k8s部署mysql集群（statefulset）：主写从读、一主多从集群

本是古典何须时尚 2023-10-05 19:06 42阅读 0赞

## 安装nfs ##

### server和client端都执行 ###

yum install nfs-utils rpcbind -y
    systemctl start nfs
    systemctl start rpcbind
    systemctl enable nfs
    systemctl enable rpcbind

## 部署nfs-provisioner ##

### nfs-rbac.yaml ###

*  rbac鉴权
 *  设置nfs server
 *  设置nfs客户端与server端数据同步
    
     *  `mkdir -p /home/nfsmount && mount -t nfs 192.168.116.101:/nfs/data /home/nfsmount`

---
    apiVersion: v1
    kind: ServiceAccount
    metadata:
      name: nfs-provisioner
    ---
    kind: ClusterRole
    apiVersion: rbac.authorization.k8s.io/v1
    metadata:
       name: nfs-provisioner-runner
    rules:
       -  apiGroups: [""]
          resources: ["persistentvolumes"]
          verbs: ["get", "list", "watch", "create", "delete"]
       -  apiGroups: [""]
          resources: ["persistentvolumeclaims"]
          verbs: ["get", "list", "watch", "update"]
       -  apiGroups: ["storage.k8s.io"]
          resources: ["storageclasses"]
          verbs: ["get", "list", "watch"]
       -  apiGroups: [""]
          resources: ["events"]
          verbs: ["watch", "create", "update", "patch"]
       -  apiGroups: [""]
          resources: ["services", "endpoints"]
          verbs: ["get","create","list", "watch","update"]
       -  apiGroups: ["extensions"]
          resources: ["podsecuritypolicies"]
          resourceNames: ["nfs-provisioner"]
          verbs: ["use"]
    ---
    kind: ClusterRoleBinding
    apiVersion: rbac.authorization.k8s.io/v1
    metadata:
      name: run-nfs-provisioner
    subjects:
      - kind: ServiceAccount
        name: nfs-provisioner
        namespace: default
    roleRef:
      kind: ClusterRole
      name: nfs-provisioner-runner
      apiGroup: rbac.authorization.k8s.io
    ---
    #vi nfs-deployment.yaml；创建nfs-client的授权
    kind: Deployment
    apiVersion: apps/v1
    metadata:
       name: nfs-client-provisioner
    spec:
       replicas: 1
       strategy:
         type: Recreate
       selector:
         matchLabels:
            app: nfs-client-provisioner
       template:
          metadata:
             labels:
                app: nfs-client-provisioner
          spec:
             serviceAccount: nfs-provisioner
             containers:
                -  name: nfs-client-provisioner
                   image: 192.168.145.28:1603/kubesphere/nfs-client-provisioner:v3.1.0-k8s1.11
                   volumeMounts:
                     -  name: nfs-client-root
                        mountPath:  /persistentvolumes
                   env:
                     -  name: PROVISIONER_NAME #供应者的名字
                        value: storage.pri/nfs #名字虽然可以随便起，以后引用要一致
                     -  name: NFS_SERVER
                        value: 192.168.116.101
                     -  name: NFS_PATH
                        value: /nfs/data
             volumes:
               - name: nfs-client-root
                 nfs:
                   server: 192.168.116.101
                   path: /nfs/data

### storageclass-nfs.yaml ###

apiVersion: storage.k8s.io/v1
    kind: StorageClass
    metadata:
      name: storage-nfs
    provisioner: storage.pri/nfs
    reclaimPolicy: Delete

### 编写nfs-provisioner部署脚本 ###

*  部署nfs-provisioner
 *  设置为默认storageclass  
    `[root@m-1 kubesphere-install]# cat start.sh`

sudo kubectl apply -f nfs-rbac.yaml -f storageclass-nfs.yaml
    sudo kubectl patch storageclass storage-nfs -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"true"}}}'

## 部署mysql一主两从集群 ##

### mysql-all-in-one.yaml ###

apiVersion: v1
    kind: ConfigMap
    metadata:
      name: mysql-configmap
      namespace: dmgeo-lib
      labels:
        app: mysql
    data:
      primary.cnf: |
        # Apply this config only on the primary.
        [mysqld]
        log-bin
      replica.cnf: |
        # Apply this config only on replicas.
        [mysqld]
        super-read-only
    
    ---
    # Headless service for stable DNS entries of StatefulSet members.
    apiVersion: v1
    kind: Service
    metadata:
      name: mysql
      namespace: dmgeo-lib
      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 primary: mysql-0.mysql.
    apiVersion: v1
    kind: Service
    metadata:
      name: mysql-read
      namespace: dmgeo-lib
      labels:
        app: mysql
    spec:
      ports:
      - name: mysql
        port: 3306
      selector:
        app: mysql
    
    ---
    apiVersion: apps/v1
    kind: StatefulSet
    metadata:
      name: mysql
      namespace: dmgeo-lib
    spec:
      selector:
        matchLabels:
          app: mysql
      serviceName: mysql
      replicas: 3
      template:
        metadata:
          labels:
            app: mysql
        spec:
          initContainers:
          - name: init-mysql
            image: 192.168.145.28:1603/lego/mysql/mysql:5.7
            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 [[ $ordinal -eq 0 ]]; then
                cp /mnt/config-map/primary.cnf /mnt/conf.d/
              else
                cp /mnt/config-map/replica.cnf /mnt/conf.d/
              fi
            volumeMounts:
            - name: mysql-conf
              mountPath: /mnt/conf.d
            - name: mysql-configmap
              mountPath: /mnt/config-map
          - name: clone-mysql
            image: 192.168.145.28:1603/lego/mysql/twoeo/gcr.io-google-samples-xtrabackup:latest
            command:
            - bash
            - "-c"
            - |
              set -ex
              # Skip the clone if data already exists.
              [[ -d /var/lib/mysql/mysql ]] && exit 0
              # Skip the clone on primary (ordinal index 0).
              [[ `hostname` =~ -([0-9]+)$ ]] || 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: mysql-data
              mountPath: /var/lib/mysql
              subPath: mysql
            - name: mysql-conf
              mountPath: /etc/mysql/conf.d
          containers:
          - name: mysql
            image: 192.168.145.28:1603/lego/mysql/mysql:5.7
            env:
            - name: MYSQL_ROOT_PASSWORD
              value: 123456
            #- name: MYSQL_ALLOW_EMPTY_PASSWORD
            #  value: "1"
            ports:
            - name: mysql
              containerPort: 3306
            volumeMounts:
            - name: mysql-data
              mountPath: /var/lib/mysql
              subPath: mysql
            - name: mysql-conf
              mountPath: /etc/mysql/conf.d
            resources:
              requests:
                cpu: 500m
                memory: 1Gi
            livenessProbe:
              exec:
                command: ["mysqladmin", "ping"]
              initialDelaySeconds: 30
              periodSeconds: 10
              timeoutSeconds: 5
            readinessProbe:
              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: 192.168.145.28:1603/lego/mysql/twoeo/gcr.io-google-samples-xtrabackup:latest
            ports:
            - name: xtrabackup
              containerPort: 3307
            command:
            - bash
            - "-c"
            - |
              set -ex
              cd /var/lib/mysql
    
              # Determine binlog position of cloned data, if any.
              if [[ -f xtrabackup_slave_info && "x$(<xtrabackup_slave_info)" != "x" ]]; then
                # XtraBackup already generated a partial "CHANGE MASTER TO" query
                # because we're cloning from an existing replica. (Need to remove the tailing semicolon!)
                cat xtrabackup_slave_info | sed -E 's/;$//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 primary. 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: mysql-data
              mountPath: /var/lib/mysql
              subPath: mysql
            - name: mysql-conf
              mountPath: /etc/mysql/conf.d
            resources:
              requests:
                cpu: 100m
                memory: 100Mi
          volumes:
          - name: mysql-conf
            emptyDir: {
        }
          - name: mysql-configmap
            configMap:
              name: mysql-configmap
      volumeClaimTemplates:
      - metadata:
          name: mysql-data
        spec:
          accessModes: ["ReadWriteOnce"]
          resources:
            requests:
              storage: 10Gi

参考链接：  
[K8S 实战（六）| 配置 NFS 动态卷提供持久化存储][K8S _ _ NFS]  
[K8S 实战（七）| 有状态应用之 MySQL 集群][K8S _ _ MySQL]

[K8S _ _ NFS]: https://blog.zuolinux.com/2020/06/10/nfs-client-provisioner.html
[K8S _ _ MySQL]: http://blog.zuolinux.com/2020/06/15/statefulset-mysql-cluster.html