K8S当中的本地卷(Local PV)的使用

Local PV是从kuberntes 1.10开始引入，本质目的是为了解决hostPath的缺陷。通过PV控制器与Scheduler的结合，会对local PV做针对性的逻辑处理，从而，让Pod在多次调度时，能够调度到同一个Node上。

这次，测试了一下将local PV挂载到一个httpd的应用上。

要注意，pvc是按namespace提供的。还有，matchExpressions作匹配的主机名规则。

一，local-pv.yaml

kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: local-storage
provisioner: kubernetes.io/no-provisioner
volumeBindingMode: WaitForFirstConsumer
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: local-pv-sda
spec:
  capacity:
    storage: 100Gi
  accessModes:
  - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  storageClassName: local-storage
  local:
    path: /data/pv
  nodeAffinity:
    required:
      nodeSelectorTerms:
      - matchExpressions:
        - key: kubernetes.io/hostname
          operator: In
          values:
          - spark-docker
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: local-pvc-sda
  namespace: in-demo
spec:
  accessModes:
  - ReadWriteOnce
  storageClassName: local-storage
  resources:
    requests:
      storage: 10Gi

二，httpd.yaml

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: httpd
  namespace: in-demo
spec:
  replicas: 2
  revisionHistoryLimit: 5
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 0
  template:
    metadata:
      labels:
        app: httpd-dm
    spec:
      terminationGracePeriodSeconds: 60
      restartPolicy: Always
      containers:
      - name: httpd
        image: httpd:alpine
        imagePullPolicy: IfNotPresent
        volumeMounts:
        - name: storage-localpv
          mountPath: "/usr/local/apache2/htdocs"
      volumes:
      - name: storage-localpv
        persistentVolumeClaim:
          claimName: local-pvc-sda
---
apiVersion: v1
kind: Service
metadata:
    name: httpd-svc
    namespace: in-demo
spec:
  ports:
    - name: http-port
      port: 80
      targetPort: 80
  selector:
    app: httpd-dm