Kubernetes-on-Multipass

Ansible playbook for spinning up a Kubernetes cluster (HA or non-HA) on multipass ubuntu VMs

High level overview

• Use ansible to create a number of multipass VMs
• Check out multipass refence documentation for more details on commands used
• Use kubeadm to orchestrate a kubernetes cluster on the VMs as control and worker nodes
• Use kubectl to interact with the cluster

How it works

• What's in the /create directory?

  1. contains configurations to create all the nodes needed for a kubernetes cluster, including control, worker, and load balancer (if cluster is HA) nodes
  2. cloud-init-template.j2: multipass supports cloud-init, this template is used to create the worker VMs cloud-init config file
  3. create-vm-tasks.yaml: tasks to create the nodes according to config file and creates an inventory file to be consumed in a different ansible play
  4. install-packages-tasks.yaml: tasks to install & configure apt packages needed for the node
  5. join-cluster-tasks.yaml: tasks to configure & join nodes to the cluster
  6. playbook.yaml: the main ansible playbook - parses the config file, executes tasks in create-vm-tasks.yaml and run plays from other playbooks to configure an HA k8s cluster
  7. vars.yaml: contains all the variables
  8. /control - contains configurations to initialize and configure control plane nodes
  9. /loadbalancer - contains configurations to configure load balancer node

• What's in the /control directory?

  1. init-first-ctrl-node-tasks.yaml: tasks to initialize the cluster, configure the control nodes
  2. kubeadm-config-template.j2: template for kubeadm config file

• What's in the /loadbalancer directory?

  1. cloud-init-template.j2: multipass supports cloud-init, this template is used to create the cloud-init config file
  2. haproxy-cfg-template.j2: template for haproxy config file
  3. configure-lb-tasks.yaml: tasks to configure the haproxy load balancer config

• What's in the /inventories directory?

  1. control.yaml: inventory file for control nodes
  2. loadbalancer.yaml: inventory file for load balancer nodes
  3. worker.yaml: inventory file for worker nodes

• What's in the /upgrade directory?

  1. upgrade-node-tasks.yaml: tasks to upgrade the control nodes
  2. playbook.yaml: playbook that calls playbooks from /control and worker

Prerequisites

• Install multipass
• Install ansible

Create a kubernetes cluster

• How to create a kubernetes cluster

  1. run ansible-playbook create/playbook.yaml

• How to upgrade a kubernetes cluster

  1. run ansible-playbook upgrade/playbook.yaml

• How to delete the cluster

  1. run multipass stop --all to stop all the multipass VMs
  2. run multipass delete -all to delete all the multipass VMs. ❗ FYI: will DELETE all multipass VMs ❗
  3. run multipass purge to purge the VMs