Docker搭建MySQL主从复制

1.1 Docker 要求 CentOS 系统的内核版本高于 3.10

[root@localhost ~]# uname -r3.10.0-693.el7.x86_64

1.2 确保 yum 包更新到最新。

[root@localhost ~]# sudo yum updateLoaded plugins: fastestmirror, langpacksLoading mirror speeds from cached hostfile* base: mirrors.* extras: mirrors.* updates: mirrors.base | 3.6 kB 00:00:00docker-ce-stable | 3.5 kB 00:00:00extras | 2.9 kB 00:00:00updates | 2.9 kB 00:00:00

1.3 安装需要的软件包， yum-util 提供yum-config-manager功能，另外两个是devicemapper驱动依赖的

[root@localhost ~]# sudo yum install -y yum-utils device-mapper-persistent-data lvm2Loaded plugins: fastestmirror, langpacksLoading mirror speeds from cached hostfile* base: mirrors.* extras: mirrors.* updates: mirrors.Package yum-utils-1.1.31-52.el7.noarch already installed and latest versionPackage device-mapper-persistent-data-0.8.5-1.el7.x86_64 already installed and latest versionPackage 7:lvm2-2.02.185-2.el7_7.2.x86_64 already installed and latest versionNothing to do

1.4 设置yum源

[root@localhost ~]# sudo yum-config-manager --add-repo /linux/centos/docker-ce.repoLoaded plugins: fastestmirror, langpacksadding repo from: /linux/centos/docker-ce.repograbbing file /linux/centos/docker-ce.repo to /etc/yum.repos.d/docker-ce.reporepo saved to /etc/yum.repos.d/docker-ce.repo

1.5 安装docker

[root@localhost ~]# sudo yum install docker-ceLoaded plugins: fastestmirror, langpacksLoading mirror speeds from cached hostfile* base: mirrors.* extras: mirrors.* updates: mirrors.Package 3:docker-ce-19.03.8-3.el7.x86_64 already installed and latest versionNothing to do

1.6 启动docker并设置docker自动启动

[root@localhost ~]# sudo systemctl start docker[root@localhost ~]# sudo systemctl enable docker

1.7 检测docker是否安装成功

[root@localhost ~]# docker versionClient: Docker Engine - CommunityVersion: 19.03.8API version: 1.40Go version: go1.12.17Git commit: afacb8bBuilt: Wed Mar 11 01:27:04 OS/Arch: linux/amd64Experimental:falseServer: Docker Engine - CommunityEngine:Version:19.03.8API version:1.40 (minimum version 1.12)Go version: go1.12.17Git commit: afacb8bBuilt: Wed Mar 11 01:25:42 OS/Arch:linux/amd64Experimental:falsecontainerd:Version:1.2.13GitCommit: 7ad184331fa3e55e52b890ea95e65ba581ae3429runc:Version:1.0.0-rc10GitCommit: dc9208a3303feef5b3839f4323d9beb36df0a9dddocker-init:Version:0.18.0GitCommit: fec3683

docker更换国内阿里仓库，并下载安装MySQL

2.1 docker更换国内阿里仓库

sudo mkdir -p /etc/dockersudo tee /etc/docker/daemon.json <<-'EOF'{"registry-mirrors": ["https://rdwyjupq."]}EOFsudo systemctl daemon-reloadsudo systemctl restart docker

2.2 安装MySQL

​ 2.2.1 下载MySQL

[root@localhost ~]# docker pull mysqlUsing default tag: latestlatest: Pulling from library/mysqlc499e6d256d6: Pull complete 22c4cdf4ea75: Pull complete 6ff5091a5a30: Pull complete 2fd3d1af9403: Pull complete 0d9d26127d1d: Pull complete 54a67d4e7579: Pull complete fe989230d866: Pull complete 3a808704d40c: Pull complete 826517d07519: Pull complete 69cd125db928: Pull complete b5c43b8c2879: Pull complete 1811572b5ea5: Pull complete Digest: sha256:b69d0b62d02ee1eba8c7aeb32eba1bb678b6cfa4ccfb211a5d7931c7755dc4a8Status: Downloaded newer image for mysql:latestdocker.io/library/mysql:latest

​ 2.2.2 查看MySQL镜像

[root@localhost ~]# docker imagesREPOSITORYTAG IMAGE ID CREATED SIZEmysqllatest 9228ee8bac7a 4 days ago547MB

​ 2.2.3 创建MySQL的挂载文件目录（日志、数据、配置）

[root@localhost ~]# mkdir -p /root/mysql/data /root/mysql/logs /root/mysql/conf

​ 2.2.4 先启动容器（为了复制配置文件）（这种做法显得多余，但是Docker不是很精通的我没想到更好的办法，请各位大神指导）

[root@localhost conf]# docker run -d -p 3306:3306 --name mysql -e MYSQL_ROOT_PASSWORD="123456" mysql05d161e69f3b2e3e4ebaa50f822934599a31e7ade330e1440a68aec9e404f7ae

​ 2.2.5 复制配置文件

[root@localhost conf]# docker cp mysql:/etc/mysql/f /root/mysql/conf/

​ 2.2.6 停止并删容器

[root@localhost conf]# docker stop mysqlmysql[root@localhost conf]# docker rm mysqlmysql

​ 2.2.7 重新启动容器（加上挂载）

[root@localhost conf]# docker run --name mysql -p 3306:3306 -e MYSQL_ROOT_PASSWORD=123456 --mount type=bind,src=/root/mysql/conf/f,dst=/etc/mysql/f --mount type=bind,src=/root/mysql/data,dst=/var/lib/mysql --mount type=bind,src=/root/mysql/logs,dst=/logs --restart=on-failure:3 -d mysql64824c7e84ceb3513b65a375c55f2c53bc653f95b119008296122b13ff632ba1

​ 2.2.8 进入MySQL查询现有字符集，结果都是utf8mb4

show variables like '%char%';

​ 2.2.9 在挂载的配置文件更改字符集

character-set-server=utf8default-character-set=utf8default-character-set=utf8

​ 2.2.10 重启docker容器，并查看字符集已经更改，证明挂载的配置文件有效

搭建主从复制数据库

3.1 配置主Master库

​ 3.1.1 进入主库挂载配置文件f，加入以下配置并重启docker容器

[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

​ 3.1.2 在主Master库执行语句

CREATE USER 'slave'@'%' IDENTIFIED BY '123456';GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'slave'@'%';

​ 为防止后面出现报错[Authentication plugin 'caching_sha2_password' cannot be loaded]，执行下面语句

ALTER USER 'slave'@'%' IDENTIFIED BY 'password' PASSWORD EXPIRE NEVER; #修改加密规则 ALTER USER 'slave'@'%' IDENTIFIED WITH mysql_native_password BY 'password'; #更新一下用户的密码 FLUSH PRIVILEGES;alter user 'slave'@'%' identified by '123456';

最后执行语句获取File， Position

show master status;

3.2 配置从Slave库

​ 3.2.1 进入从库挂载配置文件f，加入以下配置并重启docker容器

[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

​ 3.2.2 链接主从库，在从库执行语句

change master to master_host='192.168.47.128', master_user='slave', master_password='123456', master_port=3306, master_log_file='mysql-bin.000001', master_log_pos= 5938, master_connect_retry=30;

master_host：Master的地址

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

​ 3.2.3 查看主从同步状态

show slave status ;

​ 正常情况下，SlaveIORunning 和 SlaveSQLRunning 都是No，因为我们还没有开启主从复制过程。

3.2.4 开启主从复制

start slave;

重新查看主从同步状态， 这时SlaveIORunning 和 SlaveSQLRunning 都是Yes，如果你的SlaveIORunning 和 SlaveSQLRunning 其中一个是Connecting或者No，就证明配置有错，查看Last_IO_Error报错的详细信息

通过下面命令，删除已经配置的主从链接信息，重新进行配置

stop slave;reset master;

3.2.5 测试主从复制，最简单的方式是在主库建立个新库，这时，从库会自动同步