Skip to content

Latest commit

 

History

History
223 lines (188 loc) · 10.2 KB

modify-volume.md

File metadata and controls

223 lines (188 loc) · 10.2 KB
Raw

Volume Modification

The EBS CSI Driver (starting from v1.19.0) supports volume modification through two methods:

Installation

ControllerModifyVolume via VolumeAttributesClass (Recommended)

VolumeAttributesClass support is controlled by the Kubernetes VolumeAttributesClass feature gate.

To use this feature, it must be enabled in the following places:

  • VolumeAttributesClass feature gate on kube-apiserver (consult your Kubernetes distro's documentation)
  • storage.k8s.io/v1alpha1 enabled in kube-apiserver via runtime-config (consult your Kubernetes distro's documentation)
  • VolumeAttributesClass feature gate on kube-controller-manager (consult your Kubernetes distro's documentation)
  • VolumeAttributesClass feature gate on external-provisioner (add --feature-gates=VolumeAttributesClass=true to sidecars.provisioner.additionalArgs when using the EBS CSI Helm chart)
  • VolumeAttributesClass feature gate on kube-controller-manager (add --feature-gates=VolumeAttributesClass=true to sidecars.resizer.additionalArgs when using the EBS CSI Helm chart)

For more information, see the Kubernetes documentation for the feature.

volume-modifier-for-k8s

To enable this feature through the Helm chart, users must set controller.volumeModificationFeature.enabled in values.yaml to true.

This will install an additional sidecar (volumemodifier) that watches the Kubernetes API server for changes to PVC annotations and triggers an RPC call against the CSI driver.

Parameters

Users can specify the following modification parameters:

  • type: to update the volume type
  • iops: to update the IOPS
  • throughput: to update the throughput

Considerations

  • Keep in mind the 6 hour cooldown period for EBS ModifyVolume. Multiple ModifyVolume calls for the same volume within a 6 hour period will fail.
  • Ensure that the desired volume properties are permissible. The driver does minimum client side validation.

Example

ControllerModifyVolume via VolumeAttributesClass

See the EBS CSI example with manifests.

volume-modifier-for-k8s

1) Create a PVC.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: ebs-claim
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: ebs-sc
  resources:
    requests:
      storage: 100Gi
---
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: ebs-sc
provisioner: ebs.csi.aws.com
volumeBindingMode: WaitForFirstConsumer
---
apiVersion: v1
kind: Pod
metadata:
  name: app
spec:
  containers:
  - name: app
    image: centos
    command: ["/bin/sh"]
    args: ["-c", "while true; do echo $(date -u) >> /data/out.txt; sleep 5; done"]
    volumeMounts:
    - name: persistent-storage
      mountPath: /data
  volumes:
  - name: persistent-storage
    persistentVolumeClaim:
      claimName: ebs-claim

2) Verify the PVC is created.

$ k describe pvc ebs-claim
Name:          ebs-claim
Namespace:     default
StorageClass:  ebs-sc
Status:        Bound
Volume:        pvc-20c5ddec-5913-4b8d-a2fc-bfd0943b966d
Labels:        <none>
Annotations:   pv.kubernetes.io/bind-completed: yes
               pv.kubernetes.io/bound-by-controller: yes
               volume.beta.kubernetes.io/storage-provisioner: ebs.csi.aws.com
               volume.kubernetes.io/selected-node: ip-192-168-32-79.ec2.internal
               volume.kubernetes.io/storage-provisioner: ebs.csi.aws.com
Finalizers:    [kubernetes.io/pvc-protection]
Capacity:      100Gi
Access Modes:  RWO
VolumeMode:    Filesystem
Used By:       app
Events:
  Type     Reason                 Age              From                                                                                     Message
  ----     ------                 ----             ----                                                                                     -------
  Warning  ProvisioningFailed     6s               persistentvolume-controller                                                              storageclass.storage.k8s.io "ebs-sc" not found
  Normal   Provisioning           5s               ebs.csi.aws.com_ebs-csi-controller-b84fbbd88-5z66k_d2cb941a-aee8-41d6-aea5-8f4a40c7c82c  External provisioner is provisioning volume for claim "default/ebs-claim"
  Normal   ExternalProvisioning   4s (x2 over 5s)  persistentvolume-controller                                                              waiting for a volume to be created, either by external provisioner "ebs.csi.aws.com" or manually created by system administrator
  Normal   ProvisioningSucceeded  1s               ebs.csi.aws.com_ebs-csi-controller-b84fbbd88-5z66k_d2cb941a-aee8-41d6-aea5-8f4a40c7c82c  Successfully provisioned volume pvc-20c5ddec-5913-4b8d-a2fc-bfd0943b966d

3) (Optional) Verify volume properties in EBS.

$ pv=$(k get -o json pvc ebs-claim | jq -r '.spec | .volumeName')
$ volumename=$(k get -o json pv $pv | jq -r '.spec | .csi | .volumeHandle')
$ aws ec2 describe-volumes —volume-ids $volumename | jq '.Volumes[] | "\(.VolumeType) \(.Iops) \(.Throughput)"'
"gp3 3000 125"

4) Edit the PVC with annotations.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: ebs-claim
  annotations:
	ebs.csi.aws.com/volumeType: "io2"
	ebs.csi.aws.com/iops: "4000"
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: ebs-sc
  resources:
    requests:
      storage: 100Gi

5) Verify the volume has been updated successfully.

$ k describe pvc ebs-claim
Name:          ebs-claim
Namespace:     default
StorageClass:  ebs-sc
Status:        Bound
Volume:        pvc-6bff47f9-1843-4576-ba15-158c73491e8c
Labels:        <none>
Annotations:   ebs.csi.aws.com/iops: 4000
               ebs.csi.aws.com/volumeType: io2
               pv.kubernetes.io/bind-completed: yes
               pv.kubernetes.io/bound-by-controller: yes
               volume.beta.kubernetes.io/storage-provisioner: ebs.csi.aws.com
               volume.kubernetes.io/selected-node: ip-192-168-88-208.us-east-2.compute.internal
               volume.kubernetes.io/storage-provisioner: ebs.csi.aws.com
Finalizers:    [kubernetes.io/pvc-protection]
Capacity:      100Gi
Access Modes:  RWO
VolumeMode:    Filesystem
Used By:       app
Events:
  Type     Reason                        Age                    From                                                                                      Message
  ----     ------                        ----                   ----                                                                                      -------
  Warning  ProvisioningFailed            7m51s                  persistentvolume-controller                                                               storageclass.storage.k8s.io "ebs-sc" not found
  Normal   WaitForPodScheduled           7m49s                  persistentvolume-controller                                                               waiting for pod app to be scheduled
  Normal   ExternalProvisioning          7m49s (x2 over 7m49s)  persistentvolume-controller                                                               waiting for a volume to be created, either by external provisioner "ebs.csi.aws.com" or manually created by system administrator
  Normal   Provisioning                  7m49s                  ebs.csi.aws.com_ebs-csi-controller-6bb6b754f7-kqpzm_27524e89-857b-4197-b801-e48576823e89  External provisioner is provisioning volume for claim "default/ebs-claim"
  Normal   ProvisioningSucceeded         7m46s                  ebs.csi.aws.com_ebs-csi-controller-6bb6b754f7-kqpzm_27524e89-857b-4197-b801-e48576823e89  Successfully provisioned volume pvc-6bff47f9-1843-4576-ba15-158c73491e8c
  Normal   VolumeModificationStarted     4s                     volume-modifier-for-k8s-ebs.csi.aws.com                                                   External modifier is modifying volume pvc-6bff47f9-1843-4576-ba15-158c73491e8c
  Normal   VolumeModificationSuccessful  1s                     volume-modifier-for-k8s-ebs.csi.aws.com                                                   External modifier has successfully modified volume pvc-6bff47f9-1843-4576-ba15-158c73491e8c

You will notice that the annotations have been applied to the PV as well.

$ k describe pv           
Name:              pvc-6bff47f9-1843-4576-ba15-158c73491e8c
Labels:            <none>
Annotations:       ebs.csi.aws.com/iops: 4000
                   ebs.csi.aws.com/volumeType: io2
                   pv.kubernetes.io/provisioned-by: ebs.csi.aws.com
                   volume.kubernetes.io/provisioner-deletion-secret-name: 
                   volume.kubernetes.io/provisioner-deletion-secret-namespace: 
Finalizers:        [kubernetes.io/pv-protection external-attacher/ebs-csi-aws-com]
StorageClass:      ebs-sc
Status:            Bound
Claim:             default/ebs-claim
Reclaim Policy:    Delete
Access Modes:      RWO
VolumeMode:        Filesystem
Capacity:          100Gi
Node Affinity:     
  Required Terms:  
    Term 0:        topology.ebs.csi.aws.com/zone in [us-east-2b]
Message:           
Source:
    Type:              CSI (a Container Storage Interface (CSI) volume source)
    Driver:            ebs.csi.aws.com
    FSType:            ext4
    VolumeHandle:      vol-02cb54d01c685b919
    ReadOnly:          false
    VolumeAttributes:      storage.kubernetes.io/csiProvisionerIdentity=1684161810754-8081-ebs.csi.aws.com
Events:                <none>

Do NOT delete these annotations. These annotations are used by the sidecar to reconcile the PVC's state when modifying annotations.

6) (Optional) Validate the volume has been modified in EBS.

$ aws ec2 describe-volumes --volume-ids $volumename | jq '.Volumes[] | "\(.VolumeType) \(.Iops) \(.Throughput)"'
"io2 4000 null"