Private Registries and Air-Gapped Deployments

Some environments restrict access to public container registries like ghcr.io and docker.io. In these cases, you need to mirror the required container images to your private registry before deploying.

This guide covers how to mirror the images required by the wasmCloud Helm chart and configure the deployment to use your private registry.

Required images

The wasmCloud runtime-operator Helm chart uses the following container images:

Image	Component
ghcr.io/wasmcloud/runtime-operator:<version>	Operator
ghcr.io/wasmcloud/runtime-gateway:<version>	Gateway
ghcr.io/wasmcloud/wash:<version>	Runtime host
docker.io/nats:<nats-version>	NATS server (optional)

tip

To find the exact image tags for a given chart version, run:

shell

helm show values oci://ghcr.io/wasmcloud/charts/runtime-operator --version <version>

For example, with version 2.0.0-rc.7, the images are:

• ghcr.io/wasmcloud/runtime-operator:2.0.0-rc.7
• ghcr.io/wasmcloud/runtime-gateway:2.0.0-rc.7
• ghcr.io/wasmcloud/wash:2.0.0-rc.7
• docker.io/nats:2.11.3-alpine

If you disable the built-in NATS server (--set nats.enabled=false), you do not need to mirror the NATS image.

Mirror images to your registry

Prerequisites

• oras CLI
• yq and jq
• Authenticated to both the source registries (ghcr.io, docker.io) and your destination registry

Create an image manifest

Create a mirror.yaml file listing the source and destination for each image. Replace myregistry with your private registry:

yaml

images:
  # wasmCloud runtime images
  - source: ghcr.io/wasmcloud/runtime-operator:2.0.0-rc.7
    destination: myregistry/wasmcloud/runtime-operator:2.0.0-rc.7
  - source: ghcr.io/wasmcloud/runtime-gateway:2.0.0-rc.7
    destination: myregistry/wasmcloud/runtime-gateway:2.0.0-rc.7
  - source: ghcr.io/wasmcloud/wash:2.0.0-rc.7
    destination: myregistry/wasmcloud/wash:2.0.0-rc.7

  # Third-party images
  - source: docker.io/nats:2.11.3-alpine
    destination: myregistry/nats:2.11.3-alpine

Run the mirror script

Create and run mirror.sh:

bash

#!/bin/bash
CONFIG_FILE="mirror.yaml"

if ! command -v oras >/dev/null 2>&1; then
  echo "oras not found. Please install: https://oras.land"
  exit 1
fi

echo "Mirroring images from $CONFIG_FILE..."
yq -o=json e '.images[]' "$CONFIG_FILE" | jq -c '.' | while read -r line; do
    src=$(echo "$line" | jq -r '.source')
    dst=$(echo "$line" | jq -r '.destination')
    if [[ -n "$src" && -n "$dst" && "$dst" != "null" ]]; then
      echo "Copying $src -> $dst"
      oras copy "$src" "$dst"
    fi
done

shell

chmod +x ./mirror.sh
./mirror.sh

Deploy with your private registry

The Helm chart provides a global.image.registry value that overrides the registry for all component images at once.

Basic install with global registry override

shell

helm install wasmcloud-runtime oci://ghcr.io/wasmcloud/charts/runtime-operator \
  --version 2.0.0-rc.7 \
  --namespace wasmcloud \
  --create-namespace \
  --set global.image.registry="myregistry"

With an image pull secret

If your private registry requires authentication, create a Kubernetes pull secret and reference it in the Helm install:

shell

kubectl create namespace wasmcloud

kubectl create secret docker-registry my-registry-secret \
  --namespace wasmcloud \
  --docker-server=myregistry \
  --docker-username=<username> \
  --docker-password=<password>

Then install with the pull secret:

shell

helm install wasmcloud-runtime oci://ghcr.io/wasmcloud/charts/runtime-operator \
  --version 2.0.0-rc.7 \
  --namespace wasmcloud \
  --create-namespace \
  --set global.image.registry="myregistry" \
  --set global.image.pullSecrets[0].name="my-registry-secret"

Per-component registry overrides

If you need to mirror images to different registry paths, you can override each component individually:

shell

helm install wasmcloud-runtime oci://ghcr.io/wasmcloud/charts/runtime-operator \
  --version 2.0.0-rc.7 \
  --namespace wasmcloud \
  --create-namespace \
  --set operator.image.registry="myregistry" \
  --set gateway.image.registry="myregistry" \
  --set runtime.image.registry="myregistry" \
  --set nats.image.registry="myregistry"

Rendering manifests with helm template

If your organization uses a GitOps workflow or requires manifests to be reviewed before applying, you can use helm template to render the Kubernetes manifests locally without installing anything to the cluster.

Render to stdout

shell

helm template wasmcloud-runtime oci://ghcr.io/wasmcloud/charts/runtime-operator \
  --version 2.0.0-rc.7 \
  --namespace wasmcloud \
  --set global.image.registry="myregistry" \
  --set global.image.pullSecrets[0].name="my-registry-secret"

Render to a directory

Write the rendered manifests to a directory for review or to check into version control:

shell

helm template wasmcloud-runtime oci://ghcr.io/wasmcloud/charts/runtime-operator \
  --version 2.0.0-rc.7 \
  --namespace wasmcloud \
  --set global.image.registry="myregistry" \
  --set global.image.pullSecrets[0].name="my-registry-secret" \
  --output-dir ./wasmcloud-manifests

This creates a wasmcloud-manifests/ directory with one file per Kubernetes resource. You can then apply them with:

shell

kubectl apply --recursive -f ./wasmcloud-manifests

Verify image references

After rendering, you can verify that all image references point to your private registry:

shell

helm template wasmcloud-runtime oci://ghcr.io/wasmcloud/charts/runtime-operator \
  --version 2.0.0-rc.7 \
  --namespace wasmcloud \
  --set global.image.registry="myregistry" \
  | grep "image:"

You should see all images prefixed with your registry and no references to ghcr.io or docker.io.

Use a values file

For repeatable deployments, store your overrides in a values file rather than passing --set flags:

yaml

global:
  image:
    registry: myregistry
    pullSecrets:
      - name: my-registry-secret

Then reference it with -f:

shell

helm template wasmcloud-runtime oci://ghcr.io/wasmcloud/charts/runtime-operator \
  --version 2.0.0-rc.7 \
  --namespace wasmcloud \
  -f my-values.yaml

This same values file works with helm install and helm upgrade.

Using Kustomize?

If your team uses Kustomize to manage Kubernetes manifests, you can combine it with helm template. Render the chart to a directory as shown above, then use Kustomize to apply additional patches, labels, or transformations on top of the rendered output. For example, you can use a Kustomize images transformer to rewrite image references, or layer environment-specific overlays on top of a shared base.

A minimal setup looks like:

yaml

resources:
  - ./wasmcloud-manifests/runtime-operator/templates

images:
  - name: ghcr.io/wasmcloud/runtime-operator
    newName: myregistry/wasmcloud/runtime-operator
  - name: ghcr.io/wasmcloud/runtime-gateway
    newName: myregistry/wasmcloud/runtime-gateway
  - name: ghcr.io/wasmcloud/wash
    newName: myregistry/wasmcloud/wash
  - name: docker.io/nats
    newName: myregistry/nats

shell

kubectl apply -k .

This approach is particularly useful when you need to manage multiple environments (staging, production) with different registries or configurations.

Helm values reference

These are the image-related values you can configure:

Value	Default	Description
global.image.registry	""	Override registry for all images
global.image.pullSecrets	[]	Global image pull secrets
operator.image.registry	ghcr.io	Operator image registry
operator.image.repository	wasmcloud/runtime-operator	Operator image repository
operator.image.tag	Chart appVersion	Operator image tag
gateway.image.registry	ghcr.io	Gateway image registry
gateway.image.repository	wasmcloud/runtime-gateway	Gateway image repository
runtime.image.registry	ghcr.io	Runtime host image registry
runtime.image.repository	wasmcloud/wash	Runtime host image repository
runtime.image.tag	2.0.0-rc.7	Runtime host image tag
nats.image.registry	docker.io	NATS image registry
nats.image.repository	nats	NATS image repository
nats.image.tag	2.11.3-alpine	NATS image tag