A CKA lab for kubeadm with KVM/libvirt

This is an essential, quick&dirty (but complete) local lab to practice some kubeadm and etcdctl commands. More painful than minikube, but also more fun!

It has been built on a Fedora 37 + KVM and it's built on top of two components:

• virt-lightning, a simple but very effective way of spinning KVM VMs; it's tons faster than Vagrant and it has very little requirements; it also has an embedded function to produce an Ansible inventory. Head over to the virt-lightning README to learn more.

• ansible to install locally all dependencies and calling kubeadm (for both starting and configuring the master and joining the workers). This is executed from the host, and could/should have been put in form of roles. A few of these could/should have been cloud-init configs, but I focused on customizing rapidly rather than building efficiently. More on that in the README in the ansible dir

Running commands

Since I'm lazy and my shell history can only span a few thousand lines, I resorted to a few Taskfiles to call the usual commands:

❯ task
task: Available tasks for this project:
* cluster-access:                 Prints an export command to eval. Run "eval `task cluster-access`".
* cluster-info:                   Test access to the API Server
* local-setup:                    Install and configure the local workstation
* redo:                           Tear down and rebuild all lab
* ansible:playbook-init:          Prepare the OS
* ansible:playbook-kubeadm:       Bootstrap Kubernetes with kubeadm
* virt-lightning:create:          Create the lab machines
* virt-lightning:destroy:         Destroy the whole bunch of machines
* virt-lightning:start:           Start all VMs

Requirements

At the very minimum, you'll need:

• A fairly decent host (16 GB RAM and a quad-core CPU will do)
• Taskfiles and Kubectl binary in path. If you have asdf you can benefit from the local .tool-versions file.
• And of course, libvirt and the KVM implementation for your battle station, with a permissive sudoers

Everything else can be set up by calling task local-setup.