Kubernetes Cluster Management Scripts

A comprehensive set of scripts for managing Kubernetes clusters on Ubuntu systems, including installation, configuration, and cleanup operations.

Table of Contents

• Overview
• Prerequisites
• Installation Guide
• Cleanup Guide
• Post-Installation Configuration
• Troubleshooting
• Support

Overview

This repository provides two main scripts:

• setup-k8s.sh: For installing and configuring Kubernetes nodes
• cleanup-k8s.sh: For safely removing Kubernetes components from nodes

Blog and additional information: https://www.munenick.me/blog/k8s-setup-script

Prerequisites

System Requirements

• Ubuntu operating system (tested on Ubuntu 22.04 LTS)
• 2 CPUs or more
• 2GB of RAM per machine
• Full network connectivity between cluster machines

Access Requirements

• Root privileges or sudo access
• Internet connectivity
• Open required ports for Kubernetes communication

Installation Guide

Quick Start

Download and run the installation script:

curl -fsSL https://raw.github.com/MuNeNICK/setup-k8s/main/hack/setup-k8s.sh | sudo bash -s -- [options]

Manual download and inspection:

curl -fsSL https://raw.github.com/MuNeNICK/setup-k8s/main/hack/setup-k8s.sh -o setup-k8s.sh
less setup-k8s.sh
chmod +x setup-k8s.sh

Master Node Installation

Basic setup:

curl -fsSL https://raw.github.com/MuNeNICK/setup-k8s/main/hack/setup-k8s.sh | sudo bash -s -- --node-type master

Advanced setup:

curl -fsSL https://raw.github.com/MuNeNICK/setup-k8s/main/hack/setup-k8s.sh | sudo bash -s -- \
  --node-type master \
  --kubernetes-version 1.29 \
  --pod-network-cidr 192.168.0.0/16 \
  --apiserver-advertise-address 192.168.1.10 \
  --service-cidr 10.96.0.0/12

Worker Node Installation

Obtain join information from master node:

# Run on master node
kubeadm token create --print-join-command

Join worker node:

curl -fsSL https://raw.github.com/MuNeNICK/setup-k8s/main/hack/setup-k8s.sh | sudo bash -s -- \
  --node-type worker \
  --join-token <token> \
  --join-address <address> \
  --discovery-token-hash <hash>

Installation Options Reference

Option	Description	Example
--node-type	Type of node (master/worker)	--node-type master
--kubernetes-version	Kubernetes version	--kubernetes-version 1.29
--pod-network-cidr	Pod network CIDR	--pod-network-cidr 192.168.0.0/16
--apiserver-advertise-address	API server address	--apiserver-advertise-address 192.168.1.10
--control-plane-endpoint	Control plane endpoint	--control-plane-endpoint cluster.example.com
--service-cidr	Service CIDR	--service-cidr 10.96.0.0/12
--join-token	Worker join token	--join-token abcdef.1234567890abcdef
--join-address	Master address	--join-address 192.168.1.10:6443
--discovery-token-hash	Discovery token hash	--discovery-token-hash sha256:abc...

Cleanup Guide

Quick Start

Execute the cleanup script:

curl -fsSL https://raw.github.com/MuNeNICK/setup-k8s/main/hack/cleanup-k8s.sh | sudo bash -s -- [options]

Worker Node Cleanup

1. Drain the node (run on master):

kubectl drain <worker-node-name> --ignore-daemonsets
kubectl delete node <worker-node-name>

2. Run cleanup on worker:

curl -fsSL https://raw.github.com/MuNeNICK/setup-k8s/main/hack/cleanup-k8s.sh | sudo bash -s -- --node-type worker

Master Node Cleanup

Warning: This will destroy your entire cluster.

1. Ensure all worker nodes are removed first
2. Run cleanup:

curl -fsSL https://raw.github.com/MuNeNICK/setup-k8s/main/hack/cleanup-k8s.sh | sudo bash -s -- --node-type master

Cleanup Options Reference

Option	Description	Example
--node-type	Type of node (master/worker)	--node-type master
--force	Skip confirmation prompts	--force
--preserve-cni	Keep CNI configurations	--preserve-cni
--help	Show help message	--help

Post-Installation Configuration

CNI Setup

Install a Container Network Interface (CNI) plugin:

# Example: Installing Calico
kubectl apply -f https://docs.projectcalico.org/manifests/calico.yaml

Single-Node Cluster Configuration

Remove control-plane taint for single-node clusters:

kubectl taint nodes --all node-role.kubernetes.io/control-plane-

Verification Steps

Check cluster status:

kubectl get nodes
kubectl get pods --all-namespaces

Troubleshooting

Installation Issues

• Check kubelet logs:

journalctl -xeu kubelet

• Verify system requirements
• Confirm network connectivity

Worker Node Join Issues

• Verify network connectivity
• Check token expiration (24-hour default)
• Confirm firewall settings

Cleanup Issues

• Ensure proper node drainage
• Verify permissions
• Check system logs:

journalctl -xe

Support

• Issues and feature requests: Open an issue in the repository
• Additional assistance: Contact the maintainer
• Documentation updates: Submit a pull request