Steps to set up NFS based Persistent Volumes

Set up NFS Common

On all kubernetes nodes, if you have not already installed nfs, use the following command to do so

sudo apt-get update
sudo apt-get install nfs-common

[Skip this step if you are using a vagrant setup recommended as part of this course. ]

Set up NFS Provisioner in kubernetes

Change into nfs provisioner installation dir

cd k8s-code/storage

Deploy nfs-client provisioner.

kubectl apply -f nfs

This will create all the objects required to setup a nfs provisioner.

Creating a Persistent Volume Claim

switch to project directory

cd k8s-code/projects/instavote/dev/

file: db-pvc.yaml

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: db-pvc
spec:
  accessModes:
    - ReadWriteOnce
  volumeMode: Filesystem
  resources:
    requests:
      storage: 2Gi
  storageClassName: nfs

And lets create the Persistent Volume Claim

kubectl get pvc,storageclass

kubectl logs -f nfs-provisioner-0

kubectl apply -f db-pvc.yaml

kubectl get pvc,storageclass

kubectl describe pvc db-pvc

file: db-deploy.yaml

...
spec:
   containers:
   - image: postgres:9.4
     imagePullPolicy: Always
     name: db
     ports:
     - containerPort: 5432
       protocol: TCP
     #mount db-vol to postgres data path
     volumeMounts:
     - name: db-vol
       mountPath: /var/lib/postgresql/data
   #create a volume with pvc
   volumes:
   - name: db-vol
     persistentVolumeClaim:
       claimName: db-pvc

Observe which host db pod is running on

kubectl get pod -o wide --selector='role=db'

And apply this code as

kubectl apply -f db-deploy.yaml

kubectl get pod -o wide --selector='role=db'

• Observe the volume and its content created on the nfs server
• Observe which host the pod for db was created this time. Analyse the behavior of a deployment controller.