File: mysql-bin.000003
         Position: 827
     Binlog_Do_DB: 
 Binlog_Ignore_DB: 
Executed_Gtid_Set: 
1 row in set (0.00 sec)

5、配置mysql从服务

# 进入mysql容器并登录mysql服务
[root@develop ~]# docker exec -it mysql-slave bash
bash-5.1# mysql -uroot -p123456

# 配置主从连接并启动
CHANGE REPLICATION SOURCE TO
    SOURCE_HOST='192.168.80.100',
    SOURCE_USER='repl',
    SOURCE_PASSWORD='123456',
    SOURCE_LOG_FILE='mysql-bin.000003',
    SOURCE_LOG_POS=827;

START REPLICA;

6、检查主从复制状态

mysql> SHOW REPLICA STATUS\G;
*************************** 1. row ***************************
             Replica_IO_State: Waiting for source to send event
                  Source_Host: 192.168.80.100
                  Source_User: repl
                  Source_Port: 3306
                Connect_Retry: 60
              Source_Log_File: mysql-bin.000003
          Read_Source_Log_Pos: 827
               Relay_Log_File: a499205f6cf4-relay-bin.000002
                Relay_Log_Pos: 326
        Relay_Source_Log_File: mysql-bin.000003
           Replica_IO_Running: Yes # 表示主从复制正常
          Replica_SQL_Running: Yes # 表示主从复制正常

7、检查主从延迟

mysql> SHOW REPLICA STATUS\G;
*************************** 1. row ***************************
             Replica_IO_State: Waiting for source to send event
                  Source_Host: 192.168.80.100
                  Source_User: repl
                  Source_Port: 3306
                Connect_Retry: 60
              Source_Log_File: mysql-bin.000003
          Read_Source_Log_Pos: 827
               Relay_Log_File: a499205f6cf4-relay-bin.000002
                Relay_Log_Pos: 326
        Relay_Source_Log_File: mysql-bin.000003
           Replica_IO_Running: Yes
          Replica_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_Source_Log_Pos: 827
              Relay_Log_Space: 543
              Until_Condition: None
               Until_Log_File: 
                Until_Log_Pos: 0
           Source_SSL_Allowed: No
           Source_SSL_CA_File: 
           Source_SSL_CA_Path: 
              Source_SSL_Cert: 
            Source_SSL_Cipher: 
               Source_SSL_Key: 
        Seconds_Behind_Source: 0 # 表示主从延迟时间，时间越短越好。