Kubernetes lab for CKA study

This is a simple set of configurations, Ansible tasks & playbooks to deploy & manage virtual machines for the purposes of studying for the CKA exam.

Targeting the current CKA exam version of Kubernetes, v1.24.4.

Topology

32GB + Intel Xeon E1231v3 CPU on the host machine.

Six (6) virtual machines act as the cluster.

Three (3) Ubuntu 22.04 VMs acting as cluster control plane nodes and stacked etcd. 3GB/2CPU
- kubeadm, kubelet and kubectl
- keepalived + haproxy for high availability. See options for software load balancing for details.
Three (3) Ubuntu 22.04 VMs acting as worker nodes. 2GB/2CPU
- kubelet

Each server has two NICs, one host-only private network (192.168.56.0/24) and the other bridged to the host for Internet access (192.168.1.0/24).

An additional VM is used as an Ansible control host and development.

Usage

It's assumed that you have a valid Ansible inventory specified in /etc/ansible/hosts with two groups, controlplane and nodes. There is also a provided hosts file that can be specified with the -i option.

[kubernetes]
ubuntu0[1:6].lab

[controlplane]
ubuntu0[1:3].lab

[nodes]
ubuntu0[4:6].lab

I'm also using the common role to configure the /etc/hosts file for internal name resolution.

Playbook follows the kubeadm installation instructions found here: https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/

$ ansible-playbook -i inventory/hosts site.yaml

Upgrades

The following tags can be used to upgrade specific components and remove dpkg hold.

Note: This playbook does not drain any nodes of active pods.

To upgrade a cluster:

Change kubernetes_version in group_vars/all or set it via extra-args.

Run kubeadm & kubectl upgrades on a control plane node. Use --limit <nodename> to choose which one to perform the upgrade on.

ansible-playbook -i inventory/hosts site.yaml --tags "upgrade,kubeadm,kubectl" --limit ubuntu01.lab
ansible-playbook -i inventory/hosts site.yaml --tags "upgrade,kubeadm,kubectl" --limit ubuntu02.lab
ansible-playbook -i inventory/hosts site.yaml --tags "upgrade,kubeadm,kubectl" --limit ubuntu03.lab

Upgrade the kubectl on the control plane nodes.

ansible-playbook -i inventory/hosts site.yaml --tags "upgrade,kubelet" --limit "controlplane"

Drain the nodes.

ansible nodes -i inventory/hosts --become -a 'kubectl drain $(hostname)'

Upgrade the nodes.

ansible-playbook -i inventory/hosts site.yaml --tags "upgrade,kubeadm,kubectl,kubelet" --limit "nodes"

Uncordon the nodes.

ansible nodes -i inventory/hosts --become -a 'kubectl uncordon $(hostname)'

Rest

Use kubeadm reset via ansible ad-hoc to completely reset a cluster node.

ansible kubernetes --become -i inventory/hosts -a 'kubeadm reset -f --ignore-preflight-errors all'

coopernetes/cka-lab-environment

ErrorLooks like something went wrong!

About

Resources

Uh oh!

Stars

Watchers

Forks

Releases

Packages 0

Languages

Error
Looks like something went wrong!

Packages