使用 Docker Compose 搭建一个 MySQL 主从服务

安装 Docker for Mac

先安装 Docker for Mac

准备好文件

docker-compose.yml

version: '3'
services:
  mysql-master:
    environment:
      - MYSQL_ALLOW_EMPTY_PASSWORD=yes
    ports:
      - "3306:3306"
    build:
      context: .
      dockerfile: ./docker/mysql/master/DockerFile
    links:
      - mysql-slave
  mysql-slave:
    environment:
      - MYSQL_ALLOW_EMPTY_PASSWORD=yes
    ports:
      - "3406:3306"
    build:
      context: .
      dockerfile: ./docker/mysql/slave/DockerFile

docker/mysql/master/DockerFile

FROM mysql:5.6.40

WORKDIR /

COPY docker/mysql/master/my.cnf /etc/my.cnf

docker/mysql/master/my.cnf

[mysqld]
# [必须]启用二进制日志
log-bin=mysql-bin 
# [必须]服务器唯一ID，默认是1，一般取IP最后一段  
server-id=1
## 复制过滤：也就是指定哪个数据库不用同步（mysql库一般不同步）
binlog-ignore-db=mysql

docker/mysql/slave/DockerFile

FROM mysql:5.6.40

WORKDIR /

COPY docker/mysql/slave/my.cnf /etc/my.cnf

docker/mysql/slave/my.cnf

[mysqld]
# [必须]服务器唯一ID，默认是1，一般取IP最后一段  
server-id=2

构建镜像

docker-compose build

启动容器

docker-compose up -d

MySQL 主从设置

进入 MySQL Master

创建同步用户

create user repl;

设置同步用户的权限

GRANT REPLICATION SLAVE ON *.* TO 'repl'@'%' IDENTIFIED BY 'repl';

显示 master 状态

mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000004 |      397 |              | mysql            |                   |
+------------------+----------+--------------+------------------+-------------------+

记住 File 和 Position 里面的值，比如 mysql-bin.000004 和 397。

进入 MySQL Slave

设置连接 Master 的参数

记得修改 MASTER_LOG_FILE 和 MASTER_LOG_POS 的值。

CHANGE MASTER TO
    MASTER_HOST='mysql-master',
    MASTER_USER='repl',
    MASTER_PASSWORD='repl',
    MASTER_LOG_FILE='mysql-bin.000004',
    MASTER_LOG_POS=397;

启动 slave 服务

start slave;

显示 slave 状态

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: mysql-master
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000004
          Read_Master_Log_Pos: 397
               Relay_Log_File: mysqld-relay-bin.000002
                Relay_Log_Pos: 596
        Relay_Master_Log_File: mysql-bin.000004
             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: 710
              Relay_Log_Space: 770
              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: 1
                  Master_UUID: c67c8183-feb2-11e8-9a5e-0242ac120006
             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 the slave I/O thread to update it
           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
1 row in set (0.00 sec)

当 Slave_IO_Running 和 Slave_SQL_Running 为 Yes 时，说明同步服务正常。

这时候就可以运行一些 SQL 语句来验证同步服务是否正常了。