如何将 EFS 添加到 Amazon-EKS 上的 Airflow 部署？

Question

Kube.netes and EKS newbie here.

I've set up an Elastic Kube.netes Service (EKS) cluster and added an Airflow deployment on top of it using the official HELM chart for Apache Airflow . I configured gitsync and can successfully run my DAGS. For some of the DAGs, I need to save the data to an Amazon EFS. I installed the Amazon EFS CSI driver on eks following the instruction on the amazon documentation .

Now, I can create a new pod with access to the NFS but the airflow deployment broke and stay in a state of Back-off restarting failed container . I also got the events with kubectl -n airflow get events --sort-by='{.lastTimestamp} and I get the following messages:

TYPE      REASON               OBJECT                                            MESSAGE

Warning   BackOff              pod/airflow-scheduler-599fc856dc-c4pgz            Back-off restarting failed container

Normal    FailedBinding        persistentvolumeclaim/redis-db-airflow-redis-0    no persistent volumes available for this claim and no storage class is set

Warning   ProvisioningFailed   persistentvolumeclaim/ebs-claim                   storageclass.storage.k8s.io "ebs-sc" not found

Normal    FailedBinding        persistentvolumeclaim/data-airflow-postgresql-0   no persistent volumes available for this claim and no storage class is set

I have tried this on EKS version 1.22.

I understand from this that airflow is expecting to get an EBS volume for its pods but the NFS driver changed the configuration of the pvs.

The pvs before I install the driver are this:

NAME CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM STORAGECLASS   REASON   AGE
pvc-######   100Gi      RWO            Delete           Bound    airflow/logs-airflow-worker-0       gp2                     1d

pvc-######   8Gi        RWO            Delete           Bound    airflow/data-airflow-postgresql-0   gp2                 1d

pvc-######   1Gi        RWO            Delete           Bound    airflow/redis-db-airflow-redis-0    gp2                     1d

After I install the EFS CSI driver, I see the pvs have changed.

NAME      CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM STORAGECLASS   REASON   AGE

efs-pvc   5Gi        RWX            Retain           Bound    efs-storage-claim   efs-sc                  2d

I have tried deploying airflow before or after installing the EFS driver and in both cases I get the same error.

How can I get access to the NFS from within Airflow without breaking the Airflow deployment on EKS. Any help would be appreciated.

Answer 1

As stated in the error above no persistent volumes available for this claim and no storage class is set and storageclass.storage.k8s.io "ebs-sc" not found , you have to deploy a storage class called efs-sc using the EFS CSI driver as a provisioner.

Further documentation could be found here

An example of creating your missing storage class and persistent volume could be found here

These steps are also described in the AWS EKS user guide