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Customizing Cluster Components

Most cluster components of Kube-Hetzner are deployed with the Rancher Helm Chart yaml definition and managed by the Helm Controller inside k3s.

By default, we strive to give you optimal defaults, but if you wish, you can customize them.

Helm Values Customization​

For Traefik, Nginx, HAProxy, Rancher, Cilium, Traefik, and Longhorn, for maximum flexibility, we give you the ability to configure them even better via helm values variables (e.g. cilium_values, see the advanced section in the kube.tf.example for more).

Example: Customizing Traefik​

traefik_values = <<EOT
ports:
  web:
    nodePort: 32080
  websecure:
    nodePort: 32443
providers:
  kubernetesIngress:
    publishedService:
      enabled: true
EOT

Example: Customizing Longhorn​

longhorn_values = <<EOT
defaultSettings:
  backupTarget: "s3://backup-bucket@us-east-1/"
  backupTargetCredentialSecret: "aws-secret"
persistence:
  dataPath: "/var/lib/longhorn"
EOT

Using Additional Manifests​

If you need to install additional Helm charts or Kubernetes manifests that are not provided by default, you can easily do so by using Kustomize. This is done by creating one or more extra-manifests/kustomization.yaml.tpl files beside your kube.tf.

If you'd like to use a different folder name, you can configure it using the extra_kustomize_folder variable. By default, it is set to extra-manifests. This can be useful when working with multiple environments, allowing you to deploy different manifests for each one.

These files need to be valid Kustomization manifests, additionally supporting terraform templating! (The templating parameters can be passed via the extra_kustomize_parameters variable (via a map) to the module).

All files in the extra-manifests directory and its subdirectories including the rendered versions of the *.yaml.tpl will be applied to k3s with kubectl apply -k (which will be executed after and independently of the basic cluster configuration).

Post-Install Actions​

After the initial bootstrapping of your Kubernetes cluster, you might want to deploy applications using the same terraform mechanism. For many scenarios it is sufficient to create a kustomization.yaml.tpl file (see Adding Extras). All applied kustomizations will be applied at once by executing a single kubectl apply -k command.

However, some applications that e.g. provide custom CRDs (e.g. ArgoCD) need a different deployment strategy: one has to deploy CRDs first, then wait for the deployment, before being able to install the actual application. In the ArgoCD case, not waiting for the CRD setup to finish will cause failures. Therefore, an additional mechanism is available to support these kind of deployments. Specify extra_kustomize_deployment_commands in your kube.tf file containing a series of commands to be executed, after the Kustomization step finished:

extra_kustomize_deployment_commands = <<-EOT
  kubectl -n argocd wait --for condition=established --timeout=120s crd/appprojects.argoproj.io
  kubectl -n argocd wait --for condition=established --timeout=120s crd/applications.argoproj.io
  kubectl apply -f /var/user_kustomize/argocd-projects.yaml
  kubectl apply -f /var/user_kustomize/argocd-application-argocd.yaml
EOT