Docker搭建MySQL主从复制
- 主从服务器上分别安装Docker
1.1 Docker 要求 CentOS 系统的内核版本高于 3.10
[root@localhost ~]# uname -r 3.10.0-693.el7.x86_641.2 确保 yum 包更新到最新。
[root@localhost ~]# sudo yum update Loaded plugins: fastestmirror, langpacks Loading mirror speeds from cached hostfile* base: mirrors.cqu.edu.cn* extras: mirrors.cqu.edu.cn* updates: mirrors.cqu.edu.cn base | 3.6 kB 00:00:00 docker-ce-stable | 3.5 kB 00:00:00 extras | 2.9 kB 00:00:00 updates | 2.9 kB 00:00:001.3 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 lvm2 Loaded plugins: fastestmirror, langpacks Loading mirror speeds from cached hostfile* base: mirrors.cqu.edu.cn* extras: mirrors.cqu.edu.cn* updates: mirrors.cqu.edu.cn Package yum-utils-1.1.31-52.el7.noarch already installed and latest version Package device-mapper-persistent-data-0.8.5-1.el7.x86_64 already installed and latest version Package 7:lvm2-2.02.185-2.el7_7.2.x86_64 already installed and latest version Nothing to do1.4 设置yum源
[root@localhost ~]# sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo Loaded plugins: fastestmirror, langpacks adding repo from: https://download.docker.com/linux/centos/docker-ce.repo grabbing file https://download.docker.com/linux/centos/docker-ce.repo to /etc/yum.repos.d/docker-ce.repo repo saved to /etc/yum.repos.d/docker-ce.repo1.5 安装docker
[root@localhost ~]# sudo yum install docker-ce Loaded plugins: fastestmirror, langpacks Loading mirror speeds from cached hostfile* base: mirrors.cqu.edu.cn* extras: mirrors.cqu.edu.cn* updates: mirrors.cqu.edu.cn Package 3:docker-ce-19.03.8-3.el7.x86_64 already installed and latest version Nothing to do1.6 启动docker并设置docker自动启动
[root@localhost ~]# sudo systemctl start docker [root@localhost ~]# sudo systemctl enable docker1.7 检测docker是否安装成功
[root@localhost ~]# docker version Client: Docker Engine - CommunityVersion: 19.03.8API version: 1.40Go version: go1.12.17Git commit: afacb8bBuilt: Wed Mar 11 01:27:04 2020OS/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 2020OS/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/docker sudo tee /etc/docker/daemon.json <<-'EOF' {"registry-mirrors": ["https://rdwyjupq.mirror.aliyuncs.com"] } EOF sudo systemctl daemon-reload sudo systemctl restart docker2.2 安装MySQL
2.2.1 下载MySQL
[root@localhost ~]# docker pull mysql Using default tag: latest latest: Pulling from library/mysql c499e6d256d6: 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:b69d0b62d02ee1eba8c7aeb32eba1bb678b6cfa4ccfb211a5d7931c7755dc4a8 Status: Downloaded newer image for mysql:latest docker.io/library/mysql:latest 2.2.2 查看MySQL镜像
[root@localhost ~]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE mysql latest 9228ee8bac7a 4 days ago 547MB 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" mysql 05d161e69f3b2e3e4ebaa50f822934599a31e7ade330e1440a68aec9e404f7ae 2.2.5 复制配置文件
[root@localhost conf]# docker cp mysql:/etc/mysql/my.cnf /root/mysql/conf/ 2.2.6 停止并删容器
[root@localhost conf]# docker stop mysql mysql [root@localhost conf]# docker rm mysql mysql 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/my.cnf,dst=/etc/mysql/my.cnf --mount ty pe=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my.cnf，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my.cnf，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
