kro

packaged by Chainguard

Chainguard Container for kro

Minimal kro image for defining and managing groups of Kubernetes resources.

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/kro:latest

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

Compatibility Notes

The kro image is comparable to registry.k8s.io/kro/kro and preserves its /ko-app/controller entrypoint and command-line interface. It runs as UID 65532 by default instead of the upstream image's UID 0. The upstream Helm chart's UID 1000 security context is also supported.

Prerequisites

You need a Kubernetes cluster, Helm 3, kubectl, and permissions to install CRDs and cluster-wide RBAC. Configure the cluster to pull cgr.dev/ORGANIZATION/kro with your organization's registry credentials. See the upstream installation guide for supported deployment methods.

Getting Started

Replace ORGANIZATION with your registry organization, then create a values file that selects the Chainguard image:

cat > kro-values.yaml <<'EOF'
image:
  repository: cgr.dev/ORGANIZATION/kro
  tag: latest
EOF

helm install kro oci://registry.k8s.io/kro/charts/kro \
  --namespace kro-system --create-namespace \
  --values kro-values.yaml --wait

kubectl rollout status deployment/kro --namespace kro-system --timeout=180s
kubectl wait --for=condition=Established \
  crd/resourcegraphdefinitions.kro.run \
  crd/graphrevisions.internal.kro.run --timeout=60s

If your cluster uses an image pull secret, add its name to imagePullSecrets in the values file. To select a specific release, set image.tag to that release and pass the corresponding chart version with --version.

The controller is ready to reconcile resources. Follow the upstream ResourceGraphDefinition walkthrough to define an API, create an instance, and inspect the resources it manages.

Configuration

The chart configures /healthz and /readyz probes on port 8079. Use the chart values to configure leader election, resource limits, reconciliation concurrency, and image pull secrets.

Documentation and Resources

• kro documentation
• Upstream source
• Release notes

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.