K3s on Libvirt Quickstart

Setting up extra terraform provider

Due to an issue in the terraform provider system, you need to download and place the libvirt provider at a very specific location in your home directory before deploying K3s. You can find the libvirt provider version in modules/k3s/libvirt/versions.tf. To keep things simple this version will be referred to as $LIBVIRT_PROVIDER_VERSION in this documentation. Go to https://github.com/dmacvicar/terraform-provider-libvirt/releases/tag/v$LIBVIRT_PROVIDER_VERSION and find the correct link for your OS/CPU_ARCH (an example is linux_amd64, referred to as $OS_CPU_ARCH in the rest of this documentation). 
mkdir -p ~/.local/share/terraform/plugins/registry.terraform.io/dmacvicar/libvirt/$LIBVIRT_PROVIDER_VERSION/$OS_CPU_ARCH/
mv terraform-provider-libvirt ~/.local/share/terraform/plugins/registry.terraform.io/dmacvicar/libvirt/$LIBVIRT_PROVIDER_VERSION/$OS_CPU_ARCH/terraform-provider-libvirt
shell

Prerequisites

  • Access to a functional Libvirt daemon

  • Knowledge of Terraform basics

Create the Terraform root module

module "cluster" {
  source = "git::https://github.com/camptocamp/camptocamp-devops-stack.git//modules/k3s/libvirt?ref=master"

  cluster_name = "my-cluster"
  node_count   = 2
}
hcl

Terraform Outputs

Define outputs:

# terraform/outputs.tf

output "argocd_auth_token" {
  sensitive = true
  value     = module.cluster.argocd_auth_token
}

output "kubeconfig" {
  sensitive = true
  value     = module.cluster.kubeconfig
}

output "repo_url" {
  value = module.cluster.repo_url
}

output "target_revision" {
  value = module.cluster.target_revision
}

output "app_of_apps_values" {
  sensitive = true
  value     = module.cluster.app_of_apps_values
}
hcl

Deploy the cluster

$ terraform init
$ terraform apply
shell

You should see the services URL as Terraform outputs.

Retrieve kubeconfig

$ terraform output -json kubeconfig | jq -r .
shell

Destroy the cluster

$ terraform destroy
shell