使用docker创建mysql8容器并配置主从复制详细记录

目的：在docker中创建两个mysql8容器，并配置两个mysql主从复制，一主一从。

创建两个mysql容器

1. 在dockerhub中搜索MySQL，按结果页面的命令创建mysql容器。
   我这边准备创建两个mysql-master和mysql-slave,密码都为root

docker run --name mysql-master -e MYSQL_ROOT_PASSWORD=root -d mysql:8

docker run --name mysql-salve -e MYSQL_ROOT_PASSWORD=root -d mysql:8

2. 执行成功后使用docker ps命令查看容器

docker ps
[root@iZbp1dpxwusntf023pd9rxZ slave]# docker ps
CONTAINER ID   IMAGE     COMMAND                  CREATED             STATUS          PORTS                                                                                      NAMES
19b551c223d0   mysql:8   "docker-entrypoint.s…"   About an hour ago   Up 25 minutes   0.0.0.0:3307->3306/tcp, :::3307->3306/tcp, 0.0.0.0:33070->33060/tcp, :::33070->33060/tcp   mysql-slave
3ad9ac61b3b7   mysql:8   "docker-entrypoint.s…"   About an hour ago   Up 29 minutes   0.0.0.0:3306->3306/tcp, :::3306->3306/tcp, 0.0.0.0:33060->33060/tcp, :::33060->33060/tcp   mysql-master

之前配置的端口映射，感觉也不需要所以前面命令就没加-p

检查下两个mysql容器是否连通

使用docker inspect 容器名称 查看下两个容器的ip,由于创建两个容器时没有制定网络，默认两个容器应该是互通的

docker inspect mysql-master

#master网络信息如下：
"Gateway": "172.17.0.1",
"GlobalIPv6Address": "",
"GlobalIPv6PrefixLen": 0,
"IPAddress": "172.17.0.2",

docker inspect mysql-slave
#slave网络信息如下：
 "Gateway": "172.17.0.1",
 "IPAddress": "172.17.0.3",

master的ip为172.17.0.2,slave的IP为172.17.0.3

接下来在其中一个容器内部使用mysql连接另一个容器试试，使用docker exec进入制定容器，比如从slave中使用mysql命令连接master。

docker exec -it mysql-slave bash

#进入slave后使用mysql命令连接master

mysql -uroot -proot -h 172.17.0.2
#操作记录
bash-4.4# mysql -uroot -proot -h 172.17.0.2
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 10
Server version: 8.0.31 MySQL Community Server - GPL

Copyright (c) 2000, 2022, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> 

修改两个mysql的配置文件

配置文件的默认位置在容器中/etc/my.cnf，开始我按dockerhub中mysql页面中将/etc/mysql/conf.d这个目录挂载出来了，然后再宿主机的挂载目录中创建my.cnf配置文件写上配置信息，重启容器配置没有生效，暂时没有寻找原因，也许是我挂载的命令或者配置的方式不对。所以后续我就直接把容器内的/etc/my.cnf直接拷贝出来了，修改完了再拷贝回容器内，才正常生效了。

master的配置文件

1. 拷贝容器内部的配置文件

docker cp mysql-master:/etc/my.cnf ./

2. 然后修改配置，注意同步库不要先创建

#在[mysqld]下添加下列配置项
[mysqld]
server_id=1
#binlog文件名
log-bin=mysql-bin
#忽略库
binlog-ignore-db=mysql
#同步库，不要先创建
binlog-do-db=syncdb
#binlog格式
binlog_format=STATEMENT

3. 保存后复制回容器内部

docker cp my.cnf mysql-master:/etc/

4. 重启容器

docker restart mysql-master

slave的配置文件

1. 拷贝容器内部的配置文件

docker cp mysql-slave:/etc/my.cnf ./

2. 然后修改配置

#在[mysqld]下添加下列配置项
[mysqld]
server_id=2
#中继日志名
relay_log=mysql-relay

3. 保存后复制回容器内部

docker cp my.cnf mysql-salve:/etc/

4. 重启容器

docker restart mysql-slave

在master中创建用户并授权

创建一个“slave”的用户（密码:root）用来同步
先进入master内部

docker exec -it mysql-master bash
#登录mysql
mysql -uroot -proot
#创建用户
create user 'slave'@'%' identified by 'root';
#授权
GRANT REPLICATION SLAVE ON *.* TO 'slave'@'%';
#mysql8需要执行额外的操作
alter user 'slave'@'%' identified with mysql_native_password by 'root';
flush privileges;

操作记录如下

mysql> create user 'slave'@'%' identified by 'root';
Query OK, 0 rows affected (0.15 sec)

mysql>  GRANT REPLICATION SLAVE ON *.* TO 'slave'@'%';
Query OK, 0 rows affected (0.00 sec)

mysql> show grants for 'slave'@'%';
+-----------------------------------------------+
| Grants for slave@%                            |
+-----------------------------------------------+
| GRANT REPLICATION SLAVE ON *.* TO `slave`@`%` |
+-----------------------------------------------+
1 row in set (0.00 sec)
mysql> alter user 'slave'@'%' identified with mysql_native_password by 'root';
Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)

操作完成后查看master的状态，注意状态信息是否和前面配置文件一致，注意File和position列，后续需要在salve中设置

#show master status;
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 |     1142 | syncdb       | mysql            |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

在slave中配置master

进入slave容器，容器内部登录MySQL

docker exec -it mysql-slave bash
mysql -uroot -proot

执行配置master的相关命令，注意master_host是master的ip,master_user和master_password是在master中创建的用户,master_log_file和master_log_pos是master中使用show master status命令查看的内容

 change master to master_host='172.17.0.2',master_user='slave',master_password='root',master_log_file='mysql-bin.000001',master_log_pos=1142;

配置完成后启动slave

#mysql下
start slave;

查看slave状态

#mysql下
show slave status\G;

操作截图:

mysql> start slave;
Query OK, 0 rows affected, 1 warning (0.01 sec)

mysql> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for source to send event
                  Master_Host: 172.17.0.2
                  Master_User: slave
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 1142
               Relay_Log_File: mysql-relay.000002
                Relay_Log_Pos: 326
        Relay_Master_Log_File: mysql-bin.000001
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB: 

如果
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
配置成功。

测试主从复制

当前master和slave中都没有配置文件中的syncdb。
master:

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.00 sec)

slave:

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.01 sec)

在master中创建syncdb

mysql> create database syncdb;
Query OK, 1 row affected (0.01 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| syncdb             |
| sys                |
+--------------------+
5 rows in set (0.01 sec)

在salve中查看，也自动创建了。

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| syncdb             |
| sys                |
+--------------------+
5 rows in set (0.00 sec)

接下来在master创建一些表，插入一些数据测试下
master:

mysql> use syncdb;
Database changed
mysql> create table user(id int,name varchar(10),age int);
Query OK, 0 rows affected (0.03 sec)

mysql> insert into user values(1,'tom',20),(2,'jack',22);
Query OK, 2 rows affected (0.01 sec)
Records: 2  Duplicates: 0  Warnings: 0

mysql> 

在slave中查询下

mysql> use syncdb;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> select * from user;
+------+------+------+
| id   | name | age  |
+------+------+------+
|    1 | tom  |   20 |
|    2 | jack |   22 |
+------+------+------+
2 rows in set (0.00 sec)

mysql> 

ok,至此在docker中配置mysql主从复制完成！

停止主从复制和重置主从连接

stop slave;
reset master;