🔧 Ansible Multi-Node Lab

Automating infrastructure configuration across multiple CentOS servers using Ansible — built hands-on on Apple M3 silicon using UTM virtualization.

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🏗️ Lab Architecture

┌─────────────────────────────────────────────────────┐
│                   HOME LAB                          │
│                                                     │
│   ┌─────────────────────────┐                       │
│   │   AnsibleController     │                       │
│   │   192.168.189.106       │                       │
│   │   CentOS | SSH Keys     │                       │
│   └────────────┬────────────┘                       │
│                │                                    │
│       SSH Key Authentication                        │
│                │                                    │
│      ┌─────────┴──────────┐                         │
│      │                    │                         │
│  ┌───▼──────────┐  ┌──────▼────────┐                │
│  │   Target1    │  │   Target2     │                │
│  │ 192.168.189  │  │ 192.168.189   │                │
│  │    .205      │  │    .121       │                │
│  │   CentOS     │  │   CentOS      │                │
│  └──────────────┘  └───────────────┘                │
│                                                     │
│   Virtualization: UTM on Apple M3                   │
│   SSH Client: Termius                               │
└─────────────────────────────────────────────────────┘

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✅ What This Lab Does

Task	Status
SSH key authentication between controller and nodes	✅ Done
Ansible ping across all nodes	✅ Done
Automated package updates across fleet	✅ Done
Automated software installation on all nodes	✅ Done

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📁 Repository Structure

ansible-lab/
├── inventory.txt        # Host definitions and connection config
├── demo-playbook.yml    # Main playbook — update and install
├── ansible.cfg          # Ansible configuration
└── README.md            # This file

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🔐 Authentication Setup

This lab uses SSH key-based authentication — the production standard for Ansible deployments.

# Generate SSH key on controller
ssh-keygen -t rsa

# Copy public key to each target node
ssh-copy-id senopaul@192.168.189.205
ssh-copy-id senopaul@192.168.189.121

No passwords stored. No password prompts. Secure and automated.

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📋 Inventory Configuration

Target1 ansible_host=192.168.189.205 ansible_user=senopaul
Target2 ansible_host=192.168.189.121 ansible_user=senopaul

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📜 Playbook — Update & Install

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- name: Update and install VLC on servers
  hosts: all
  become: yes
  tasks:
    - name: Update all packages on hosts
      yum:
        name: "*"
        state: latest
      ignore_errors: yes

    - name: Install VLC player
      yum:
        name: vlc
        state: present
      ignore_errors: yes

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🚀 Running the Lab

Test connectivity across all nodes:

ansible all -m ping -i inventory.txt

Expected output:

Target1 | SUCCESS => {"ping": "pong"}
Target2 | SUCCESS => {"ping": "pong"}

Run the full playbook:

ansible-playbook demo-playbook.yml -i inventory.txt

Expected output:

TASK [Update all packages on hosts]
changed: [Target1]
changed: [Target2]

TASK [Install VLC player]
changed: [Target1]
changed: [Target2]

Target1 : ok=3  changed=2  failed=0
Target2 : ok=3  changed=2  failed=0

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🛠️ Tech Stack

Tool	Purpose
Ansible	Configuration management and automation
CentOS	Operating system on all nodes
UTM	Virtualization on Apple M3 silicon
Termius	SSH client for terminal access
Git	Version control

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🌍 About

Built by Paul Ssenoga — Software Engineer transitioning into DevOps.

This lab was built hands-on after a 10-hour workday. Every error is documented. Every fix earned.

Part of a broader DevOps journey covering:

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