k8s-04-持久化存储

1.emptyDir类型

删除容器后数据会保存，但是删除pod后数据丢失

[root@k8s-master tomcat_demo]# cat mysql-rc.yml 
apiVersion: v1
kind: ReplicationController
metadata:
  name: mysql
  namespace: tomcat
spec:
  replicas: 1
  selector:
    app: mysql
  template:
    metadata:
      labels:
        app: mysql
    spec:
      volumes:  *
      - name: mysql  *
        emptyDir: {}  *
      containers:
        - name: mysql
          image: 10.0.0.11:5000/mysql:5.7
          volumeMounts:  *
          - name: mysql  *
            mountPath: /var/lib/mysql  *
          ports:
          - containerPort: 3306
          env:
          - name: MYSQL_ROOT_PASSWORD
            value: '123456'

2. HostPath类型

删除容器与删除pod，数据都会保存

[root@k8s-master tomcat_demo]# cat mysql-rc.yml 
apiVersion: v1
kind: ReplicationController
metadata:
  name: mysql
  namespace: tomcat
spec:
  replicas: 1
  selector:
    app: mysql
  template:
    metadata:
      labels:
        app: mysql
    spec:
      nodeName: 10.0.0.13  
      volumes:
      - name: mysql
        hostPath:  *
          path: /data/mysql  *
      containers:
        - name: mysql
          image: 10.0.0.11:5000/mysql:5.7
          volumeMounts:  *
          - name: mysql  *
            mountPath: /var/lib/mysql  *
          ports:
          - containerPort: 3306
          env:
          - name: MYSQL_ROOT_PASSWORD
            value: '123456'

3.nfs类型

[root@k8s-master tomcat_demo]# cat mysql-rc.yml
apiVersion: v1
kind: ReplicationController
metadata:
  name: mysql
  namespace: tomcat
spec:
  replicas: 1
  selector:
    app: mysql
  template:
    metadata:
      labels:
        app: mysql
    spec:
      nodeName: 10.0.0.13
      volumes:
      - name: mysql
        nfs:  *
          path: /data/tomcat-db  *
          server: 10.0.0.11  *
      containers:
        - name: mysql
          image: 10.0.0.11:5000/mysql:5.7
          volumeMounts:  *
          - name: mysql  *
            mountPath: /var/lib/mysql  *
          ports:
          - containerPort: 3306
          env:
          - name: MYSQL_ROOT_PASSWORD
            value: '123456'

4.分布式存储glusterfs

Glusterfs是一个开源分布式文件系统，具有强大的横向扩展能力，可支持数PB存储容量和数千客户端，通过网络互联成一个并行的网络文件系统。具有可扩展性、高性能、高可用性等特点

1.安装glusterfs

• 所有节点：

yum install  centos-release-gluster -y
yum install  install glusterfs-server -y
systemctl start glusterd.service
systemctl enable glusterd.service

• 为gluster集群增加存储单元brick

mkdir -p /gfs/test1
mkdir -p /gfs/test2
mkdir -p /gfs/test3

2.添加存储资源池

master节点：
gluster peer probe k8s-node1
gluster peer probe k8s-node2
gluster pool list

3.glusterfs卷管理

• 创建分布式复制卷
  gluster volume create dddd replica 2 k8s-master:/gfs/test1 k8s-node-1:/gfs/test1 k8s-master:/gfs/test2 k8s-node-1:/gfs/test2 force
• 启动卷
  gluster volume start dddd
• 查看卷
  gluster volume info dddd
• 挂载卷
  mount -t glusterfs 10.0.0.11:/dddd /mnt

4.添加分布式复制卷

gluster volume add-brick oldxu replica 2 k8s-master:/gfs/test2 k8s-node-1:/gfs/test2 k8s-node-2:/gfs/test2 force

5.扩容

gluster volume add-brick oldxu k8s-master:/gfs/test3 k8s-node-1:/gfs/test3 force

6.k8s 对接glusterfs存储

glusterfs对接需要创建endpoints和service

• 创建endpoints

vi  glusterfs-ep.yaml
iapiVersion: v1
kind: Endpoints
metadata:
  name: glusterfs
  namespace: tomcat
subsets:
- addresses:
  - ip: 10.0.0.11
  - ip: 10.0.0.12
  - ip: 10.0.0.13
  ports:
  - port: 49152
    protocol: TCP

• 创建service

vi  glusterfs-svc.yaml
iapiVersion: v1
kind: Service
metadata:
  name: glusterfs
  namespace: tomcat
spec:
  ports:
  - port: 49152
    protocol: TCP
    targetPort: 49152
  sessionAffinity: None
  type: ClusterIP

endpoints和service关联只需要name跟namespace相同

• 修改mysql的rc文件
  path为创建的卷名

  
  image.png

5.k8s映射外部服务

把外部的服务，通过svc和endpoint映射到k8s内部
不再创建mysql-rc，创建endpoint链接外端数据库

• 编写endpoint文件

[root@k8s-master wordpress]# cat mysql-ep.yaml
apiVersion: v1
kind: Endpoints
metadata:
  name: mysql-wp
  namespace: wordpress
subsets:
- addresses:
  - ip: 10.0.0.12
  ports:
  - port: 3306
    protocol: TCP


[root@k8s-master wordpress]# cat mysql-svc.yml 
apiVersion: v1
kind: Service
metadata:
  namespace: wordpress
  name: mysql-wp
spec:
  ports:
    - port: 3306
      targetPort: 3306

• 在12节点创建数据库
  yum install -y mariadb-server
systemctl start mariadb
create database wordpress;
grant all on wordpress.* to wordpress@'%' identified by 'wordpress';
• 启动
  kubectl create namespace wordpress
kubectl create -f .

6.pv和pvc

全局资源：所有namespace都能看见的资源 node、naspace、pv
局部资源：只属于某一个namespace下的资源 pod、rc、dashdoard、pvc ~ ~ ~
管理员创建pv，pvc使用资源

• 创建两个pv

[root@k8s-master pv_pvc]# cat mysql_pv.yaml 
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv1
  labels:
    type: nfs
spec:
  capacity:
    storage: 10Gi 
  accessModes:
    - ReadWriteMany 
  persistentVolumeReclaimPolicy: Recycle
  nfs:
    path: "/data/pv1"
    server: 10.0.0.11


[root@k8s-master pv_pvc]# cat mysql_pv2.yaml 
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv2
  labels:
    type: nfs
spec:
  capacity:
    storage: 30Gi 
  accessModes:
    - ReadWriteMany 
  persistentVolumeReclaimPolicy: Recycle
  nfs:
    path: "/data/pv2"
    server: 10.0.0.11

• 创建pvc

[root@k8s-master pv_pvc]# cat mysql_pvc.yaml 
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: pvc1
  namespace: tomcat
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 20Gi

创建的pvc为20G，会在pv1上使用

image.png

• 指定存储类型为pvc

    spec:
      nodeName: 10.0.0.13
      volumes:
      - name: mysql
        persistentVolumeClaim:
          claimName: pvc1