Kubernetes Cluster

Create a kubernetes cluster from scratch with multipass vms and ansible.

A) Create the ubuntu vms with multipass

To create the vms run the up script (./up)

This script will:

• Create and start 3 vms (with names kube-node-0, kube-node-1, kube-node-2)
• Add the public key ./keys/key.pub in each vm's authorized_keys
• Create the ansible inventory file by getting each vm's ip.

B) Create kubernetes cluster with ansible

Every ansible playbook must be run from ./ansible directory (cd ansible).

Install ansible and virtual environment

• Create and activate virtual env (optional)

python3 -m venv --clear ./venv
source ./venv/bin/activate
pip install -U pip setuptools wheel # Optionally

• Install ansible and tools

pip install -U ansible-core ansible ansible-lint ansible-navigator

• ./bin/install-ansible-collections-and-roles Installs ansible collections and roles.
• ./bin/ansible-playbook 00-requirements.yml Installs basic configuration requirements for each node.
• ./bin/ansible-playbook 01-crio.yml Installs cri-o as container runtime
• ./bin/ansible-playbook 02-kube-install.yml Installs kubernetes deployment tools (kubeadm, kubelet, kubectl).
• ./bin/ansible-playbook 03-kube-cluster.yml Setups the kubernetes cluster into the first node kube-node-0.
• (cni option 1) ./bin/ansible-playbook 04-cilium.yml Setups cilium (cni) networking add-on.
• (cni option 2) ./bin/ansible-playbook 04-calico.yml Setups calico (cni) networking add-on.
• ./bin/ansible-playbook 05-kube-join-nodes.yml Joins the rest vms to kubernetes cluster as nodes.

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Access cluster

A) From kube-node-0 (multipass shell kube-node-0)

You can access kubernetes cluster through kube-node-0 by opening a shell to it with multipass shell kube-node-0.

multipass shell kube-node-0
kubectl get nodes

B) From host (get .kube/config from kube-node-0)

You can access the cluster directly with kubectl from the host machine by getting the ~/.kube/config from kube-node-0

mkdir -p ~/.kube/
multipass transfer kube-node-0:/home/ubuntu/.kube/config - > ~/.kube/config
kubectl get nodes