Chainguard Container for kubernetes-csi-external-snapshot-controller

Sidecar container that watches Kubernetes Snapshot CRD objects and triggers CreateSnapshot/DeleteSnapshot against a CSI endpoint. This container image includes the snapshotter, snapshot-controller and snapshot-validation-webhook.

Chainguard Containers are regularly-updated, secure-by-default container images.

Download this Container Image

For those with access, this container image is available on cgr.dev:

docker pull cgr.dev/ORGANIZATION/kubernetes-csi-external-snapshot-controller:latest

Be sure to replace the ORGANIZATION placeholder with the name used for your organization's private repository within the Chainguard Registry.

Compatibility Notes

Chainguard's kubernetes-csi-external-snapshotter container image collection is a drop-in replacement for the following images:

• k8s.gcr.io/sig-storage/csi-snapshotter
• k8s.gcr.io/sig-storage/snapshot-controller
• k8s.gcr.io/sig-storage/snapshot-validation-webhook

Chainguard Container Images are designed with minimalism and security in mind, and thus the kubernetes-csi-external-snapshotter image has the following differences from the upstream image:

• We set the entrypoints to usr/bin/{component}, where as the upstream sets it to /{component}.

Getting Started

Snapshotter

To deploy the snapshotter, apply the manifests found in the upstream project here. You'll need to adjust the image to use cgr.dev/chainguard/kubernetes-csi-external-snapshotter instead. You can do this by extending the existing kustomization file as follows:

# ...
images:
  - name: registry.k8s.io/sig-storage/csi-snapshotter
    newName: cgr.dev/chainguard/kubernetes-csi-external-snapshotter
    digest: <insert image digest>

Snapshot Controller

To deploy the snapshotter, apply the manifests found in the upstream project here. You'll need to adjust the image to use cgr.dev/chainguard/kubernetes-csi-external-snapshot-controller instead. You can do this by extending the existing kustomization file as follows:

# ...
images:
  - name: registry.k8s.io/sig-storage/snapshot-controller
    newName: cgr.dev/chainguard/kubernetes-csi-external-snapshot-controller
    digest: <insert image digest>

Validation Webhook

As of Feb 2025, upstream looks to have deleted 'snapshot-validation-webhook' from the main branch. It still exists in the latest git release at this time: v8.1.11. It's likely this image will be depreciated in a future release.

To deploy the webhook, see the documentation in the upstream project. You'll just need to replace the container spec's image value with cgr.dev/ORGANIZATION/kubernetes-csi-external-snapshot-validation-webhook-fips.

You can verify that the webhook is working by following these instructions to submit an invalid snapshot definition and see whether it gets rejected.

Once all the components are deployed, you can try to apply one valid and one invalid snapshot to check the behavior.

Apply the following invalid Snapshot, which will be rejected by the validating webhook.

apiVersion: snapshot.storage.k8s.io/v1
kind: VolumeSnapshot
metadata:
  name: new-snapshot-demo-v1
spec:
  volumeSnapshotClassName: csi-hostpath-snapclass-v1
  source: # Only one of the two fields should be set for a snapshot. Therefore this snapshot is invalid.
    persistentVolumeClaimName: pvc 
    volumeSnapshotContentName: vsc

We can then apply the following valid Snapshot which will be allowed by the validating webhook:

apiVersion: snapshot.storage.k8s.io/v1
kind: VolumeSnapshot
metadata:
  name: new-snapshot-demo-v1
spec:
  volumeSnapshotClassName: csi-hostpath-snapclass-v1
  source:
    persistentVolumeClaimName: hpvc

Documentation and Resources

• Official Usage Guide
• Example Configs

What are Chainguard Containers?

Chainguard's free tier of Starter container images are built with Wolfi, our minimal Linux undistro.

All other Chainguard Containers are built with Chainguard OS, Chainguard's minimal Linux operating system designed to produce container images that meet the requirements of a more secure software supply chain.

The main features of Chainguard Containers include:

• Minimal design, without unnecessary software bloat
• Daily builds to ensure container images are up-to-date with available security patches
• High quality build-time SBOMs attesting to the provenance of all artifacts within the image
• Verifiable signatures provided by Sigstore
• Reproducible builds with Cosign and apko (read more about reproducibility)

For cases where you need container images with shells and package managers to build or debug, most Chainguard Containers come paired with a development, or -dev, variant.

In all other cases, including Chainguard Containers tagged as :latest or with a specific version number, the container images include only an open-source application and its runtime dependencies. These minimal container images typically do not contain a shell or package manager.

Although the -dev container image variants have similar security features as their more minimal versions, they include additional software that is typically not necessary in production environments. We recommend using multi-stage builds to copy artifacts from the -dev variant into a more minimal production image.

Need additional packages?

To improve security, Chainguard Containers include only essential dependencies. Need more packages? Chainguard customers can use Custom Assembly to add packages, either through the Console, chainctl, or API.

To use Custom Assembly in the Chainguard Console: navigate to the image you'd like to customize in your Organization's list of images, and click on the Customize image button at the top of the page.

Learn More

Refer to our Chainguard Containers documentation on Chainguard Academy. Chainguard also offers VMs and Libraries — contact us for access.

Trademarks

This software listing is packaged by Chainguard. The trademarks set forth in this offering are owned by their respective companies, and use of them does not imply any affiliation, sponsorship, or endorsement by such companies.