---
title: Dokumentasi
tags:
description: .
---

# Setup Kubernetes Cluster Using Kubeadm

---

## Prerequisites

- Minimum two Ubuntu VM (i'm using 22.04 LTS) nodes [One master and one worker node].
- The master node should have a minimum of 2 vCPU and 2GB RAM. For the worker nodes, a minimum of 1vCPU and 2 GB RAM is recommended.
- 192.x.x.x/X network range with static IPs for master and worker nodes. i will be using the 10.x.x.x series as the pod network range that will be used by the Calico network plugin. Make sure the Node IP range and pod IP range don’t overlap. If your IP in 10.x.x.x range, use 192.168.0.0/16 as the POD CIDR.

---

## Setting Static IP (skip for openstack)

network:
version: 2
renderer: NetworkManager
ethernets:
enp0s3:
dhcp4: no
addresses:
[Your IP/24]
routes:
- to: default
via: 192.168.1.1
nameservers:
addresses: [8.8.8.8, 1.1.1.1]

## Following are the steps involved in setting up a kubeadm-based Kubernetes cluster
1. Install container runtime on all nodes- i will be using cri-o.
2. Install Kubeadm, Kubelet, and kubectl on all the nodes.
3. Initiate Kubeadm control plane configuration on the master node.
4. Save the node join command with the token.
5. Install the Calico network plugin (operator).
6. Join the worker node to the master node (control plane) using the join command.
---

# Do this in all nodes
**Login as root**

sudo -i

**Allowing IPtables to see bridged traffic.**

cat <<EOF | sudo tee /etc/modules-load.d/k8s.conf
overlay
br_netfilter
EOF

sudo modprobe overlay
sudo modprobe br_netfilter

# sysctl params required by setup, params persist across reboots
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

# Apply sysctl params without reboot
sudo sysctl --system

**Disable swap**

swapoff -a
(crontab -l 2>/dev/null; echo "@reboot /sbin/swapoff -a") | crontab - || true

**Disable firewall**

ufw disable

### Install CRI-O (Docker engine deprecated)
**Enable cri-o repositories for version 1.28**

OS="xUbuntu_22.04"

VERSION="1.28"

cat <<EOF | sudo tee /etc/apt/sources.list.d/devel:kubic:libcontainers:stable.list
deb https://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/stable/$OS/ /
EOF
cat <<EOF | sudo tee /etc/apt/sources.list.d/devel:kubic:libcontainers:stable:cri-o:$VERSION.list
deb http://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/stable:/cri-o:/$VERSION/$OS/ /
EOF

</br>

**Add the GPG keys for CRI-O to the system’s list of trusted keys.**

curl -L https://download.opensuse.org/repositories/devel:kubic:libcontainers:stable:cri-o:$VERSION/$OS/Release.key | sudo apt-key --keyring /etc/apt/trusted.gpg.d/libcontainers.gpg add -
curl -L https://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/stable/$OS/Release.key | sudo apt-key --keyring /etc/apt/trusted.gpg.d/libcontainers.gpg add -

apt-get update
apt-get install cri-o cri-o-runc cri-tools -y

- CNI plugin configuration (refer to https://github.com/cri-o/cri-o/blob/main/contrib/cni/README.md)

#CNI plugin installation 
git clone https://github.com/containernetworking/plugins
cd plugins
git checkout v1.1.1
./build_linux.sh

#Install the CNI Plugin
sudo mkdir -p /opt/cni/bin
sudo cp bin/* /opt/cni/bin/

#Reload the updated config
systemctl daemon-reload
systemctl enable crio --now
sudo systemctl status cri-o

### Install Kubeadm & Kubelet & Kubectl
**Install dependencies**

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

</br>

**Download the GPG key for the Kubernetes APT repository.**

sudo curl -fsSLo /usr/share/keyrings/kubernetes-archive-keyring.gpg https://dl.k8s.io/apt/doc/apt-key.gpg

</br>**Add the Kubernetes APT repository to your system.**

echo "deb [signed-by=/usr/share/keyrings/kubernetes-archive-keyring.gpg] https://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list
sudo apt-get update -y

</br>**Install kubelet, kubectl and kubeadm (erase the "=1.xx.xx" to install latest version)**

</br>**(Optional) Prevent upgrade**

---
# Do the following in Master node
**Initialize kubeadm**

kubeadm init --apiserver-advertise-address=<ip_VM> --pod-network-cidr=10.85.0.0/16  --ignore-preflight-errors=all --kubernetes-version=vx.xx.x --v=5

**Exit from root and do this command so kubectl works outside root user**

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

**Deploy Calico network plugin**

kubectl create -f https://raw.githubusercontent.com/projectcalico/calico/v3.26.1/manifests/tigera-operator.yaml

curl https://raw.githubusercontent.com/projectcalico/calico/v3.26.1/manifests/custom-resources.yaml -O

kubectl create -f custom-resources.yaml

**Print Join Command**

---

# Do the following in Worker node
- Paste the output from "kubeadm token create --print-join-command" done in master node!

- Do this command in master node


### Written by #INU