Update and upgrade

sudo apt update && sudo apt upgrade -y
sudo apt install -y curl gnupg apt-transport-https ca-certificates lsb-release

Hostname

sudo hostnamectl set-hostname k8s-cp-01
sudo hostnamectl set-hostname k8s-node-01

IP

sudo nano /etc/network/interfaces

auto eth0
iface eth0 inet static
    address 172.31.71.121
    netmask 255.255.240.0
    gateway 172.31.64.1
    dns-nameservers 1.1.1.1 8.8.8.8

hosts

sudo nano /etc/hosts

172.31.71.121 k8s-cp-01
172.31.71.131 k8s-node-01

Disable SWAP

sudo swapoff -a
sudo sed -i '/ swap / s/^/#/' /etc/fstab

Install Docker / Containerd

sudo apt install -y containerd

sudo mkdir -p /etc/containerd
containerd config default | sudo tee /etc/containerd/config.toml

sudo nano /etc/containerd/config.toml

# Find and change
[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
SystemdCgroup = true

# Restart containerd
sudo systemctl restart containerd
sudo systemctl enable containerd

Install Kubernetes (kubeadm, kubelet, kubectl)

sudo mkdir -p /etc/apt/keyrings

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

Initialization of the Control Plane

k8s-cp-01

sudo kubeadm init --apiserver-advertise-address=172.31.71.121 --pod-network-cidr=10.244.0.0/16

If not working

sudo modprobe br_netfilter

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

sudo sysctl --system

#* Applying /etc/sysctl.d/k8s.conf ...
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-ip6tables = 1

# check both return 1
cat /proc/sys/net/bridge/bridge-nf-call-iptables
cat /proc/sys/net/ipv4/ip_forward

sudo kubeadm init --apiserver-advertise-address=172.31.71.121 --pod-network-cidr=10.244.0.0/16

Setup kubectl

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

Instalace síťového pluginu (CNI) – Calico

kubectl apply -f https://raw.githubusercontent.com/projectcalico/calico/v3.27.0/manifests/calico.yaml

# after 1-2min
kubectl get pods -A
kubectl get nodes
# status Ready

k8s-node-01

sudo modprobe br_netfilter

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

sudo sysctl --system

kubeadm join 172.31.71.121:6443 --token htnqgq.ymybrkv9fw7dt2jk \
        --discovery-token-ca-cert-hash sha256:0483fbcc6b68518a0935aa092eade2b24763b8aad73544df66132f749307d146

kubectl get nodes

Notes

# on CP
# get token
sudo kubeadm token create --print-join-command
# result run on node server

# on Node
# reset node server
sudo kubeadm reset -f
rm -rf /etc/kubernetes
sudo kubeadm join 172.31.71.121:6443 --token ...

# on CP
kubectl get nodes

hosts