Install K8s Master/Worker

Step-by-Step Instructions to Install Kubernetes

1. Prerequisites

• Ensure you are using Ubuntu (tested on Ubuntu 18.04/20.04).

• You need root or sudo access on all nodes.

2. Update and Upgrade the System

On all nodes (master and workers), update and upgrade the system:

sudo apt update
sudo apt upgrade -y

3. Disable Swap

On all nodes, disable swap:

sudo swapoff -a
sudo sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab

4. Configure Kernel Parameters

On all nodes, load necessary kernel modules and configure sysctl:

sudo tee /etc/modules-load.d/containerd.conf <<EOF
overlay
br_netfilter
EOF

sudo modprobe overlay
sudo modprobe br_netfilter

sudo tee /etc/sysctl.d/kubernetes.conf <<EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
EOF

sudo sysctl --system

5. Install Containerd Runtime

On all nodes, install Containerd:

sudo apt install -y curl gnupg2 software-properties-common apt-transport-https ca-certificates
sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmour -o /etc/apt/trusted.gpg.d/docker.gpg
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
sudo apt update
sudo apt install -y containerd.io

containerd config default | sudo tee /etc/containerd/config.toml >/dev/null 2>&1
sudo sed -i 's/SystemdCgroup \= false/SystemdCgroup \= true/g' /etc/containerd/config.toml
sudo systemctl restart containerd
sudo systemctl enable containerd

6. Add Kubernetes Repository and Install Components

On all nodes, add the Kubernetes repository and install kubelet, kubeadm, and kubectl:

sudo apt-get update
sudo apt-get install -y apt-transport-https ca-certificates curl gnupg

curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.29/deb/Release.key | sudo gpg --dearmor -o /etc/apt/trusted.gpg.d/kubernetes-apt-keyring.gpg

echo 'deb [signed-by=/etc/apt/trusted.gpg.d/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.29/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list

sudo apt-get update
sudo apt-get install -y kubelet kubeadm kubectl
sudo apt-mark hold kubelet kubeadm kubectl

sudo systemctl enable --now kubelet

7. Initialize the Master Node

On the master node, initialize the Kubernetes cluster:

sudo kubeadm init

Set up kubeconfig for the current user:

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

Install the Calico network plugin:

kubectl apply -f https://raw.githubusercontent.com/projectcalico/calico/v3.25.0/manifests/calico.yaml

8. Join Worker Nodes to the Cluster

On each worker node, run the kubeadm join command provided by the master node during initialization. Replace <master-node-ip>, <port>, <token>, and <hash> with the actual values:

kubeadm join <master-node-ip>:<port> --token <token> --discovery-token-ca-cert-hash <hash>

9. Deploy a Test Application (Optional)

To deploy a test application (e.g., nginx) on the master node:

kubectl run nginx --image=nginx

Summary

1. Update and upgrade all nodes.

2. Disable swap on all nodes.

3. Configure kernel parameters on all nodes.

4. Install Containerd runtime on all nodes.

5. Add Kubernetes repository and install kubelet, kubeadm, and kubectl on all nodes.

6. Initialize the master node.

7. Join worker nodes to the cluster.

8. (Optional) Deploy a test application.