====== Comprehensive Kubernetes Installation Guide (Ubuntu 24.04.3 LTS) ======

----
 
====== 1. System Update ======
<code>
sudo apt update && sudo apt upgrade -y
</code>
====== 2. Disable Swap ======
<code>
sudo swapoff -a
sudo sed -i '/ swap / s/^/#/' /etc/fstab
free -h
</code>
====== 3. Kernel Modules ======
<code>
cat <<EOF | sudo tee /etc/modules-load.d/k8s.conf
overlay
br_netfilter
EOF
sudo modprobe overlay
sudo modprobe br_netfilter
</code>

====== 4. Sysctl Configuration ======
<code>
cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-iptables=1
net.bridge.bridge-nf-call-ip6tables=1
net.ipv4.ip_forward=1
EOF
sudo sysctl --system
</code>

====== 5. Install containerd ======
<code>
sudo apt install -y containerd
sudo mkdir -p /etc/containerd
containerd config default | sudo tee /etc/containerd/config.toml
# Edit config:
# Set SystemdCgroup = true
sudo systemctl restart containerd
sudo systemctl enable containerd
</code>

====== 6. Install Kubernetes Components ======
<code>
sudo apt install -y apt-transport-https ca-certificates curl gpg
curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.29/deb/Release.key | \
sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] \
https://pkgs.k8s.io/core:/stable:/v1.29/deb/ /' | \
sudo tee /etc/apt/sources.list.d/kubernetes.list
sudo apt update
sudo apt install -y kubelet kubeadm kubectl
sudo apt-mark hold kubelet kubeadm kubectl
</code>

====== 7. Initialize Control Plane ======
<code>
sudo kubeadm init --pod-network-cidr=10.244.0.0/16
</code>

====== 8. Configure kubectl ======
<code>
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
kubectl get nodes
</code>

====== 9. Install Flannel Network ======
<code>
kubectl apply -f https://github.com/flannel-io/flannel/releases/latest/download/kube-flannel.yml
kubectl get pods -A
</code>

====== 10. Join Worker Nodes (Optional) ======
<code>
sudo kubeadm join <MASTER-IP>:6443 \
--token <TOKEN> \
--discovery-token-ca-cert-hash sha256:<HASH>
</code>

====== 11. Verify Cluster ======
<code>
kubectl get nodes -o wide
</code>

====== 12. Allow Pods on Control Plane (Optional) ======
<code>
kubectl taint nodes --all node-role.kubernetes.io/control-plane-
</code>

====== 13. Install Metrics Server (Optional) ======
<code>
kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.y
kubectl patch deployment metrics-server -n kube-system \
--type='json' \
-p='[{"op":"add","path":"/spec/template/spec/containers/0/args/-","value":"--kubelet-insecure-tls"}]'
</code>

====== 14. Troubleshooting ======

Check pods:
<code>
kubectl get pods -A
</code>
Check container runtime:
<code>
crictl info
</code>
Ensure CRDs installed before apps like Traefik/MetalLB.