【k8s】Kubernetes存储之使用 StatefulSet 部署 MySQL 主从集群

本文主要是介绍【k8s】Kubernetes存储之使用 StatefulSet 部署 MySQL 主从集群，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

一、部署原理

官方文档
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二、部署 MySQL

Kubernetes 的集群：
master：server2
node：server3、server4

01_ 一个 ConfigMap

创建目录：
/root/volumes/StatefulSet/mysql/
cd /root/volumes/StatefulSet/mysql
创建cm：

# configMap.yml 
apiVersion: v1
kind: ConfigMap
metadata:name: mysqllabels:app: mysql
data:master.cnf: |# Apply this config only on the master.[mysqld]log-bin    slave.cnf: |# Apply this config only on slaves.[mysqld]super-read-only

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02_两个 Service

master端安装MySQL：
yum install mariadb -y
创建service：
Headless Service（无头服务）
MySQL客户端服务

apiVersion: v1
kind: Service
metadata:name: mysqllabels:app: mysql
spec:ports:- name: mysqlport: 3306clusterIP: Noneselector:app: mysql
---
apiVersion: v1
kind: Service
metadata:name: mysql-readlabels:app: mysql
spec:ports:- name: mysqlport: 3306selector:app: mysql

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03_一个 StatefulSet

所需镜像：（可以提前拉取到Harbor仓库，创建）

mysql:5.7
xtrabackup:1.0（参考镜像 ist0ne/xtrabackup:1.0）

kubectl apply -f statefulset.yml

# statefulset.yml
apiVersion: apps/v1
kind: StatefulSet
metadata:name: mysql
spec:selector:matchLabels:app: mysqlserviceName: mysqlreplicas: 3template:metadata:labels:app: mysqlspec:initContainers:- name: init-mysqlimage: mysql:5.7command:- bash- "-c"- |set -ex# Generate mysql server-id from pod ordinal index.[[ `hostname` =~ -([0-9]+)$ ]] || exit 1ordinal=${BASH_REMATCH[1]}echo [mysqld] > /mnt/conf.d/server-id.cnf# Add an offset to avoid reserved server-id=0 value.echo server-id=$((100 + $ordinal)) >> /mnt/conf.d/server-id.cnf# Copy appropriate conf.d files from config-map to emptyDir.if [[ $ordinal -eq 0 ]]; thencp /mnt/config-map/master.cnf /mnt/conf.d/elsecp /mnt/config-map/slave.cnf /mnt/conf.d/fi          volumeMounts:- name: confmountPath: /mnt/conf.d- name: config-mapmountPath: /mnt/config-map- name: clone-mysqlimage: xtrabackup:1.0command:- bash- "-c"- |set -ex# Skip the clone if data already exists.[[ -d /var/lib/mysql/mysql ]] && exit 0# Skip the clone on master (ordinal index 0).[[ `hostname` =~ -([0-9]+)$ ]] || exit 1ordinal=${BASH_REMATCH[1]}[[ $ordinal -eq 0 ]] && exit 0# Clone data from previous peer.ncat --recv-only mysql-$(($ordinal-1)).mysql 3307 | xbstream -x -C /var/lib/mysql# Prepare the backup.xtrabackup --prepare --target-dir=/var/lib/mysql          volumeMounts:- name: datamountPath: /var/lib/mysqlsubPath: mysql- name: confmountPath: /etc/mysql/conf.dcontainers:- name: mysqlimage: mysql:5.7env:- name: MYSQL_ALLOW_EMPTY_PASSWORDvalue: "1"ports:- name: mysqlcontainerPort: 3306volumeMounts:- name: datamountPath: /var/lib/mysqlsubPath: mysql- name: confmountPath: /etc/mysql/conf.dresources:requests:cpu: 500mmemory: 512MilivenessProbe:exec:command: ["mysqladmin", "ping"]initialDelaySeconds: 30periodSeconds: 10timeoutSeconds: 5readinessProbe:exec:# Check we can execute queries over TCP (skip-networking is off).command: ["mysql", "-h", "127.0.0.1", "-e", "SELECT 1"]initialDelaySeconds: 5periodSeconds: 2timeoutSeconds: 1      - name: xtrabackupimage: xtrabackup:1.0ports:- name: xtrabackupcontainerPort: 3307command:- bash- "-c"- |set -excd /var/lib/mysql# Determine binlog position of cloned data, if any.if [[ -f xtrabackup_slave_info && "x$(<xtrabackup_slave_info)" != "x" ]]; then# XtraBackup already generated a partial "CHANGE MASTER TO" query# because we're cloning from an existing slave. (Need to remove the tailing semicolon!)cat xtrabackup_slave_info | sed -E 's/;$//g' > change_master_to.sql.in# Ignore xtrabackup_binlog_info in this case (it's useless).rm -f xtrabackup_slave_info xtrabackup_binlog_infoelif [[ -f xtrabackup_binlog_info ]]; then# We're cloning directly from master. Parse binlog position.[[ `cat xtrabackup_binlog_info` =~ ^(.*?)[[:space:]]+(.*?)$ ]] || exit 1rm -f xtrabackup_binlog_info xtrabackup_slave_infoecho "CHANGE MASTER TO MASTER_LOG_FILE='${BASH_REMATCH[1]}',\MASTER_LOG_POS=${BASH_REMATCH[2]}" > change_master_to.sql.infi# Check if we need to complete a clone by starting replication.if [[ -f change_master_to.sql.in ]]; thenecho "Waiting for mysqld to be ready (accepting connections)"until mysql -h 127.0.0.1 -e "SELECT 1"; do sleep 1; doneecho "Initializing replication from clone position"mysql -h 127.0.0.1 \-e "$(<change_master_to.sql.in), \MASTER_HOST='mysql-0.mysql', \MASTER_USER='root', \MASTER_PASSWORD='', \MASTER_CONNECT_RETRY=10; \START SLAVE;" || exit 1# In case of container restart, attempt this at-most-once.mv change_master_to.sql.in change_master_to.sql.origfi# Start a server to send backups when requested by peers.exec ncat --listen --keep-open --send-only --max-conns=1 3307 -c \"xtrabackup --backup --slave-info --stream=xbstream --host=127.0.0.1 --user=root"          volumeMounts:- name: datamountPath: /var/lib/mysqlsubPath: mysql- name: confmountPath: /etc/mysql/conf.dresources:requests:cpu: 100mmemory: 100Mivolumes:- name: confemptyDir: {}- name: config-mapconfigMap:name: mysqlvolumeClaimTemplates:- metadata:name: dataspec:accessModes: ["ReadWriteOnce"]resources:requests:storage: 5Gi