k8s安装集群版mysql以及遇到的坑

逃离我推掉我的手 2022-12-11 01:30 1549阅读 0赞

参考：  
[https://kubernetes.io/zh/docs/concepts/storage/storage-classes/][https_kubernetes.io_zh_docs_concepts_storage_storage-classes]  
[https://kubernetes.io/docs/tasks/run-application/run-replicated-stateful-application/][https_kubernetes.io_docs_tasks_run-application_run-replicated-stateful-application]  
[https://github.com/kubernetes-retired/external-storage/tree/master/nfs][https_github.com_kubernetes-retired_external-storage_tree_master_nfs]  
[https://www.jianshu.com/p/65ed4bdf0e89][https_www.jianshu.com_p_65ed4bdf0e89]  
[https://www.cnblogs.com/panwenbin-logs/p/12196286.html][https_www.cnblogs.com_panwenbin-logs_p_12196286.html]

## 遇到的错误 ##

### 1，3 pod has unbound immediate PersistentVolumeClaims. ###

根据官网安装mysql,需要PersistentVolumeClaim，不然会报3 pod has unbound immediate PersistentVolumeClaims:

## 2，mysql Back-off restarting failed container ##

这个原因有很多，比如k8s gcr.io被墙导致ImagePullBackOff，或者节点内存不足导致caused "process\_linux.go:101: executing setns process caused "exit status 1， 等。

如果k8s gcr.io被墙导致ImagePullBackOff，可以通过以下命令拉去镜像。

docker pull ist0ne/xtrabackup
    docker tag ist0ne/xtrabackup:latest gcr.io/google-samples/xtrabackup:1.0

注意如果是云集群，那个每个节点都要执行以上命令拉去镜像。

## 3，chown: changing ownership of ‘/var/lib/mysql/’: Operation not permitted ##

这个是由nfs的权限设置导致的。具体解决办法见NFS安装步骤–主节点执行。

## 安装步骤 ##

*  ### 一、环境准备–NFS ###

我的k8s有三个节点，一个master，两个node分别是以下三个。
    192.168.0.11  k8s-master
    192.168.0.22  k8s-node1
    192.168.0.33  k8s-node2

#### 1，主节点执行 ####

yum -y install nfs-utils rpcbind
    mkdir -p /home/nfs
    vi /etc/exports
    #加入,注意加入no_root_squash，这个是放开root权限，不加的话会报chown: changing ownership of '/var/lib/mysql/': Operation not permitted错误。
    /home/nfs *(insecure,rw,async,no_root_squash)
    
    #启动并设置开机启动
    systemctl start rpcbind.service
    systemctl status rpcbind.service
    systemctl enable rpcbind.service
    
    systemctl start nfs.service
    systemctl enable nfs.service
    systemctl status nfs.service

#### 2，node节点验证nfs可用 ####

yum -y intall nfs-utils 
    showmount -e 192.1681.0.11
    # 挂载至本地/mnt目录
    mount -t nfs 192.1681.0.11:/home/nfs /mnt 
    df -h
    umount /mnt

*  ### 二、配置PersistentVolumeClaims ###

#### 1,配置account并配置相关权限（rabc.yaml）,并使用 kubectl apply -f rabc.yaml执行，该文件主要设置nfs相关角色、权限信息。 ####

# rabc.yaml
    apiVersion: v1
    kind: ServiceAccount
    metadata:
      name: nfs-client-provisioner
      # replace with namespace where provisioner is deployed
      namespace: default        #根据实际环境设定namespace,下面类同
    ---
    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
        # replace with namespace where provisioner is deployed
        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
        # replace with namespace where provisioner is deployed
      namespace: default
    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

#### 2，创建StorageClass，并使用 kubectl apply -f storage-class.yaml执行， ####

# storage-class.yaml
    apiVersion: storage.k8s.io/v1
    kind: StorageClass
    metadata:
      name:  managed-nfs-storag
    provisioner: nfs  #这里的名称要和provisioner配置文件中的环境变量PROVISIONER_NAME保持一致
    parameters:
      type: gp2
    reclaimPolicy: Retain
    allowVolumeExpansion: true
    mountOptions:
      - debug
    volumeBindingMode: Immediate

#### 3，创建provisioner,并使用 kubectl apply -f nfs-provisioner.yaml执行 ####

# nfs-provisioner.yaml
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: nfs-client-provisioner
      labels:
        app: nfs-client-provisioner
      # replace with namespace where provisioner is deployed
      namespace: default  #与RBAC文件中的namespace保持一致
    spec:
      replicas: 1
      selector:
        matchLabels:
          app: nfs-client-provisioner
      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: quay.io/external_storage/nfs-client-provisioner:latest
              volumeMounts:
                - name: nfs-client-root
                  mountPath: /persistentvolumes
              env:
                - name: PROVISIONER_NAME
                  value: nfs  #provisioner名称,请确保该名称与 nfs-StorageClass.yaml文件中的provisioner名称保持一致
                - name: NFS_SERVER
                  value: 192.168.0.11   #NFS Server IP地址
                - name: NFS_PATH  
                  value: /home/nfs    #NFS挂载卷
          volumes:
            - name: nfs-client-root
              nfs:
                server: 192.168.0.11  #NFS Server IP地址
                path: /home/nfs     #NFS 挂载卷

#### 4，创建PersistentVolumeClaim，,并使用 kubectl apply -f nfs-pvc.yaml执行 ####

# pvc-nfs.yaml
    apiVersion: v1
    kind: PersistentVolumeClaim
    metadata:
      name: data
    spec:
      accessModes:
        - ReadWriteOnce
      volumeMode: Filesystem
      resources:
        requests:
          storage: 8Gi
      storageClassName:  managed-nfs-storag

*  ### 三、创建mysql集群 ###

#### 1，创建mysql-configmap，该文件主要是mysql的配置信息，这里设置mysql主节点与子节点的读写策略。 ####

# mysql-configmap.yaml
    kind: ConfigMap
    apiVersion: v1
    metadata:
      name: mysql
      namespace: default
      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

#### 2，创建mysql-services.yaml ####

apiVersion: v1
    kind: Service
    metadata:
      name: mysql
      labels:
        app: mysql
    spec:
      ports:
      - name: mysql
        port: 3306
      clusterIP: None
      selector:
        app: mysql
    ---
    apiVersion: v1
    kind: Service
    metadata:
      name: mysql-read
      labels: 
        app: mysql
    spec:
      ports:
      - name: mysql
        port: 3306
      selector:
        app: mysql

#### 3,创建mysql-statefulset.yaml ####

kind: StatefulSet
    apiVersion: apps/v1
    metadata:
      name: mysql
      namespace: default
    spec:
      replicas: 3
      selector:
        matchLabels:
          app: mysql
      template:
        metadata:
          creationTimestamp: null
          labels:
            app: mysql
        spec:
          volumes:
            - name: conf
              emptyDir: {}
            - name: config-map
              configMap:
                name: mysql
                defaultMode: 420
          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
              resources: {}
              volumeMounts:
                - name: conf
                  mountPath: /mnt/conf.d
                - name: config-map
                  mountPath: /mnt/config-map
              terminationMessagePath: /dev/termination-log
              terminationMessagePolicy: File
              imagePullPolicy: IfNotPresent
            - name: clone-mysql
              image: 'gcr.io/google-samples/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
              resources: {}
              volumeMounts:
                - name: nfs-pvc
                  mountPath: /var/lib/mysql
                  subPath: mysql
                - name: conf
                  mountPath: /etc/mysql/conf.d
              terminationMessagePath: /dev/termination-log
              terminationMessagePolicy: File
              imagePullPolicy: IfNotPresent
          containers:
            - name: mysql
              image: 'mysql:5.7'
              ports:
                - name: mysql
                  containerPort: 3306
                  protocol: TCP
              env:
                - name: MYSQL_ALLOW_EMPTY_PASSWORD
                  value: '1'
              resources:
                requests:
                  cpu: 50m
                  memory: 50Mi
              volumeMounts:
                - name: nfs-pvc
                  mountPath: /var/lib/mysql
                  subPath: mysql
                - name: conf
                  mountPath: /etc/mysql/conf.d
              livenessProbe:
                exec:
                  command:
                    - mysqladmin
                    - ping
                initialDelaySeconds: 30
                timeoutSeconds: 5
                periodSeconds: 10
                successThreshold: 1
                failureThreshold: 3
              readinessProbe:
                exec:
                  command:
                    - mysql
                    - '-h'
                    - 127.0.0.1
                    - '-e'
                    - SELECT 1
                initialDelaySeconds: 5
                timeoutSeconds: 1
                periodSeconds: 2
                successThreshold: 1
                failureThreshold: 3
              terminationMessagePath: /dev/termination-log
              terminationMessagePolicy: File
              imagePullPolicy: IfNotPresent
            - name: xtrabackup
              image: 'gcr.io/google-samples/xtrabackup:1.0'
              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"
                  tail -f /dev/null
              ports:
                - name: xtrabackup
                  containerPort: 3307
                  protocol: TCP
              resources:
                requests:
                  cpu: 50m
                  memory: 50Mi
              volumeMounts:
                - name: nfs-pvc
                  mountPath: /var/lib/mysql
                  subPath: mysql
                - name: conf
                  mountPath: /etc/mysql/conf.d
              terminationMessagePath: /dev/termination-log
              terminationMessagePolicy: File
              imagePullPolicy: IfNotPresent
          restartPolicy: Always
          terminationGracePeriodSeconds: 30
          dnsPolicy: ClusterFirst
          securityContext: {}
          schedulerName: default-scheduler
      volumeClaimTemplates:
        - kind: PersistentVolumeClaim
          apiVersion: v1
          metadata:
            name: nfs-pvc
            creationTimestamp: null
          spec:
            accessModes:
              - ReadWriteMany
            resources:
              requests:
                storage: 1Mi
            storageClassName: managed-nfs-storage
            volumeMode: Filesystem
          status:
            phase: Pending

[https_kubernetes.io_zh_docs_concepts_storage_storage-classes]: https://kubernetes.io/zh/docs/concepts/storage/storage-classes/
[https_kubernetes.io_docs_tasks_run-application_run-replicated-stateful-application]: https://kubernetes.io/docs/tasks/run-application/run-replicated-stateful-application/
[https_github.com_kubernetes-retired_external-storage_tree_master_nfs]: https://github.com/kubernetes-retired/external-storage/tree/master/nfs
[https_www.jianshu.com_p_65ed4bdf0e89]: https://www.jianshu.com/p/65ed4bdf0e89
[https_www.cnblogs.com_panwenbin-logs_p_12196286.html]: https://www.cnblogs.com/panwenbin-logs/p/12196286.html