Customization

Customize the Helm chart deployment of Confidential Containers

Categories:

The Helm chart can be customized by passing additional parameters to the helm install command.

Important Notes

Node Selectors: When setting node selectors with dots in the key, escape them: node-role\.kubernetes\.io/worker
Namespace: All examples use coco-system namespace. Adjust as needed for your environment
Architecture: The default architecture is x86_64. Other architectures must be explicitly specified
Comma Escaping: When using --set with values containing commas, escape them with \,

Customizing deployment

You can combine architecture values files (with -f) and/or with --set flags for customizations.

Using `--set` flags

To customize the installation using --set flags, run one of the following commands based on your architecture:

# For x86_64

helm install coco oci://ghcr.io/confidential-containers/charts/confidential-containers \
  --set kata-as-coco-runtime.debug=true \
  --namespace coco-system \
  --create-namespace

# For s390x

helm install coco oci://ghcr.io/confidential-containers/charts/confidential-containers \
  -f https://raw.githubusercontent.com/confidential-containers/charts/main/values/kata-s390x.yaml \
  --set kata-as-coco-runtime.debug=true \
  --namespace coco-system \
  --create-namespace

Parameters that are commonly customized (use --set flags):

Parameter	Description	Default
`kata-as-coco-runtime.imagePullPolicy`	Image pull policy	`Always`
`kata-as-coco-runtime.imagePullSecrets`	Image pull secrets for private registry	`[]`
`kata-as-coco-runtime.k8sDistribution`	Kubernetes distribution (k8s, k3s, rke2, k0s, microk8s)	`k8s`
`kata-as-coco-runtime.nodeSelector`	Node selector for deployment	`{}`
`kata-as-coco-runtime.debug`	Enable debug logging	`false`

Structured Configuration (Kata Containers)

The chart uses Kata Containers’ structured configuration format for TEE shims. Parameters set by architecture-specific kata runtime values files:

Parameter	Description	Set by values/kata-*.yaml
`architecture`	Architecture label for NOTES	`x86_64` or `s390x`
`kata-as-coco-runtime.snapshotter.setup`	Array of snapshotters to set up (e.g., `["nydus"]`)	Architecture-specific
`kata-as-coco-runtime.shims.<shim-name>.enabled`	Enable/disable specific shim (e.g., `qemu-snp`, `qemu-tdx`, `qemu-se`, `qemu-coco-dev`)	Architecture-specific
`kata-as-coco-runtime.shims.<shim-name>.supportedArches`	List of architectures supported by the shim	Architecture-specific
`kata-as-coco-runtime.shims.<shim-name>.containerd.snapshotter`	Snapshotter to use for containerd (e.g., `nydus`, `""` for none)	Architecture-specific
`kata-as-coco-runtime.shims.<shim-name>.containerd.forceGuestPull`	Enable experimental force guest pull	`false`
`kata-as-coco-runtime.shims.<shim-name>.crio.guestPull`	Enable guest pull for CRI-O	Architecture-specific
`kata-as-coco-runtime.shims.<shim-name>.agent.httpsProxy`	HTTPS proxy for guest agent	`""`
`kata-as-coco-runtime.shims.<shim-name>.agent.noProxy`	No proxy settings for guest agent	`""`
`kata-as-coco-runtime.runtimeClasses.enabled`	Create runtimeclass resources	`true`
`kata-as-coco-runtime.runtimeClasses.createDefault`	Create default k8s runtimeclass	`false`
`kata-as-coco-runtime.runtimeClasses.defaultName`	Name for default runtimeclass	`"kata"`
`kata-as-coco-runtime.defaultShim.<arch>`	Default shim per architecture (e.g., `amd64: qemu-snp`)	Architecture-specific

Additional Parameters (kata-deploy options)

These inherit from kata-deploy defaults but can be overridden:

Parameter	Description	Default
`kata-as-coco-runtime.image.reference`	Kata deploy image	`quay.io/kata-containers/kata-deploy`
`kata-as-coco-runtime.image.tag`	Kata deploy image tag	Chart’s application version
`kata-as-coco-runtime.env.installationPrefix`	Installation path prefix	`""` (uses kata-deploy defaults)
`kata-as-coco-runtime.env.multiInstallSuffix`	Suffix for multiple installations	`""`

See quickstart for complete customization examples and usage.

Using file based values

Prepare my-values.yaml file in one of the following ways:

Using latest default values downloaded from the chart:

helm show values oci://ghcr.io/confidential-containers/charts/confidential-containers > my-values.yaml

Using newly created file my-values.yaml with your customizations, e.g., for s390x with debug and node selector:

architecture: s390x

kata-as-coco-runtime:
  env:
    debug: "true"
    shims: "qemu-coco-dev qemu-se"
    snapshotterHandlerMapping: "qemu-coco-dev:nydus,qemu-se:nydus"
    agentHttpsProxy: "http://proxy.example.com:8080"
  nodeSelector:
    node-role.kubernetes.io/worker: ""

List of custom values examples can be found in the examples-custom-values.

Install chart using your custom values file:

helm install coco oci://ghcr.io/confidential-containers/charts/confidential-containers \
  -f my-values.yaml \
  --namespace coco-system \
  --create-namespace

Multiple combined customization options

Customizations using --set flags can be combined with file based values using -f.

See below example which will provide s390x architecture, enable debug logging, and set a node selector for worker nodes.

helm install coco oci://ghcr.io/confidential-containers/charts/confidential-containers \
  -f https://raw.githubusercontent.com/confidential-containers/charts/main/values/kata-s390x.yaml \
  --set kata-as-coco-runtime.env.debug=true \
  --set kata-as-coco-runtime.nodeSelector."node-role\.kubernetes\.io/worker"="" \
  --set kata-as-coco-runtime.k8sDistribution=k3s \
  --namespace coco-system \
  --create-namespace

Last modified January 20, 2026: docs: Updated installation using helm charts (8d869a4)