Amazon EFS CSI Operations

External

• https://github.com/kubernetes-sigs/aws-efs-csi-driver

Internal

• Amazon EFS CSI

Deploy the Amazon EFS CSI Driver

Ensure you are in the right context, with sufficient permissions.

The command to deploy is provided below, but always check with the original documentation to make sure you use the latest verison:

kubectl apply -k "github.com/kubernetes-sigs/aws-efs-csi-driver/deploy/kubernetes/overlays/stable/ecr/?ref=release-1.1.0"

Current releases: https://github.com/kubernetes-sigs/aws-efs-csi-driver/tags

This deploys a CSIDriver and a DaemonSet resources:

kubectl get csidriver
NAME              CREATED AT
efs.csi.aws.com   2020-06-24T04:29:45Z

kubectl get -n kube-system daemonset
NAME           DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR                                     AGE
efs-csi-node   3         3         3       3            3           kubernetes.io/arch=amd64,kubernetes.io/os=linux   57d

Deploy the EFS Storage Class

cat <<EOF | kubectl apply -f -
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: efs-sc
provisioner: efs.csi.aws.com
EOF

storageclass.storage.k8s.io/efs-sc created
kubectl get sc
NAME            PROVISIONER             AGE
[...]
efs-sc          efs.csi.aws.com         16s

Deploy the EFS Persistent Volume

There is an one-to-one relationship between the Persistent Volume and the EFS file system, so the name of the EFS filesystem can be used.

apiVersion: v1
kind: PersistentVolume
metadata:
  name: efs-pv-01
spec:
  capacity:
    storage: 1Gi
  volumeMode: Filesystem
  accessModes:
    - ReadWriteMany
  persistentVolumeReclaimPolicy: Retain
  storageClassName: efs-sc
  csi:
    driver: efs.csi.aws.com
    volumeHandle: fs-99999999

kubectl apply -f persistent-volume.yaml
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM                     STORAGECLASS   REASON   AGE
[...]
efs-pv-01                                  1Gi        RWX            Retain           Available                             efs-sc                  38s

Deploy the Persistent Volume Claim

For a discussion on what combination of storage class and persistent volume names work, see Persistent Volume Claims and Storage Class. Usually one can specify only the storage class, or the storage class and a persistent volume name. However, when we rely on getting a specific EFS file system, which is in most case desirable, specifying the volume name is a good idea. For more syntax details, see Persistent Volume Claim manifest.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: efs-pv-01
  namespace: test
spec:
  accessModes:
    - ReadWriteMany
  storageClassName: efs-sc
  volumeName: efs-pv-01
  resources:
    requests:
      storage: 1Gi

kubectl apply -f persistent-volume-claim.yaml
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM                     STORAGECLASS   REASON   AGE
[...]
efs-pv-01                                  1Gi        RWX            Retain           Available                             efs-sc                  38s

Mount in Pod

apiVersion: v1
kind: Pod
metadata:
  name: app1
spec:
  containers:
  - name: app1
    image: busybox
    command: ["/bin/sh"]
    args: ["-c", "while true; do echo $(date -u) >> /data/out1.txt; sleep 5; done"]
    volumeMounts:
    - name: persistent-storage
      mountPath: /data
  volumes:
  - name: persistent-storage
    persistentVolumeClaim:
      claimName: efs-pv-01

Troubleshooting

The EFS filesystem cannot be mounted on EKS worker nodes

The symptoms include the pod that attempts mounting the volume getting stuck in "ContainerCreating". One of the causes is that the security groups associated with the worker nodes do not allow IP connectivity to/from the mount targets. If possible, try to manually mount the filesystem on the worker nodes, as a test.