Last modified August 29, 2023

Tag Persistent Volumes on AWS

If your application needs additional storage, you usually create a Persistent Volume Claim (PVC) object and add this volume claim name to your Deployment or Stateful Set.

The AWS-EBS-CSI-Driver, which is installed by default in all workload clusters, is responsible for creating Elastic Block Storage (EBS) Volumes when creating EBS Persistent Volumes (PV) inside you cluster.

To tag your EBS volumes there are currently two ways:

1. Apply a new storage class with tag specifications
2. Install the optional aws-ebs-volume-tagger app in your cluster

Create a new storage class

With AWS-EBS-CSI-Driver version >= 1.6.0 you can set additional tags on the storage class will tag EBS volumes when being created. It will only tag EBS volumes when you create a new EBS volume not on any updates like resizing.

kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: example
provisioner: ebs.csi.aws.com
parameters:
  tagSpecification_1: "key1=value1"
  tagSpecification_2: "key2=hello world"
  tagSpecification_3: "key3=test"
  ...

Whenever you create a new PVC with this Storage Class it will set those tags on your EBS volumes.

Use the aws-ebs-volume-tagger app

The aws-ebs-volume-tagger is a optional app which can be applied to your cluster. It runs as a cronjob periodically (every 15 minutes) and checks if there are any PVs which need to be tagged in AWS.

To tag all your PV’s inside your cluster you need to add a User level config Yaml file with the following struct:

extraVolumeTags:
  tag.provider.giantswarm.io/example: test
  tag.provider.giantswarm.io/example2: test2
  ...

Note that every key must start with tag.provider.giantswarm.io otherwise it will be ignored.

The config is the source of truth, the tagger will always ensure only the tags inside the config will be applied to the EBS volumes inside your cluster. If an additional tag starting with tag.provider.giantswarm.io is added manually on one of your EBS volumes, it will be reverted.

The tagger only considers EBS volumes from a PV in your cluster.