基于Kubernetes搭建MySQL主从集群
愿你,忠于自己,活得像自己。
清单:
Name | Version |
---|---|
CentOS | 7 |
Kubernetes | 1.9.0 |
Docker | 17.09.1-ce |
MySQL | 5.7 |
前言
令我始料不及的出差活动中,开始接触Kubernetes并被要求搭建基于此的MySQL主从集群,由于笔者在Linux、Kubernetes等方面都是小白,故此展开了填坑活动,写本文目的只是为了让其他程序猿少踩坑,下面简单介绍下MySQL主从集群。
我们用MySQL集群的分布式部署来实现MySQL主从模式,在MySQL集群中,Master节点主要负责数据的分发和slave节点的管理。因此Master节点主要负责数据的写入和分发(包括insert、update、delete)。而slave节点主要负责数据的读取(包括select)。基本的master和slave的分工作业,如下图所示。
MySQL集群架构
MySQL集群在主从模式下实现一台服务充当主服务器,其他一台或者多台服务器充当从服务器。下面我们开始搭建。
一、安装MySQL
经深入研究后发现,docker镜像不用自行安装MySQL,如需安装MySQL,请转我的另一篇文章:https://www.jianshu.com/p/a6c5ec995660
二、构建Docker镜像
构建镜像需要以下操作,先简单说明后面步骤将此部分内容写入Dockerfile中
master配置
文件/etc/my.cnf中[mysqld]下添加配置
log-bin=mysql-bin server-id=1
重启MySQL
# service mysqld restart
创建同步账号
# mysql -u root -p# create user 'sync'@'%' identified by 'MySQL@lipuan.2018';
赋予同步账号远程权限
# grant replication slave on *.* to 'sync'@'%' identified by 'MySQL@lipuan.2018';
slave配置
文件/etc/my.cnf中[mysqld]下添加配置
log-bin=mysql-bin server-id=2
重启MySQL
# service mysqld restart
配置主机IP
# mysql -u root -p# change master to master_host='x.x.x.x',master_user='sync',master_password='MySQL@lipuan.2018';
注意: server-id为主机标识,不能重复。x.x.x.x'为master服务器IP
下面我们将以上的配置写入Dockerfile中
准备master镜像
下载MySQL官方Docker镜像文件,并解压
# wget https://codeload.github.com/docker-library/mysql/zip/master# unzip master# mkdir /home/lipuan/mysqlDockerFile# cp -Rf mysql-master/5.7/Dockerfile /home/lipuan/mysqlDockerFile# cp -Rf mysql-master/5.7/docker-entrypoint.sh /home/lipuan/mysqlDockerFile# rm -rf mysql-master# chmod +x docker-entrypoint.sh
Dockerfile中添加,位置如下图所示
RUN sed -i '/\[mysqld\]/a server-id=1\nlog-bin' /etc/mysql/mysql.conf.d/mysqld.cnf
Dockerfile-master
docker-entrypoint.sh中添加,位置如下图所示
echo "CREATE USER '$MYSQL_REPLICATION_USER'@'%' IDENTIFIED BY '$MYSQL_REPLICATION_PASSWORD' ;" | "${mysql[@]}"echo "GRANT REPLICATION SLAVE ON *.* TO '$MYSQL_REPLICATION_USER'@'%' IDENTIFIED BY '$MYSQL_REPLICATION_PASSWORD' ;" | "${mysql[@]}"echo 'FLUSH PRIVILEGES ;' | "${mysql[@]}"
entrypoint-master
准备slave的镜像
下载MySQL官方Docker镜像文件
# wget https://codeload.github.com/docker-library/mysql/zip/master# unzip master# mkdir /home/lipuan/mysqlDockerFile# cd ~# cp -Rf mysql-master/5.7/Dockerfile /home/lipuan/mysqlDockerFile# cp -Rf mysql-master/5.7/docker-entrypoint.sh /home/lipuan/mysqlDockerFile# rm -rf mysql-master# chmod +x docker-entrypoint.sh
Dockerfile中添加,位置如下图所示
RUN RAND="$(date +%s | rev | cut -c 1-2)$(echo ${RANDOM})" && sed -i '/\[mysqld\]/a server-id='$RAND'\nlog-bin' /etc/mysql/mysql.conf.d/mysqld.cnf
此处server-id用的是随机数
Dockerfile-slave
2.3 docker-entrypoint.sh中添加,位置如下图所示
echo "STOP SLAVE;" | "${mysql[@]}"echo "CHANGE MASTER TO master_host='$MYSQL_MASTER_SERVICE_HOST', master_user='$MYSQL_REPLICATION_USER', master_password='$MYSQL_REPLICATION_PASSWORD' ;" | "${mysql[@]}"echo "START SLAVE;" | "${mysql[@]}"
slave配置中,master_host一项用的是$MYSQL_MASTER_SERVICE_HOST,这个环境变量(enviromnent variable)是由k8s生成的。
entrypoint-slave.png
构建master镜像
# cd /home/lipuan/mysqlDockerFile/# docker build -t paulliu/mysql-master:0.1 .
构建slave镜像
# cd /home/lipuan/mysqlDockerFile/# docker build -t paulliu/mysql-slave:0.1 .
上传镜像
# docker login# docke push paulliu/mysql-master:0.1# docke push paulliu/mysql-slave:0.1
三、MySQL集群部署
# cd /home/lipuan/DockerBuild
此后内容若无指出均在此目录下执行此部分操作,所有yaml文件缩进空格必须严格,否则无法构建成功
新建mysql-service.yaml文件
# touch mysql-service.yaml
添加内容
apiVersion: v1 kind: Service metadata: name: mysql-master labels: app: mysql-master namespace: energy-prod spec: type: NodePort ports: - port: 3306 targetPort: 3306 nodePort: 8688 selector: app: mysql-master --- apiVersion: v1 kind: Service metadata: name: mysql-slave labels: app: mysql-slave namespace: energy-prod spec: type: NodePort ports: - port: 3306 targetPort: 3306 nodePort: 8689 selector: app: mysql-slave
新建mysql-statefulset.yaml文件
# touch mysql-statefulset.yaml
添加内容
apiVersion: apps/v1beta1 kind: StatefulSet metadata: name: mysql-master labels: name: mysql-master namespace: energy-prod spec: serviceName: mysql-master replicas: 1 template: metadata: labels: app: mysql-master spec: terminationGracePeriodSeconds: 10 containers: - name: mysql-master image: xxx.xxx.xxx.xxx/library/mysql-master:1.2 ports: - containerPort: 3306 env: - name: MYSQL_ROOT_PASSWORD value: "MySQL@lipuan.2018" - name: MYSQL_REPLICATION_USER value: "sync" - name: MYSQL_REPLICATION_PASSWORD value: "MySQL@lipuan.2018" volumeMounts: - name: mysql-master-v mountPath: /var/lib/mysql nodeSelector: nodetype: mysql-master volumes: - name: mysql-master-v hostPath: path: /data/mysql-master/data --- apiVersion: apps/v1beta1 kind: StatefulSet metadata: name: mysql-slave labels: name: mysql-master namespace: energy-prod spec: serviceName: mysql-slave replicas: 1 template: metadata: labels: app: mysql-slave spec: terminationGracePeriodSeconds: 10 containers: - name: mysql-slave image: xxx.xxx.xxx.xxx/library/mysql-slave:1.2 ports: - containerPort: 3306 env: - name: MYSQL_ROOT_PASSWORD value: "MySQL@lipuan.2018" - name: MYSQL_REPLICATION_USER value: "sync" - name: MYSQL_REPLICATION_PASSWORD value: "MySQL@lipuan.2018" volumeMounts: - name: mysql-slave-v mountPath: /var/lib/mysql nodeSelector: nodetype: mysql-slave volumes: - name: mysql-slave-v hostPath: path: /data/mysql-slave/data
部署MySQL master服务
# kubectl create -f mysql-service.yaml# kubectl create -f mysql-statefulset.yaml
查看运行情况
# kubectl get pods,service,rc
写在文末
写到这里基于Kubernetes的MySQL主从集群就搭建成功了,如果有哪位朋友对于其中步骤不是很清楚,欢迎互相学习。
本文是笔者首次写技术博客,如有错漏等问题,还望各位大大指出批评!
作者:lipuan
链接:https://www.jianshu.com/p/da0b339e1274
共同学习,写下你的评论
评论加载中...
作者其他优质文章