Facing an issue with attaching EFS volume to Kubernetes pods

Question

I am running my docker containers with the help of kubernetes cluster on AWS EKS. Two of my docker containers are using shared volume and both of these containers are runnin

Answer 1

The issue was, I had 2 ec2 instances running, but I mounted EFS volume to only one of the ec2 instances and kubectl was always deploying pods on the ec2 instance which doesn't have the mounted volume. Now I mounted the same volume to both the instances and using PVC, PV like below. It is working fine.

ec2 mounting: AWS EFS mounting with EC2

PV.yml

apiVersion: v1
kind: PersistentVolume
metadata:
  name: efs
spec:
  capacity:
    storage: 100Mi
  accessModes:
    - ReadWriteMany
  nfs:
    server: efs_public_dns.amazonaws.com
    path: "/"

PVC.yml

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: efs
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 100Mi

replicaset.yml

----- only volume section -----

 volumes:
  - name: test-volume
    persistentVolumeClaim:
      claimName: efs

Answer 2

AWS EFS uses NFS type volume plugin, and As per Kubernetes Storage Classes NFS volume plugin does not come with internal Provisioner like EBS.

So the steps will be:

1. Create an external Provisioner for NFS volume plugin.
2. Create a storage class.
3. Create one volume claim.

4. Use volume claim in Deployment.

   • In the configmap section change the file.system.id: and aws.region: to match the details of the EFS you created.

   • In the deployment section change the server: to the DNS endpoint of the EFS you created.

---

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: efs-provisioner
data:
  file.system.id: yourEFSsystemid
  aws.region: regionyourEFSisin
  provisioner.name: example.com/aws-efs

---
kind: Deployment
apiVersion: extensions/v1beta1
metadata:
  name: efs-provisioner
spec:
  replicas: 1
  strategy:
    type: Recreate 
  template:
    metadata:
      labels:
        app: efs-provisioner
    spec:
      containers:
        - name: efs-provisioner
          image: quay.io/external_storage/efs-provisioner:latest
          env:
            - name: FILE_SYSTEM_ID
              valueFrom:
                configMapKeyRef:
                  name: efs-provisioner
                  key: file.system.id
            - name: AWS_REGION
              valueFrom:
                configMapKeyRef:
                  name: efs-provisioner
                  key: aws.region
            - name: PROVISIONER_NAME
              valueFrom:
                configMapKeyRef:
                  name: efs-provisioner
                  key: provisioner.name
          volumeMounts:
            - name: pv-volume
              mountPath: /persistentvolumes
      volumes:
        - name: pv-volume
          nfs:
            server: yourEFSsystemID.efs.yourEFSregion.amazonaws.com
            path: /

---
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: aws-efs
provisioner: example.com/aws-efs

---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: efs
  annotations:
    volume.beta.kubernetes.io/storage-class: "aws-efs"
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 1Mi

For more explanation and details go to https://github.com/kubernetes-incubator/external-storage/tree/master/aws/efs

Answer 3

The problem for me was that I was specifying a different path in my PV than /. And the directory on the NFS server that was referenced beyond that path did not yet exist. I had to manually create that directory first.