Create Kubernetes cluster with Kubespray

For an High Availability control plane, 3 hosts are required with the following requirements:

• 16G RAM

• 100 GB DISK

• 6 CPU cores

First, provision the hosts OS with Ubuntu 22.04.

For the installation of Kubernetes, Kubespray can be used. See this link for extended instructions.

Since Kubespray is using Ansible an additional machine is needed to run it.

It is recommended to copy the machine’s public SSH key to the hosts with ssh-copy-id.

Read the following section regarding the needed libraries for Ansible and other requirements.

Clone the Kubespray GitHub repository.

            

            
git clone https://github.com/kubernetes-sigs/kubespray.git
cd kubespray
git checkout release-2.20
        

Create an inventory file for Ansible. (See more details here).

In the following example, the HOST_PREFIX will set the nodes name prefix to dcmp-cp- and KUBE_CONTROL_HOSTS will mark all 3 nodes to be control nodes.

            

            
cp -r inventory/sample inventory/mycluster
declare -a IPS=(10.10.1.3 10.10.1.4 10.10.1.5)
HOST_PREFIX=dcm-cp- KUBE_CONTROL_HOSTS=3 CONFIG_FILE=inventory/mycluster/hosts.yaml python3 contrib/inventory_builder/inventory.py ${IPS[@]}
        

Customize following variables in inventory/mycluster/group_vars/k8s_cluster/k8s-cluster.yml:

            

            
# Make a copy of kubeconfig on the host that runs Ansible in {{ inventory_dir }}/artifacts
kubeconfig_localhost: true
kube_network_plugin: flannel
        

For OVN-Kubernetes, specify kube_network_plugin: cni to prevent Kubespray from installing any CNI. Otherwise, use kube_network_plugin: flannel

For high availability , configuring a VIP and load balancer is required. See instructions.

Here a sample configuration:

In inventory/mycluster/group_vars/k8s_cluster/k8s-cluster.yml, set:

            

            
kube_proxy_strict_arp: true
        

In inventory/mycluster/group_vars/all/all.yml, set: (Make sure to update values with correct VIP and interface)

            

            
kube_vip_arp_enabled: true
kube_vip_enabled: true
kube_vip_controlplane_enabled: true
kube_vip_address: 10.7.12.250 # update with correct VIP
kube_vip_interface: eno1      # update with correct interface
kube_vip_services_enabled: false
loadbalancer_apiserver:
  address: "{{ kube_vip_address }}"
  port: 6443
        

            

            
sudo ansible-playbook --flush-cache -T 30 -i inventory/mycluster/hosts.yaml cluster.yml --become --become-user=root --private-key=~/.ssh/private_key
        

A copy of the Kubeconfig file will be available in inventory/mycluster/artifacts/admin.conf.

            

            
kubectl -n kube-system patch ds kube-flannel-ds-arm64 --type "json" -p '[{"op":"add","path":"/spec/template/spec/initContainers/0/image","value":"docker.io/flannelcni/flannel-cni-plugin:v1.1.0-arm64"}]'