A new version of Anthos clusters on AWS (GKE on AWS) was released on April 6. See the release notes for more information.

Importing a preexisting EBS volume

Overview

If you already have an AWS Elastic Block Store (EBS) volume to import into Anthos clusters on AWS, you can create a PersistentVolume (PV) object and reserve it for a specific PersistentVolumeClaim (PVC).

This page explains how to create a PV by using an existing EBS volume populated with data, and how to use the PV in a Pod.

Before you begin

  • From your anthos-aws directory, use anthos-gke to switch context to your user cluster.
    cd anthos-aws
    env HTTP_PROXY=http://localhost:8118 \
    anthos-gke aws clusters get-credentials CLUSTER_NAME

Creating a PersistentVolume for a pre-existing EBS volume

You can import an existing EBS volume by specifying a new PV.

  1. Copy the following YAML into a file named existing-volume.yaml and complete your configuration by replacing the values:

    • volume-capacity: size of the volume. For example, 30Gi. For more information on specifying volume capacity in Kubernetes, see the Meaning of memory.
    • storage-class-name: the name of the StorageClass that provisions the volume. For example, you can use the default standard-rwo.

    • ebs-id: EBS volume id. For example, vol-05786ec9ec9526b67.

    • fs-type: The file system of the volume. For example, ext4.

    • zone: The AWS Availability Zone that hosts the EBS volume. For example, us-east-1c.

    apiVersion: v1
    kind: PersistentVolume
    metadata:
      name: volume-name
      annotations:
        pv.kubernetes.io/provisioned-by: ebs.csi.aws.com
    spec:
      capacity:
        storage: volume-capacity
      accessModes:
        - ReadWriteOnce
      persistentVolumeReclaimPolicy: Retain
      storageClassName: storage-class-name
      claimRef:
        name: my-pvc
        namespace: default
      csi:
        driver: ebs.csi.aws.com
        volumeHandle: ebs-volume-id
        fsType: file-system-type
      nodeAffinity:
        required:
          nodeSelectorTerms:
          - matchExpressions:
            - key: topology.ebs.csi.aws.com/zone
              operator: In
              values:
              - zone
    
  2. Apply the YAML to your cluster

    kubectl apply -f existing-volume.yaml
    
  3. Confirm the creation of your PV

    kubectl describe pv volume-name
    

    The output of this command contains the status of the PV.

Using the volume with a PersistentVolumeClaim and Pod

After you have imported your volume, you can create a PVC and a Pod that attaches the PVC.

The YAML below creates a PVC and attaches it to a Pod running the Nginx web server. Copy it into a file named nginx.yaml and complete your configuration by replacing the values:

  • storage-class: The name of the StorageClass from the PersistentVolume you created previously. For example, standard-rwo.
  • volume-name: The name of the volume you created previously.
  • volume-capacity: size of the volume. For example, 30Gi.
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: my-pvc
spec:
  storageClassName: storage-class-name
  volumeName: volume-name
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: volume-capacity
---

apiVersion: v1
kind: Pod
metadata:
  name: web-server
spec:
  containers:
   - name: web-server
     image: nginx
     volumeMounts:
       - mountPath: /var/lib/www/html
         name: data
  volumes:
   - name: data
     persistentVolumeClaim:
       claimName: volume-name
  1. Apply the YAML to your cluster

    kubectl apply -f nginx.yaml
    
  2. Check the status of your Nginx instance with kubectl describe. The output should have a STATUS of Running.

    kubectl describe pod web-server
    

Using encrypted EBS volumes

If your EBS volume is encrypted with the AWS Key Management Service (KMS), you need to grant the Anthos clusters on AWS control plane AWS IAM role access to your KMS key.

To get the AWS IAM role name, perform the following steps:

  1. Change to the directory with your Anthos clusters on AWS configuration. You created this directory when Installing the management service.

    cd anthos-aws

  2. Choose if you created your Anthos clusters on AWS environment with the anthos-gke tool or if you created your AWS IAM profiles manually.

    anthos-gke tool

    Use the terraform output command and search for the value of iamInstanceProfile.

    terraform output | grep iamInstanceProfile
    

    If you created your Anthos clusters on AWS environment with the anthos- gke tool, the output looks like the following:

      iamInstanceProfile: gke-CLUSTER_ID-controlplane
      iamInstanceProfile: gke-CLUSTER_ID-nodepool
    

    Where CLUSTER_ID is your cluster's ID. Copy the value of gke-CLUSTER_ID-controlplane for the following step.

    Manually created

    Examine the output of terraform output with the following command:

    terraform output | less
    

    Scroll through the output and find the iamInstanceProfile after the AWSCluster definition.

    kind: AWSCluster
    metadata:
      name: cluster-0
    spec:
      ...
      controlPlane:
       ...
        iamInstanceProfile: INSTANCE_PROFILE_NAME
    

    Copy the value of INSTANCE_PROFILE_NAME for the following step.

  3. To grant the control plane access to your EBS volumes, add the gke-xxxxxx-controlplane AWS IAM profile as a Key User to the AWS KMS key used to encrypt your EBS volume.

What's next