Kubernetes persistent data store StorageClass

The article links PV and PVC patterns by first creating PV and then defining PVC for one-to-one binding. If you encounter a large cluster, do you also create one by one? So it’s expensive to maintain and it’s a lot of work. Kubernetes provides a mechanism for automatically creating PVS, called StorageClass, which creates PV templates.

StorageClass defines two parts:

PV attributes: such as storage size, type, etc
PV needs to use storage plug-ins such as Ceph;

With these two pieces of information, Kubernetes can find the corresponding StorageClass based on the PVC submitted by the user, and then Kubernetes will call the StorageClass declared storage plug-in to automatically create the PV.

To use NFS, however, we need a plug-in for NFS-Client. This plugin will cause the NFS service to automatically create PVS for us.

${namespace}-${pvcName}-${pvName} -${pvName} Archieved -${namespace}-${pvcName}-${pvName} -${pvName} format storage details can be reference Github PV, PVC, NFS no further description, not complete please check kubernetes using PV and PVC management data storage

Create ServiceAccount

The ServiceAccount is created to authorize nfS-Client.

#Download the rbac. Yamlwget https://github.com/kubernetes-retired/external-storage/blob/201f40d78a9d3fd57d8a441cfc326988d88f35ec/nfs-client/deploy/r bac.yamlCopy the code

The deployment of rbac. Yaml

kubectl  apply  -f   rbac.yaml 
#The output is as follows
serviceaccount/nfs-client-provisioner created
clusterrole.rbac.authorization.k8s.io/nfs-client-provisioner-runner created
clusterrolebinding.rbac.authorization.k8s.io/run-nfs-client-provisioner created
role.rbac.authorization.k8s.io/leader-locking-nfs-client-provisioner created
rolebinding.rbac.authorization.k8s.io/leader-locking-nfs-client-provisioner created
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Create the NFS client

Use Deployment to create the NFS-client

#Download deployment. Yamlwget https://github.com/kubernetes-retired/external-storage/blob/201f40d78a9d3fd57d8a441cfc326988d88f35ec/nfs-client/deploy/d eployment.yamlCopy the code

Modify yamL as follows

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nfs-client-provisioner
  labels:
    app: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: default
spec:
  replicas: 1
  strategy:
    type: Recreate
  selector:
    matchLabels:
      app: nfs-client-provisioner
  template:
    metadata:
      labels:
        app: nfs-client-provisioner
    spec:
      serviceAccountName: nfs-client-provisioner
      containers:
        - name: nfs-client-provisioner
          image: quay.io/external_storage/nfs-client-provisioner:latest
          volumeMounts:
            - name: nfs-client-root
              mountPath: /persistentvolumes
          env:
            - name: PROVISIONER_NAME
              value: fuseim.pri/ifs      The supplier name must be the same as the provisioner name in class.yaml, otherwise the deployment will not succeed
            - name: NFS_SERVER
              value: 10.010.51.          Write the IP address of the NFS server or the resolvable host name
            - name: NFS_PATH
              value: /home/bsh/nfs       The path must be the last folder in the directory, otherwise the application will not have permission to create the directory causing Pending.
      volumes:
        - name: nfs-client-root
          nfs:
            server: 10.010.51.          The IP address or resolvable host name of the NFS server
            path: /home/bsh/nfs        # shared mount directory on NFS server (note: the path must be the last folder in the directory, otherwise the deployed application will not have permission to create the directory causing Pending)
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⚠️ Note value: fuseiem.pri /ifs # The supplier name must be the same as the provisioner name in class. Yaml otherwise, the deployment will not succeed

Create a check

#Deploy the NFS client
kubectl  apply  -f   deployment.yaml
#The output is as follows
deployment.apps/nfs-client-provisioner created
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Check the pod

kubectl get pod
#The output is as follows
NAME                                     READY   STATUS    RESTARTS   AGE
nfs-client-provisioner-fd74f99b4-wr58j   1/1     Running   1          30s
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Create StorageClass

Yaml class. Yaml class. Yaml class

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: managed-nfs-storage
provisioner: fuseim.pri/ifs # or choose another name, must match deployment's env PROVISIONER_NAME'
parameters:
  archiveOnDelete: "false"
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⚠️ Note that the provisioner must be the same as the value of the PROVISIONER_NAME from the YAML file in the Deployment above.

Create storageclass

#create 
kubectl  apply  -f  class.yaml 
#The output is as follows
storageclass.storage.k8s.io/managed-nfs-storage created
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Check the status

kubectl get storageclass
#The output is as follows
NAME                  PROVISIONER      RECLAIMPOLICY   VOLUMEBINDINGMODE   ALLOWVOLUMEEXPANSION   AGE
managed-nfs-storage   fuseim.pri/ifs   Delete          Immediate           false                  53s
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Create a PVC

Create a tomcat storageclass – PVC, yaml

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: tomcat
  annotations:
    volume.beta.kubernetes.io/storage-class: "managed-nfs-storage"
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 500Mi
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The deployment of yaml

kubectl  apply  -f tomcat-storageclass-pvc.yaml
#The output is as follows
persistentvolumeclaim/tomcat created
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Check the status

kubectl get pvc
#The output is as follows
NAME         STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS          AGE
tomcat       Bound    pvc-d35c82e3-29f3-4f6d-b25d-3ccdd365d1ec   500Mi      RWX            managed-nfs-storage   48s
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Pod uses added PVC

Also take the previous tomcat experiment, we take the logs in the Tomcat directory to the local NFS.

⚠️ Note That if a POD is created using PVC, it cannot be successfully created. Please refer to the error when it appearsPersistentvolume-controller waiting for a volume to be created

The specific YAML is as follows:

apiVersion: apps/v1 
kind: Deployment   
metadata:             
  name: tomcat-deployment     
  labels:       
    app: tomcat  
spec:          
  replicas: 3
  selector:      
    matchLabels: 
      app: tomcat
  minReadySeconds: 1
  progressDeadlineSeconds: 60
  revisionHistoryLimit: 2
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
  template:        
    metadata:  
      labels:  
        app: tomcat
    spec:         
      containers:     
      - name: tomcat     
        image: wenlongxue/tomcat:tomcat-demo-62-123xw2    
        imagePullPolicy: Always          
        ports:
        - containerPort: 8080
        resources:
          requests:
            memory: "2Gi"
            cpu: "80m"
          limits: 
            memory: "2Gi" 
            cpu: "80m"
        readinessProbe:
          httpGet:
            path: /
            port: 8080
          initialDelaySeconds: 180
          periodSeconds: 5
          timeoutSeconds: 3
          successThreshold: 1
          failureThreshold: 30
        volumeMounts:
        - mountPath: "/usr/local/tomcat/logs"
          name: tomcat
# PVC part
      volumes:
      - name: tomcat
        persistentVolumeClaim:
          claimName: tomcat
---
# Service indicates the Service
apiVersion: v1
kind: Service
metadata:      
  name: tomcat-service
  labels:      
    app: tomcat 
spec:        
  selector:   
    app: tomcat  
  ports:
  - name: tomcat-port 
    protocol: TCP      
    port: 8080         
    targetPort: 8080   
  type: ClusterIP 
---
# ingress service section
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: tomcat
  annotations:
    kubernetes.io/ingress.class: "nginx"
spec:
  tls:
  - hosts:
    - tomcat.cnsre.cn
    secretName: tls-secret
  rules:
  - host: tomcat.cnsre.cn
    http:
      paths:
      - path: "/"
        pathType: Prefix
        backend:
          service:
            name: tomcat-service
            port:
              number: 8080
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Deploying pod Services

kubectl  apply  -f tomcatc.yaml
#The output is as follows
deployment.apps/tomcat-deployment created
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Check the status

kubectl get pod
#The output is as follows
NAME                                     READY   STATUS    RESTARTS   AGE
nfs-client-provisioner-fd74f99b4-wr58j   1/1     Running   0          76m
tomcat-deployment-7588b5c8fd-cnwvt       1/1     Running   0          59m
tomcat-deployment-7588b5c8fd-kl8fj       1/1     Running   0          59m
tomcat-deployment-7588b5c8fd-ksbg9       1/1     Running   0          59m
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Check the PV PVC

[root@master tomccat]# kubectl get pv,pvc NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE  persistentvolume/pvc-d35c82e3-29f3-4f6d-b25d-3ccdd365d1ec 500Mi RWX Delete Bound default/tomcat managed-nfs-storage 65m  NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE persistentvolumeclaim/tomcat Bound pvc-d35c82e3-29f3-4f6d-b25d-3ccdd365d1ec 500Mi RWX managed-nfs-storage 65mCopy the code

View information about the NFS Server directory

[root@node1 ~]# ll /home/bsh/nfs/default-tomcat-PVC-d35c82E3-29f3-4f6d-b25d-3ccDD365d1ec/total 220-rw-r -----. 1 root Root 22217 sep 3 14:49 catalina.2021-09-03.log -rw-r-----. 1 root root 0 Sep 3 14:41 host-manager.2021-09-03.log 1 root root 2791 9月 3 14:49 localhost.2021-09-03.log -rw-r-----. 1 root root 118428 9月 3 15:31 Localhost_access_log.2021-09-03.txt -rw-r-----. 1 root root 09 月 3 14:41 manager.2021-09-03.logCopy the code

The article links

Kubernetes persistent data store StorageClass

Create ServiceAccount

Create the NFS client

Create StorageClass

Create a PVC

Pod uses added PVC

Check the PV PVC

View information about the NFS Server directory

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