8、kubernetes之存储卷资源

梦里梦外; 2023-08-17 16:53 96阅读 0赞

### 一、存储卷的类型 ###

*  emptyDir：在宿主机上分一块内存空间给pod当做存储空间
 *  hostPath：在宿主机上分一块磁盘空间给pod当做存储空间
 *  网络存储：
    
     *  SAN：iSCSI，FC
     *  NAS：nfs，cifs
     *  分布式存储：glusterfs，rbd，cephfs，...
     *  云存储：EBS，Azure，Disk

# kubectl explain  pods.spec.volumes  #查看k8s支持的存储

### 二、emptyDir ###

apiVersion: v1
    kind: Pod
    metadata:
      name: pod-vol-demo
      namespace: default
      labels:
        app: myapp
        tier: frontend
      annotations:
        dongfei.tech/created-by: "cluster admin"
    spec:
      containers:
      - name: myapp
        image: dongfeimg/myapp:v1
        imagePullPolicy: IfNotPresent
        ports:
        - name: http
          containerPort: 80
        volumeMounts:
        - name: htmlvomumes
          mountPath: /data/web/html2/
      volumes:
        - name: htmlvomumes
          emptyDir: 
            medium: ""  #使用宿主机内存当做磁盘挂载
            sizeLimit: "1024"  #限制使用的内存

### 三、hostPath ###

apiVersion: v1
    kind: Pod
    metadata:
      name: pod-vol-hostpath
      namespace: default
    spec:
      containers:
      - name: myapp
        image: dongfeimg/myapp:v1
        volumeMounts:
        - name: html
          mountPath: /usr/share/nginx/html/
      volumes:
      - name: html
        hostPath:
          path: /data/pod/volume1  #node节点路径
          type: DirectoryOrCreate  #文件夹不存在则创建

### 四、nfs ###

*  搭建/测试nfs-server

# yum install nfs-utils -y
    # mkdir /data/volumes/
    # vim /etc/exports
    /data/volumes   192.168.100.0/24(rw,no_root_squash)
    # systemctl start nfs
    # systemctl enable nfs
    
    # mount -t nfs 192.168.100.1:/data/volumes /mnt/

apiVersion: v1
    kind: Pod
    metadata:
      name: pod-vol-nfs
      namespace: default
    spec:
      containers:
      - name: myapp
        image: dongfeimg/myapp:v1
        volumeMounts:
        - name: html
          mountPath: /usr/share/nginx/html/
      volumes:
      - name: html
        nfs:
          path: /data/volumes
          server: 192.168.100.1

### 五、pv和pvc ###

# kubectl explain pv
    # kubectl explain pvc
    # kubectl get pv
    # kubectl get pvc

#### 1、提前准备PV的方式 ####

*  准备存储空间

# mkdir -p /data/volumes/v{1,2,3,4,5}
    # vim /etc/exports
    /data/volumes/v1        192.168.100.0/24(rw,no_root_squash)
    /data/volumes/v2        192.168.100.0/24(rw,no_root_squash)
    /data/volumes/v3        192.168.100.0/24(rw,no_root_squash)
    /data/volumes/v4        192.168.100.0/24(rw,no_root_squash)
    /data/volumes/v5        192.168.100.0/24(rw,no_root_squash)
    # exportfs -arv
    # showmount -e

*  创建pv

访问模型（accessModes <\[\]string>）：[https://kubernetes.io/docs/concepts/storage/persistent-volumes/\#access-modes][https_kubernetes.io_docs_concepts_storage_persistent-volumes_access-modes]

apiVersion: v1
    kind: PersistentVolume
    metadata:
      name: pv001
      labels:
        name: pv001
    spec:
      nfs:
        path: /data/volumes/v1
        server: 192.168.100.1
      accessModes: ["ReadWriteMany","ReadWriteOnce"]
      capacity:
        storage: 3Gi
    ---
    apiVersion: v1
    kind: PersistentVolume
    metadata:
      name: pv002
      labels:
        name: pv002
    spec:
      nfs:
        path: /data/volumes/v2
        server: 192.168.100.1
      accessModes: ["ReadWriteOnce"]
      capacity:
        storage: 5Gi
    ---
    apiVersion: v1
    kind: PersistentVolume
    metadata:
      name: pv003
      labels:
        name: pv003
    spec:
      nfs:
        path: /data/volumes/v3
        server: 192.168.100.1
      accessModes: ["ReadWriteOnce"]
      capacity:
        storage: 50Gi

*  创建pvc

apiVersion: v1
    kind: PersistentVolumeClaim
    metadata:
      name: pvc001
      namespace: default
    spec:
      accessModes: ["ReadWriteOnce"]
      resources: 
        requests: 
          storage: 6Gi  #要求绑定大于6G的pv
    ---
    apiVersion: v1
    kind: Pod
    metadata:
      name: pod-vol-pvc
      namespace: default
    spec:
      containers:
      - name: myapp
        image: dongfeimg/myapp:v1
        volumeMounts:
        - name: html
          mountPath: /usr/share/nginx/html/
      volumes:
      - name: html
        persistentVolumeClaim:
          claimName: pvc001

#### 2、按pvc需要自动创建pv ####

*  需要支持resfull风格api的存储来请求动态创建存储，实现动态请求创建pv

### 六、configmap和secret ###

*  secret和configmap是两个特殊的存储卷，用于用户将集群外的配置注入pod
 *  secret和configmap的功能相同，configmap以明文存储，secret是用base64编码存放

> 配置容器化应用的方式：
> 
> 1.  自定义命令行参数：args: \[\]
> 2.  把配置文件直接copy进镜像
> 3.  环境变量加载配置
>     
>     1.  cloud native的应用程序一般可通过环境变量加载配置
>     2.  通过entrypoint脚本来预处理变量为配置文件中的配置信息
> 4.  存储卷

# kubectl explain cm

*  命令行直接创建cm

# kubectl create configmap nginx-config --from-literal=nginx_port=80 --from-literal=server_name=myapp.dongfei.tech
    # kubectl get cm
    # kubectl describe cm nginx-config

*  命令行创建secret

# kubectl create secret generic mysql-root-password --from-literal=password=My@Pass
    # kubectl get secret
    # kubectl describe secret mysql-root-password
    # kubectl get secret mysql-root-password -o yaml
    # echo TXlAUGFzcw== |base64 -d  #解码
    My@Pass

*  将配置文件创建为cm

# cat www.conf 
    server {
            server_name myapp.dongfei.tech;
            listen 80;
            root /data/web/html;
    }
    # kubectl create configmap nginx-www --from-file=./www.conf  #不指定key则将文件名当做key，文件内容当做value

*  将cm通过环境变量注入pod

apiVersion: v1
    kind: Pod
    metadata:
      name: pod-cm-1
      namespace: default
      labels:
        app: myapp
        tier: frontend
      annotations:
        dongfei.tech/created-by: "cluster admin"
    spec:
      containers:
      - name: myapp
        image: dongfeimg/myapp:v1
        imagePullPolicy: IfNotPresent
        ports:
        - name: http
          containerPort: 80
        env:
        - name: NGINX_SERVER_PORT
          valueFrom:
            configMapKeyRef:
              name: nginx-config
              key: nginx_port
        - name: NGINX_SERVER_NAME
          valueFrom:
            configMapKeyRef:
              name: nginx-config
              key: server_name

*  将cm通过存储卷方式以文件注入容器

apiVersion: v1
    kind: Pod
    metadata:
      name: pod-cm-2
      namespace: default
      labels:
        app: myapp
        tier: frontend
      annotations:
        dongfei.tech/created-by: "cluster admin"
    spec:
      containers:
      - name: myapp
        image: dongfeimg/myapp:v1
        imagePullPolicy: IfNotPresent
        ports:
        - name: http
          containerPort: 80
        volumeMounts:
        - name: nginxconf
          mountPath: /etc/nginx/conf.d/
          readOnly: true
      volumes:
      - name: nginxconf
        configMap:
          name: nginx-www

*  将secret通过环境变量方式注入容器

apiVersion: v1
    kind: Pod
    metadata:
      name: pod-secret-1
      namespace: default
      labels:
        app: myapp
        tier: frontend
      annotations:
        dongfei.tech/created-by: "cluster admin"
    spec:
      containers:
      - name: myapp
        image: dongfeimg/myapp:v1
        imagePullPolicy: IfNotPresent
        ports:
        - name: http
          containerPort: 80
        env:
        - name: MYSQL_ROOT_PASSWORD
          valueFrom:
            secretKeyRef:
              name: mysql-root-password
              key: password

转载于:https://www.cnblogs.com/L-dongf/p/11439882.html

[https_kubernetes.io_docs_concepts_storage_persistent-volumes_access-modes]: https://kubernetes.io/docs/concepts/storage/persistent-volumes/#access-modes