Play with terraform to deploy kubernetes cluster

Refs

• https://citycloud.com/devops/deploy-your-first-kubernetes-cluster-with-terraform-rke-and-manage-it-with-rancher
• https://www.itwonderlab.com/en/kubernetes-with-terraform/
• https://learn.hashicorp.com/tutorials/terraform/kubernetes-provider
• get started with terraform
• https://github.com/colinwilson/example-terraform-modules/tree/terraform-digitalocean-doks-harbor
• https://colinwilson.uk/2021/12/11/deploy-a-harbor-container-registry-with-high-availability-on-digitalocean-via-terraform/