kubernetes - 副本之间的 Kubernetes 部署的共享目录

Question

我有一个带有 2 个副本的简单部署。

我希望每个副本都有相同的存储文件夹(共享应用程序上传文件夹)

我一直在玩 claim 和数量，但还没有优势，所以寻求快速帮助/示例。

apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: 'test-tomcat'
      labels:
        app: test-tomcat
    spec:
      selector:
        matchLabels:
          app: test-tomcat
      replicas: 3
      template:
        metadata:
          name: 'test-tomcat'
          labels:
            app: test-tomcat
        spec:
          volumes:
          - name: 'data'
            persistentVolumeClaim:
              claimName: claim
          containers:
          - image: 'tomcat:9-alpine'
            volumeMounts:
            - name: 'data'
              mountPath: '/app/data'
            imagePullPolicy: Always
            name: 'tomcat'
            command: ['bin/catalina.sh', 'jpda', 'run']

kind: PersistentVolume
apiVersion: v1
metadata:
  name: volume
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 2Gi
  accessModes:
  - ReadWriteMany
  hostPath:
    path: "/mnt/data"

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: claim
spec:
  storageClassName: manual
  accessModes:
  - ReadWriteMany
  resources:
    requests:
      storage: 1Gi

Answer 1

首先，您需要决定使用哪种类型的持久卷。以下是本地集群的几个示例:

主机路径 - 节点上的本地路径。因此，如果第一个 Pod 位于 Node1 上，而第二个 Pod 位于 Node2 上，则存储空间会有所不同。要解决此问题，您可以使用以下选项之一。主机路径示例:

kind: PersistentVolume
apiVersion: v1
metadata:
  name: example-pv
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 3Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/mnt/data"

NFS - 该类型的 PersistentVolume 使用网络文件系统。 NFS 是一种分布式文件系统协议(protocol)，允许您在服务器上挂载远程目录。在 Kubernetes 中使用 NFS 之前需要安装 NFS 服务器；这是示例 How To Set Up an NFS Mount on Ubuntu . Kubernetes 中的示例:

apiVersion: v1
kind: PersistentVolume
metadata:
  name: example-pv
spec:
  capacity:
    storage: 3Gi
  volumeMode: Filesystem
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Recycle
  storageClassName: slow
  mountOptions:
    - hard
    - nfsvers=4.1
  nfs:
    path: /tmp
    server: 172.17.0.2

GlusterFS - GlusterFS 是一个可扩展的分布式文件系统，它将来自多个服务器的磁盘存储资源聚合到一个单一的全局命名空间中。至于 NFS，在 Kubernetes 中使用前需要安装 GlusterFS；这是link有说明，和one更多的 sample 。 Kubernetes 中的示例:

apiVersion: v1
kind: PersistentVolume
metadata:
  name: example-pv 
  annotations:
    pv.beta.kubernetes.io/gid: "590" 
spec:
  capacity:
    storage: 3Gi 
  accessModes: 
    - ReadWriteMany
  glusterfs:
    endpoints: glusterfs-cluster 
    path: myVol1 
    readOnly: false
  persistentVolumeReclaimPolicy: Retain
---
apiVersion: v1
kind: Service
metadata:
  name: glusterfs-cluster 
spec:
  ports:
  - port: 1
---
apiVersion: v1
kind: Endpoints
metadata:
  name: glusterfs-cluster 
subsets:
  - addresses:
      - ip: 192.168.122.221 
    ports:
      - port: 1 
  - addresses:
      - ip: 192.168.122.222 
    ports:
      - port: 1 
  - addresses:
      - ip: 192.168.122.223 
    ports:
      - port: 1 

创建 PersistentVolume 后，您需要创建 PersistaentVolumeClaim。 PersistaentVolumeClaim 是 Pod 用来从存储中请求卷的资源。创建 PersistentVolumeClaim 后，Kubernetes 控制平面会查找满足声明要求的 PersistentVolume。例子:

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: example-pv-claim
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 3Gi

最后一步，您需要配置一个 Pod 以使用 PersistentVolumeClaim。这是示例:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: 'test-tomcat'
  labels:
    app: test-tomcat
spec:
  selector:
    matchLabels:
      app: test-tomcat
  replicas: 3
  template:
    metadata:
      name: 'test-tomcat'
      labels:
        app: test-tomcat
    spec:
      volumes:
      - name: 'data'
        persistentVolumeClaim:
          claimName: example-pv-claim #name of the claim should be the same as defined before
      containers:
      - image: 'tomcat:9-alpine'
        volumeMounts:
        - name: 'data'
          mountPath: '/app/data'
        imagePullPolicy: Always
        name: 'tomcat'
        command: ['bin/catalina.sh', 'jpda', 'run']