源于K8S的StatefulSet部署MySQL集群
发布时间：2021-11-23 14:11:02 所属栏目：系统 来源：互联网
导读：展示如何使用 StatefulSet 控制器运行一个有状态的应用程序。此例是多副本的 MySQL 数据库。 示例应用的拓扑结构有一个主服务器和多个副本，使用异步的基于行(Row-Based) 的数据复制。 基于K8S的StatefulSet部署MySQL集群 搭建一个主从复制(Maser-Slave Repli
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展示如何使用 StatefulSet 控制器运行一个有状态的应用程序。此例是多副本的 MySQL 数据库。 示例应用的拓扑结构有一个主服务器和多个副本，使用异步的基于行(Row-Based) 的数据复制。 基于K8S的StatefulSet部署MySQL集群 搭建一个“主从复制”(Maser-Slave Replication)的 MySQL 集群 存在一个主节点【master】，有多个从节点【slave】 从节点可以水平拓展 所有的写操作，只能在主节点上执行 读操作可以在所有节点上执行 一、部署NFS服务器 #服务器安装nfs服务，提供nfs存储功能 1、安装nfs-utils yum install nfs-utils (centos) 或者 apt-get install nfs-kernel-server (ubuntu) 2、启动服务 systemctl enable nfs-server systemctl start nfs-server 3、创建共享目录完成共享配置 mkdir /home/nfs #创建共享目录 4、编辑共享配置 vim /etc/exports #语法格式： 共享文件路径 客户机地址（权限） #这里的客户机地址可以是IP,网段，域名,也可以是任意* /home/nfs *(rw,async,no_root_squash) #服务器安装nfs服务，提供nfs存储功能 1、安装nfs-utils yum install nfs-utils (centos) 或者 apt-get install nfs-kernel-server (ubuntu) 2、启动服务 systemctl enable nfs-server systemctl start nfs-server 3、创建共享目录完成共享配置 mkdir /home/nfs #创建共享目录 4、编辑共享配置 vim /etc/exports #语法格式： 共享文件路径 客户机地址（权限） #这里的客户机地址可以是IP,网段，域名,也可以是任意* /home/nfs *(rw,async,no_root_squash) 服务自检命令 exportfs -arv 5、重启服务 systemctl restart nfs-server 6、本机查看nfs 共享目录 #showmount -e 服务器IP地址 (如果提示命令不存在，则需要yum install showmount) showmount -e 127.0.0.1 /home/nfs * 7、客户端模拟挂载[所有k8s的节点都需要安装客户端] [root@master-1 ~]# yum install nfs-utils （centos） 或者 apt-get install nfs-common （ubuntu） [root@master-1 ~]# mkdir /test [root@master-1 ~]# mount -t nfs 172.16.201.209:/home/nfs /test #取消挂载 [root@master-1 ~]# umount /test 二、配置PV 动态供给(NFS StorageClass)，创建pvc 部署NFS实现自动创建PV插件： 一共设计到4个yaml 文件 ，官方的文档有详细的说明 https://github.com/kubernetes-incubator/external-storage 基于K8S的StatefulSet部署MySQL集群 基于K8S的StatefulSet部署MySQL集群 root@k8s-master1:~ # mkdir /root/pvc root@k8s-master1:~ # cd /root/pvc 创建rbac.yaml 文件 root@k8s-master1:pvc # cat rbac.yaml kind: ServiceAccount apiVersion: v1 metadata: name: nfs-client-provisioner --- kind: ClusterRole apiVersion: rbac.authorization.k8s.io/v1 metadata: name: nfs-client-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: ["create", "update", "patch"] --- kind: ClusterRoleBinding apiVersion: rbac.authorization.k8s.io/v1 metadata: name: run-nfs-client-provisioner subjects: - kind: ServiceAccount name: nfs-client-provisioner namespace: default roleRef: kind: ClusterRole name: nfs-client-provisioner-runner apiGroup: rbac.authorization.k8s.io --- kind: Role apiVersion: rbac.authorization.k8s.io/v1 metadata: name: leader-locking-nfs-client-provisioner rules: - apiGroups: [""] resources: ["endpoints"] verbs: ["get", "list", "watch", "create", "update", "patch"] --- kind: RoleBinding apiVersion: rbac.authorization.k8s.io/v1 metadata: name: leader-locking-nfs-client-provisioner subjects: - kind: ServiceAccount name: nfs-client-provisioner # replace with namespace where provisioner is deployed namespace: default roleRef: kind: Role name: leader-locking-nfs-client-provisioner apiGroup: rbac.authorization.k8s.io 创建deployment.yaml 文件 官方默认的镜像地址，国内可能无法下载，可以使用 image: fxkjnj/nfs-client-provisioner:latest #定义NFS 服务器的地址，共享目录名称 root@k8s-master1:pvc # cat deployment.yaml apiVersion: v1 kind: ServiceAccount metadata: name: nfs-client-provisioner --- 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: serviceAccountName: nfs-client-provisioner containers: - name: nfs-client-provisioner image: fxkjnj/nfs-client-provisioner:latest volumeMounts: - name: nfs-client-root mountPath: /persistentvolumes env: - name: PROVISIONER_NAME value: fuseim.pri/ifs - name: NFS_SERVER value: 172.16.201.209 - name: NFS_PATH value: /home/nfs volumes: - name: nfs-client-root nfs: server: 172.16.201.209 path: /home/nfs 创建class.yaml root@k8s-master1:pvc # cat class.yaml apiVersion: storage.k8s.io/v1 kind: StorageClass metadata: name: managed-nfs-storage provisioner: fuseim.pri/ifs # or choose another name, must match deployment's env PROVISIONER_NAME' parameters: archiveOnDelete: "true" 部署 root@k8s-master1:pvc # kubectl apply -f . #查看存储卷 root@k8s-master1:pvc # kubectl get sc NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE managed-nfs-storage fuseim.pri/ifs Delete Immediate false 25h 三、编写mysql 相关yaml文件 MySQL 示例部署包含一个 ConfigMap、两个 Service 与一个 StatefulSet。 ConfigMap: vim 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 说明： 在这里，我们定义了 master.cnf 和 slave.cnf 两个 MySQL 的配置文件 master.cnf 开启了log-bin，可以使用二进制日志文件的方式进行主从复制. slave.cnf 开启了 super-read-only ，表示从节点只接受主节点的数据同步的所有写的操作，拒绝其他的写入操作，对于用户来说就是只读的 master.cnf 和 slave.cnf 已配置文件的形式挂载到容器的目录中 Service： vim 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 说明： clusterIP: None，使用无头服务 Headless Service(相比普通Service只是将spec.clusterIP定义为None，也就是没有clusterIP，直接使用endport 来通信)来维护Pod网络身份，会为每个Pod分配一个数字编号并且按照编号顺序部署。还需要在StatefulSet添加serviceName: “mysql”字段指定StatefulSet控制器 另外statefulset控制器网络标识，体现在主机名和Pod A记录： • 主机名：<statefulset名称>-<编号> 例如: mysql-0 • Pod DNS A记录：<statefulset名称-编号>.<service-name> .<namespace>.svc.cluster.local （POD 之间通过DNS A 记录互相通信） 例如: mysql-0.mysql.default.svc.cluster.local StatefulSet: vim 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: initContainers: - name: init-mysql image: 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 [[ $ordinal -eq 0 ]]; then cp /mnt/config-map/master.cnf /mnt/conf.d/ else cp /mnt/config-map/slave.cnf /mnt/conf.d/ fi volumeMounts: - name: conf mountPath: /mnt/conf.d - name: config-map mountPath: /mnt/config-map - name: clone-mysql image: fxkjnj/xtrabackup:1.0 command: - bash - "-c" - | set -ex # Skip the clone if data already exists. [[ -d /var/lib/mysql/mysql ]] && exit 0 # Skip the clone on master (ordinal index 0). [[ `hostname` =~ -([0-9]+)$ ]] || exit 1 ordinal=${BASH_REMATCH[1]} [[ $ordinal -eq 0 ]] && exit 0 # Clone data from previous peer. ncat --recv-only mysql-$(($ordinal-1)).mysql 3307 | xbstream -x -C /var/lib/mysql # Prepare the backup. xtrabackup --prepare --target-dir=/var/lib/mysql volumeMounts: - name: data mountPath: /var/lib/mysql subPath: mysql - name: conf mountPath: /etc/mysql/conf.d containers: - name: mysql image: mysql:5.7 env: - name: MYSQL_ALLOW_EMPTY_PASSWORD value: "1" ports: - name: mysql containerPort: 3306 volumeMounts: - name: data mountPath: /var/lib/mysql subPath: mysql - name: conf mountPath: /etc/mysql/conf.d resources: requests: cpu: 500m memory: 1Gi livenessProbe: exec: command: ["mysqladmin", "ping"] initialDelaySeconds: 30 periodSeconds: 10 timeoutSeconds: 5 readinessProbe: exec: # Check we can execute queries over TCP (skip-networking is off). command: ["mysql", "-h", "127.0.0.1", "-e", "SELECT 1"] initialDelaySeconds: 5 periodSeconds: 2 timeoutSeconds: 1 - name: xtrabackup image: fxkjnj/xtrabackup:1.0 ports: - name: xtrabackup containerPort: 3307 command: - bash - "-c" - | set -ex cd /var/lib/mysql # Determine binlog position of cloned data, if any. if [[ -f xtrabackup_slave_info && "x$(<xtrabackup_slave_info)" != "x" ]]; then # XtraBackup already generated a partial "CHANGE MASTER TO" query # because we're cloning from an existing 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 volumeClaimTemplates: - metadata: name: data spec: storageClassName: "managed-nfs-storage" accessModes: ["ReadWriteOnce"] resources: requests: storage: 0.5Gi 说明： 使用xtrbackup 工具进行容器初始化数据的备份，https://www.toutiao.com/i6999565563710292484 使用linux 自带的ncat 工具进行容器初始化数据的拷贝[使用ncat指令，远程地从前一个节点拷贝数据到本地] https://www.cnblogs.com/chengd/p/7565280.html 使用mysql的binlog 主从复制 来保证主从之间的数据一致 利用pod的主机名的序号来判断当前节点为主节点还是从节点，再根据对于节点拷贝不同的配置文件到指定位置 使用mysqladmin的ping 作为数据库的健康检测方式 使用nfs存储的 PV 动态供给(StorageClass)，持久化mysql的数据文件 四、部署并测试 root@k8s-master1:~/kubernetes/mysql# ll total 24 drwxr-xr-x 2 root root 4096 Nov 3 16:42 ./ drwxr-xr-x 8 root root 4096 Nov 3 13:33 ../ -rw-r--r-- 1 root root 278 Nov 2 22:15 mysql-configmap.yaml -rw-r--r-- 1 root root 556 Nov 2 22:08 mysql-services.yaml -rw-r--r-- 1 root root 5917 Nov 3 14:22 mysql-statefulset.yaml root@k8s-master1:~/kubernetes/mysql# kubectl apply -f . configmap/mysql create service/mysql create service/mysql-read create statefulset.apps/mysql create #动态追踪查看Pod的状态： root@k8s-master1:~/kubernetes/mysql# kubectl get pods -l app=mysql --watch NAME READY STATUS RESTARTS AGE mysql-0 2/2 Running 0 3h12m mysql-1 2/2 Running 0 3h11m mysql-2 2/2 Running 0 3h10m （编辑：武汉站长网） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |
