K8S学习之volume

hostPath

hostPath类型的存储卷是指将工作节点上某文件系统的目录或文件挂载于Pod中的一种存储卷。把宿主机上的目录挂载到容器，但是在每个节点上都要有，因为不确定容器会分配到哪个节点。也是把存储从宿主机挂载到k8s集群上，但它有许多限制，例如只支持单节点（Node），而且只支持“ReadWriteOnce”模式。

指定node节点

kubectl label nodes k8s-node01 mariadb=mariadb 

查看node节点label值 
kubectl get nodes --show-labels

挂载卷

语法： 
1. volumeMounts为containers下级key，containers.volumeMounts。volumes与 containers平级。 
2. containers.volumeMounts.name与volumes.name值一致。 
3. containers.volumeMounts.mountPath是容器内目录 
4. volumes.hostPath.path是宿主机挂载目录 
5. volumes.hostPath.type值必须为"Directory" 

containers 
  volumeMounts: 
    - mountPath: /var/lib/mysql 
      name: mariadb-volume 
  ....... 
volumes: 
  - name: mariadb-volume 
    hostPath: 
      path: /data/mariadb 
      type: Directory 

例如： 
volumeMounts: 
  - mountPath: /var/lib/mysql 
    name: mariadb-volume 
restartPolicy: Always
volumes: 
  - name: mariadb-volume 
    hostPath: 
      path: /data/mariadb 
      type: Directory

全部资源文件清单

labels/mariadbsecret.yml

apiVersion: v1 
kind: Secret 
metadata: 
  name: mariadbsecret 
type: Opaque 
data: 
  password: YWRtaW4=

labels/mariadb.yml

apiVersion: apps/v1 
kind: Deployment 
metadata: 
  name: mariadb-deploy 
  labels: 
    app: mariadb-deploy 
spec: 
  replicas: 1 
  template: 
    metadata: 
      name: mariadb-deploy 
      labels: 
        app: mariadb-deploy 
    spec: 
      nodeSelector: 
        mariadb: mariadb 
      imagePullSecrets: 
        - name: lagouharbor 
      containers: 
        - name: mariadb-deploy 
          image: 192.168.198.155:5000/lagouedu/mariadb:10.5.2 
          imagePullPolicy: IfNotPresent 
          ports: 
            - containerPort: 3307 
          env:
            - name: MYSQL_ROOT_PASSWORD 
              #这是mysqlroot用户的密码 
              valueFrom: 
                secretKeyRef: 
                  key: password 
                  name: mariadbsecret 
            - name: TZ 
              value: Asia/Shanghai 
            args: 
              - "--character-set-server=utf8mb4" 
              - "--collation-server=utf8mb4_unicode_ci" 
            volumeMounts: 
              - mountPath: /etc/mysql/mariadb.conf.d/ #容器内的挂载目录 
                name: lagoumariadb #随便给一个名字,这个名字必须与volumes.name一致 
              - mountPath: /var/lib/mysql #容器内的挂载目录 
                name: volume-mariadb 
          restartPolicy: Always 
          volumes: 
            - name: lagoumariadb 
              configMap: 
                name: mariadbconfigmap 
            - name: volume-mariadb 
              hostPath: 
                path: /data/mariadb 
                type: Directory 
  selector: 
    matchLabels: 
      app: mariadb-deploy 
--- 
apiVersion: v1 
kind: Service 
metadata: 
  name: mariadb-svc 
spec: 
  selector: 
    app: mariadb-deploy 
  ports: 
    - port: 3307 
      targetPort: 3307 
      nodePort: 30036 
  type: NodePort

labels/mariadbconfigmap.yml

apiVersion: v1 
data: 
  my.cnf: "省略中间数据部分，请各位同学前面章节" 
kind: ConfigMap 
metadata: 
  name: mariadbconfigmap

客户端测试

IP:192.168.198.157 
username:root 
password:admin 
prot: 30036

emptyDir

emptyDir存储卷是Pod生命周期中的一个临时目录，在pod对象被移除时会被一并删除，用得很少，例如同一pod内的多个容器间文件共享，或者作为容器数据的临时存储目录用于数据缓存系统等。同学们可以自行查找资料进行学习。