Control Plane Setup Steps for CKA K8s Cluster

This page details the steps for setting up the control plane node in a Kubernetes cluster. It covers cluster initialization, obtaining the join command for worker nodes, and installing both the Calico network plugin and Metrics server.
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Prerequisites

  • Common Setup Steps for CKA K8s Cluster: This page outlines the essential setup steps for both master and worker nodes in a Kubernetes cluster. disable swap, load the required kernel modules, set the necessary system parameters, and install CRI-O runtime, Kubeadm, and related tools.

Cluster Initialization

To initialize your Kubernetes cluster, start by pulling the required container images:

sudo kubeadm config images pull

Next, set up environment variables to configure the cluster:

export C2_NODE_NAME=$(hostname -s)
export C2_CONTROL_IP="$(ip --json a s | jq -r '.[] | if .ifname == "eth1" then .addr_info[] | if .family == "inet" then .local else empty end else empty end')"
export C2_POD_CIDR=172.18.0.0/16
export C2_SERVICE_CIDR=172.17.1.0/18
env | grep C2_

Now, initialize the Kubernetes cluster with the following command:

kubeadm init --apiserver-advertise-address=$C2_CONTROL_IP \
  --apiserver-cert-extra-sans=$C2_CONTROL_IP \
  --pod-network-cidr=$C2_POD_CIDR \
  --service-cidr=$C2_SERVICE_CIDR \
  --node-name "$C2_NODE_NAME" \
  --ignore-preflight-errors Swap

Kube Config

As the user vagrant, follow this setup process.

Create the necessary Kube config directory and copy the admin configuration:

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
cp -i $HOME/.kube/config /vagrant/tmp/kubeconfig

Save Join Command

To simplify the process for worker nodes joining the cluster, save the join command to the /vagrant directory1.

kubeadm token create --print-join-command > /vagrant/tmp/join.sh

Install Calico Network Plugin

Download and install the Calico network plugin:

export CALICO_VERSION=v3.29.3
curl https://raw.githubusercontent.com/projectcalico/calico/${CALICO_VERSION}/manifests/calico.yaml -O

kubectl apply -f calico.yaml

Install Metrics Server

Finally, apply the Metrics Server manifest:

kubectl apply -f https://raw.githubusercontent.com/techiescamp/kubeadm-scripts/main/manifests/metrics-server.yaml

  1. Vagrant defaults to mounting the project directory containing the Vagrantfile inside each Vagrant box at the mount path /vagrant. This allows you to conveniently share files between the host and the Vagrant boxes. ↩︎


Last modified April 3, 2025: cka content C2-780 C2-781 (b5f908b)