Kubernetes Cluster Setup with Containerd, Calico, Longhorn, and MetalLB

This project demonstrates the offline setup of a multi-node Kubernetes cluster using AlmaLinux servers. The goal was to simulate a real-world, production-like environment as part of a personal DevOps training exercise.

⚠️ Note: All required packages and container images were manually downloaded in advance. If you're following this guide for a production deployment, it's strongly recommended to download the latest versions of each component directly from their official sources.

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🧠 Project Goal

• Learn how Kubernetes works under the hood.
• Practice setting up a fully functional cluster in air-gapped environments.
• Get hands-on experience with real tools like Longhorn, Calico, and MetalLB.

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📊 System Architecture

Below is a simplified diagram of the technologies used:

+------------------+
|  MetalLB         |  <-- LoadBalancer for external traffic
+------------------+
        |
        v
+--------------------------+
| Ingress NGINX Controller|
+--------------------------+
        |
        v
+-------------------------+
| Kubernetes Cluster     |
| - kubeadm, kubectl     |
| - Calico (CNI)         | <-- Network policy and overlay network
| - Longhorn (Storage)   | <-- Distributed persistent volumes
+-------------------------+
        |
        v
+---------------------------+
| Container Runtime:        |
| - containerd              |
+---------------------------+

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🔧 Technologies Used

Tool	Purpose
kubeadm	Initializes the Kubernetes control-plane and joins worker nodes
containerd	Lightweight and production-ready container runtime
Calico	Implements Kubernetes CNI, provides networking and network policy
Longhorn	Distributed block storage for Kubernetes, useful for RWX volumes
MetalLB	LoadBalancer implementation for bare-metal clusters
Ingress NGINX	Handles HTTP routing to services inside the cluster

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🖥️ Nodes Used

This cluster was built using:

• 6 AlmaLinux servers
  • 1 master
  • 5 worker nodes

You can scale the number of worker nodes up or down as needed.

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📁 Repo Contents

This repository includes:

• Shell scripts for offline package installation
• YAML manifests for Kubernetes components
• Preloaded container images
• Configuration files for kubeadm and network/storage tools

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📎 Download This Project

You can clone or download the repository from GitHub using the following link:

git clone https://github.com/enavid/k8s-cluster-from-scratch.git

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📦 Deployment Instructions

For detailed setup steps, please see the INSTALLATION.md guide included in this repository.