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Adding Extras

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.

Directory Structure​

Create an extra-manifests directory in your project folder:

your-project/
├── kube.tf
└── extra-manifests/
    ├── kustomization.yaml.tpl
    ├── deployment.yaml
    └── service.yaml

Kustomization Template​

Create a kustomization.yaml.tpl file in your extra-manifests directory:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

resources:
- deployment.yaml
- service.yaml

configMapGenerator:
- name: app-config
  literals:
    - APP_ENV=production
    - DATABASE_URL=${database_url}

Note the ${database_url} variable which can be passed through Terraform.

Passing Template Variables​

You can pass variables to your kustomization templates using the extra_kustomize_parameters variable:

extra_kustomize_parameters = {
  database_url = "postgresql://user:pass@db:5432/myapp"
  app_version  = "v1.2.3"
}

Custom Folder Name​

If you'd like to use a different folder name, you can configure it using the extra_kustomize_folder variable:

extra_kustomize_folder = "my-custom-manifests"

This can be useful when working with multiple environments, allowing you to deploy different manifests for each one.

Advanced Deployment Commands​

For applications that require custom deployment steps (like waiting for CRDs), you can specify extra_kustomize_deployment_commands:

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
EOT

Helm Charts with Kustomize​

You can also use Kustomize to deploy Helm charts:

# kustomization.yaml.tpl
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

helmCharts:
- name: prometheus
  repo: https://prometheus-community.github.io/helm-charts
  version: 15.0.0
  releaseName: prometheus
  namespace: monitoring
  valuesFile: prometheus-values.yaml

Terraform Integration​

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).