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Air gap installation

This guide shows you how to install Kubewarden in air-gapped environments. For an air-gapped installation of Kubewarden, you need a private Open Container Initiative (OCI) registry accessible by your Kubernetes cluster. Kubewarden Policies are WebAssembly modules, therefore you can store them in an OCI-compliant registry as OCI artifacts. You need to add Kubewarden's images and policies to this OCI registry. The following sections describe the process.

Save container images in your workstation

  1. Download kubewarden-images.txt from the Kubewarden release page. Alternatively, the imagelist.txt and policylist.txt files are shipped inside the helm charts containing the used container images and policy Wasm modules, respectively.

    note

    Optionally, you can verify the signatures of the helm charts and container images

  2. Add cert-manager, if not available, to your private registry.

    helm repo add jetstack https://charts.jetstack.io
    helm repo update
    helm pull jetstack/cert-manager
    helm template ./cert-manager-<Version>.tgz | \
    awk '$1 ~ /image:/ {print $2}' | sed s/\"//g >> ./kubewarden-images.txt
  3. Download kubewarden-save-images.sh and kubewarden-load-images.sh from the utilities repository.

  4. Save Kubewarden container images into a .tar.gz file:

    ./kubewarden-save-images.sh \
    --image-list ./kubewarden-images.txt \
    --images kubewarden-images.tar.gz

    Docker begins pulling the images used for an air gap install. Be patient. This process takes a few minutes. When complete, your current directory, where you ran the command, has a tarball, kubewarden-images.tar.gz.

Save policies in your workstation

  1. Add all the policies you want to use in a policies.txt file. A file with a list of default policies is in the Kubewarden defaults release page.

  2. Download kubewarden-save-policies.sh and kubewarden-load-policies.sh from the kwctl repository

  3. Save policies into a .tar.gz file:

    ./kubewarden-save-policies.sh --policies-list policies.txt

    The policies are downloaded by kwctl and stored in the kubewarden-policies.tar.gz archive.

Helm charts

You need to download the following helm charts to your workstation:

helm pull kubewarden/kubewarden-crds
helm pull kubewarden/kubewarden-controller
helm pull kubewarden/kubewarden-defaults

Download cert-manager, if not installed, to the air gap cluster.

helm pull jetstack/cert-manager

Populate private registry

Move these files to the air gap environment:

  • kubewarden-policies.tar.gz,
  • kubewarden-images.tar.gz,
  • kubewarden-load-images.sh,
  • kubewarden-load-policies.sh and
  • policies.txt
  1. Load Kubewarden images into the private registry. The Docker client must be authenticated against the local registry.

    ./kubewarden-load-images.sh \
    --image-list ./kubewarden-images.txt \
    --images kubewarden-images.tar.gz \
    --registry <REGISTRY.YOURDOMAIN.COM:PORT>
  2. Load Kubewarden policies into the private registry. Kwctl must be authenticated against the local registry (kwctl uses the same mechanism to authenticate as docker, a ~/.docker/config.json file)

    ./kubewarden-load-policies.sh \
    --policies-list policies.txt \
    --policies kubewarden-policies.tar.gz \
    --registry <REGISTRY.YOURDOMAIN.COM:PORT> \
    --sources-path sources.yml
caution

The sources.yaml file is needed by kwctl to connect to registries in these categories:

  • Authentication is required
  • Self signed certificate is being used
  • No TLS termination is done

Please refer to the section on custom certificate authorities in the documentation to learn about configuring the sources.yaml file

Install Kubewarden

Now that your private registry has everything required you can install Kubewarden. The only difference to a standard Kubewarden installation is that you need to change the registry in the container images and policies to be the private registry.

Install cert-manager, if not already installed, in the air gap cluster:

helm install --create-namespace cert-manager ./cert-manager-<Version>.tgz \
-n kubewarden \
--set installCRDs=true \
--set image.repository=<REGISTRY.YOURDOMAIN.COM:PORT>/jetstack/cert-manager-controller \
--set webhook.image.repository=<REGISTRY.YOURDOMAIN.COM:PORT>/jetstack/cert-manager-webhook \
--set cainjector.image.repository=<REGISTRY.YOURDOMAIN.COM:PORT>/jetstack/cert-manager-cainjector \
--set startupapicheck.image.repository=<REGISTRY.YOURDOMAIN.COM:PORT>/jetstack/cert-manager-ctl

Now install the Kubewarden stack:

helm install --wait -n kubewarden \
kubewarden-crds kubewarden-crds.tgz
helm install --wait -n kubewarden \
kubewarden-controller kubewarden-controller.tgz \
--set global.cattle.systemDefaultRegistry=<REGISTRY.YOURDOMAIN.COM:PORT>
caution

To use the Policy Reported sub-chart available in the kubewarden-controller chart you need to define other values specific for the sub-chart in an air-gapped environment. See an example below:

helm install --wait -n kubewarden kubewarden-controller kubewarden-controller.tgz \
--set global.cattle.systemDefaultRegistry=<REGISTRY.YOURDOMAIN.COM:PORT> \
--set auditScanner.policyReporter=true \
--set policy-reporter.image.registry=<REGISTRY.YOURDOMAIN.COM:PORT> \
--set policy-reporter.ui.image.registry=<REGISTRY.YOURDOMAIN.COM:PORT> \
--set policy-reporter.image.repository=kyverno/policy-reporter \
--set policy-reporter.ui.image.repository=kyverno/policy-reporter-ui

It's necessary to define auditScanner.policyReporter to enable the sub-chart and 4 more values, to configure the registry and repository where the Policy Reporter images are stored. For more information about the policy report sub-chart values see chart repository.

helm install --wait -n kubewarden \
kubewarden-defaults kubewarden-defaults.tgz \
--set global.cattle.systemDefaultRegistry=<REGISTRY.YOURDOMAIN.COM:PORT>
caution

To download the recommended policies installed by the kubewarden-defaults Helm Chart from a registry other than global.cattle.systemDefaultRegistry, you can use the recommendedPolicies.defaultPoliciesRegistry configuration. This configuration lets users specify a registry dedicated to pulling the OCI artifacts of the policies. It's particularly useful when their container image repository doesn't support OCI artifacts.

To install, and wait for the installation to complete, use the following command:

helm install --wait -n kubewarden \
kubewarden-defaults kubewarden-defaults.tgz \
--set global.cattle.systemDefaultRegistry=<REGISTRY.YOURDOMAIN.COM:PORT> \
--set recommendedPolicies.defaultPoliciesRegistry=<REGISTRY.YOURDOMAIN.COM:PORT>

If the recommendedPolicies.defaultPoliciesRegistry configuration isn't set, the global.cattle.systemDefaultRegistry is used as the default registry.

Finally, you need to configure Policy Server to fetch policies from your private registry. See the using private registry section of the documentation.

Now you can create Kubewarden policies in your cluster. Policies must be available in your private registry.

kubectl apply -f - <<EOF
apiVersion: policies.kubewarden.io/v1
kind: ClusterAdmissionPolicy
metadata:
name: privileged-pods
spec:
module: registry://<REGISTRY.YOURDOMAIN.COM:PORT>/kubewarden/policies/pod-privileged:v0.2.2
rules:
- apiGroups: [""]
apiVersions: ["v1"]
resources: ["pods"]
operations:
- CREATE
mutating: false
EOF
caution

PolicyServer resources must use the image available in your private registry. For example:

apiVersion: policies.kubewarden.io/v1
kind: PolicyServer
metadata:
name: reserved-instance-for-tenant-a
spec:
image: <REGISTRY.YOURDOMAIN.COM:PORT>/kubewarden/policy-server:v1.3.0
replicas: 2
serviceAccountName: sa