k8s 部署高可用mysql 主从集群

Posted 2021-12-28 李昊轩的博客

主从的cm
主从的svc , statefulset
都被我合并到一个文件里了,
应该是可以用的

注意修改storageclass的名称
注意apply的时候 -n 指定ns

#application/mysql/mysql-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: mysql
  labels:
    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
---
# application/mysql/mysql-services.yaml
# Headless service for stable DNS entries of StatefulSet members.
apiVersion: v1
kind: Service
metadata:
  name: mysql
  labels:
    app: mysql
spec:
  ports:
    - name: mysql
      port: 3306
  clusterIP: None
  selector:
    app: mysql
---
# Client service for connecting to any MySQL instance for reads.
# For writes, you must instead connect to the master: mysql-0.mysql.
apiVersion: v1
kind: Service
metadata:
  name: mysql-read
  labels:
    app: mysql
spec:
  ports:
    - name: mysql
      port: 3306
  selector:
    app: mysql
---
#application/mysql/mysql-statefulset.yaml
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: mysql
spec:
  selector:
    matchLabels:
      app: mysql
  serviceName: mysql
  replicas: 3
  template:
    metadata:
      labels:
        app: mysql
    spec:
      # 设置初始化容器，进行一些准备工作
      initContainers:
        - name: init-mysql
          image: mysql:5.7
          # 为每个MySQL节点配置service-id
          # 如果节点序号是0，则使用master的配置， 其余节点使用slave的配置
          command:
            - bash
            - "-c"
            - |
              set -ex
              # Generate mysql server-id from pod ordinal index.
              [[ `hostname` =~ -([0-9]+)$ ]] || exit 1
              ordinal=$BASH_REMATCH[1]
              echo [mysqld] > /mnt/conf.d/server-id.cnf
              # Add an offset to avoid reserved server-id=0 value.
              echo server-id=$((100 + $ordinal)) >> /mnt/conf.d/server-id.cnf
              # Copy appropriate conf.d files from config-map to emptyDir.
              if [[ $ordinal -eq 0 ]]; then
                cp /mnt/config-map/master.cnf /mnt/conf.d/
              else
                cp /mnt/config-map/slave.cnf /mnt/conf.d/
              fi
          volumeMounts:
            - name: conf
              mountPath: /mnt/conf.d
            - name: config-map
              mountPath: /mnt/config-map
        - name: clone-mysql
          image: yizhiyong/xtrabackup:latest
          # 为除了节点序号为0的主节点外的其它节点，备份前一个节点的数据
          command:
            - bash
            - "-c"
            - |
              set -ex
              # Skip the clone if data already exists.
              [[ -d /var/lib/mysql/mysql ]] && exit 0
              # Skip the clone on master (ordinal index 0).
              [[ `hostname` =~ -([0-9]+)$ ]] || exit 1
              ordinal=$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: data
              mountPath: /var/lib/mysql
              subPath: mysql
            - name: conf
              mountPath: /etc/mysql/conf.d
      containers:
        - name: mysql
          image: mysql:5.7
          # 设置支持免密登录
          env:
            - name: MYSQL_ALLOW_EMPTY_PASSWORD
              value: "1"
          ports:
            - name: mysql
              containerPort: 3306
          volumeMounts:
            - name: data
              mountPath: /var/lib/mysql
              subPath: mysql
            - name: conf
              mountPath: /etc/mysql/conf.d
          resources:
            # 设置启动pod需要的资源，官方文档上需要500m cpu，1Gi memory。
            # 我本地测试的时候，会因为资源不足，报1 Insufficient cpu, 1 Insufficient memory错误，所以我改小了点
            requests:
              # m是千分之一的意思，100m表示需要0.1个cpu
              cpu: 100m
              # Mi是兆的意思，需要100M 内存
              memory: 100Mi
          livenessProbe:
            # 使用mysqladmin ping命令，对MySQL节点进行探活检测
            # 在节点部署完30秒后开始，每10秒检测一次，超时时间为5秒
            exec:
              command: [ "mysqladmin", "ping" ]
            initialDelaySeconds: 30
            periodSeconds: 10
            timeoutSeconds: 5
          readinessProbe:
            # 对节点服务可用性进行检测， 启动5秒后开始，每2秒检测一次，超时时间1秒
            exec:
              # Check we can execute queries over TCP (skip-networking is off).
              command: [ "mysql", "-h", "127.0.0.1", "-e", "SELECT 1" ]
            initialDelaySeconds: 5
            periodSeconds: 2
            timeoutSeconds: 1
        - name: xtrabackup
          image: yizhiyong/xtrabackup:latest
          ports:
            - name: xtrabackup
              containerPort: 3307
          # 开始进行备份文件校验、解析和开始同步
          command:
            - bash
            - "-c"
            - |
              set -ex
              cd /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/;$//g' > change_master_to.sql.in
                # Ignore xtrabackup_binlog_info in this case (it's useless).
                rm -f xtrabackup_slave_info xtrabackup_binlog_info
              elif [[ -f xtrabackup_binlog_info ]]; then
                # We're cloning directly from master. Parse binlog position.
                [[ `cat xtrabackup_binlog_info` =~ ^(.*?)[[:space:]]+(.*?)$ ]] || exit 1
                rm -f xtrabackup_binlog_info xtrabackup_slave_info
                echo "CHANGE MASTER TO MASTER_LOG_FILE='$BASH_REMATCH[1]',\\
                      MASTER_LOG_POS=$BASH_REMATCH[2]" > change_master_to.sql.in
              fi
              # Check if we need to complete a clone by starting replication.
              if [[ -f change_master_to.sql.in ]]; then
                echo "Waiting for mysqld to be ready (accepting connections)"
                until mysql -h 127.0.0.1 -e "SELECT 1"; do sleep 1; done
                echo "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.orig
              fi
              # 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: data
              mountPath: /var/lib/mysql
              subPath: mysql
            - name: conf
              mountPath: /etc/mysql/conf.d
          resources:
            requests:
              cpu: 100m
              memory: 100Mi
      volumes:
        - name: conf
          emptyDir:  
        - name: config-map
          configMap:
            name: mysql
  # 设置PVC
  volumeClaimTemplates:
    - metadata:
        name: data
        annotations:
          volume.beta.kubernetes.io/storage-class: data-nfs-storage
      spec:
        storageClassName: data-nfs-storage
        accessModes: [ "ReadWriteOnce" ]
        resources:
          requests:
            storage: 1Gi