Abstract

These are some tools to create a kubernetes cluster in Digitalocean.

• terraform creates the VMs
• kubeadm manages Kubernetes configuration
• ansible configures and runs kubeadm on the servers
• contiv for the network layer
• traefik as public proxy

Requirements

DigitalOcean account

• setup your info in tf_env.sh

terraform

• http://www.terraform.io/downloads.html
• https://www.digitalocean.com/community/tutorials/how-to-use-terraform-with-digitalocean

ansible

Using https://github.com/kairen/kubeadm-ansible

What it does

creates nodes on DO

Install kubeadm on them

• https://kubernetes.io/docs/setup/independent/create-cluster-kubeadm/
• https://kubernetes.io/docs/setup/independent/install-kubeadm/

and deploy kubernetes through kubeadm

Run

• ./genkey.sh # Only once, to generate the kube user key
• cd terraform
• ../gen_nodes_from_manager1.sh
• eval terraform plan $(../params.sh)
• eval terraform apply $(../params.sh)
• eval terraform destroy $(../params.sh)
• ../generate_inventory.sh > ../ansible/inventory
• cd ../ansible
• ansible-playbook -i inventory site.yml -u root

Connect

• ssh -i keys/kubekey kube@[manager IP]
• contiv is available on https://[manager]:10000/

Caveats

• kubeadm currently supports only one master, so this is not suitable for production

Todo

• auto-update Traefik conf (kubernetes provider?)
• Use Ansible dynamic inventory from tfstate
• Trigger Ansible from Terraform