DevOps Project

This repository contains the main DevOps project with a coffee delivery service.

Infrastructure

VCL Machines:

• VCL 1: 152.7.178.184 (Routing and DNS)
• VCL 2: 152.7.178.106 (Primary server with auto-deployment)
• VCL 3: 152.7.178.91 (Cold standby server with DB replication)

High Availability Features:

• ✅ Automatic deployment to VCL2 on merge to main branch
• ✅ Database replication from VCL2 to VCL3 every 2 minutes
• ✅ Auto-sync dev branch after PR merge to main
• ✅ Linting and testing in CI/CD pipeline

Quick Start with Docker

Run the coffee project with PostgreSQL database using Docker:

cd coffee_project
docker-compose up -d

This starts:

• Coffee app on http://localhost:3000
• PostgreSQL database on port 5432

Test the app

# Get available coffees
curl http://localhost:3000/coffees

# Place an order
curl -X POST http://localhost:3000/order \
  -H "Content-Type: application/json" \
  -d '{"coffeeId": 1, "quantity": 2}'

Stop containers

docker-compose down

High Availability Setup

Database Replication (VCL2 → VCL3)

Automatic database replication runs every 2 minutes to keep VCL3 in sync with VCL2.

Setup on VCL2:

# Quick setup
cd ~/devops-project
chmod +x scripts/setup-replication.sh
./scripts/setup-replication.sh

# Follow the prompts to complete setup

Detailed Documentation:

• Replication Setup Guide
• Systemd Timer Setup

Monitor Replication:

# View replication logs
tail -f /var/log/coffee-replication/replicate.log

# Check replication status (if using systemd)
systemctl status coffee-replication.timer

Failover to VCL3

If VCL2 fails, activate VCL3:

# On VCL3
cd ~/devops-project/coffee_project
docker-compose up -d

# Verify
curl http://localhost:3000/coffees

Then update DNS/routing on VCL1 to point traffic to VCL3.

Database setup (PostgreSQL)

This project uses PostgreSQL for the coffee_project service. The app reads the connection from the DATABASE_URL environment variable. If DATABASE_URL is not set, the project defaults to:

postgresql://postgres:postgres@localhost:5432/coffee_dev

Quick start (Docker)

1. Start a local Postgres container:

docker run --name coffee-pg -e POSTGRES_PASSWORD=postgres -e POSTGRES_DB=coffee_dev -p 5432:5432 -d postgres:15

2. Install dependencies and run the migration to create tables and seed the coffee catalogue:

cd coffee_project
npm install
npm run migrate

3. Start the service:

npm start
# or run in a detached screen session:
screen -S coffee -dm sh -c 'npm start'

Using an existing / hosted database

If you have a hosted Postgres instance, set DATABASE_URL before running the migrate script or starting the server:

export DATABASE_URL='postgresql://USER:PASSWORD@HOST:PORT/DBNAME'
npm run migrate
npm start

CI (GitHub Actions) notes

If you run tests or migrations in GitHub Actions, start a Postgres service in the job and set DATABASE_URL to point to the service. Example snippet for a job in .github/workflows/*.yml:

services:
	postgres:
		image: postgres:15
		env:
			POSTGRES_DB: coffee_test
			POSTGRES_USER: postgres
			POSTGRES_PASSWORD: postgres
		ports: ['5432:5432']
		options: >-
			--health-cmd pg_isready
			--health-interval 10s
			--health-timeout 5s
			--health-retries 5

env:
	DATABASE_URL: postgres://postgres:postgres@localhost:5432/coffee_test

Cleanup

To stop and remove the local docker container:

docker stop coffee-pg && docker rm coffee-pg

Questions or different DB?

If you'd prefer a different database (MySQL, MongoDB, etc.) I can adapt the code and migration script — tell me which one and I'll implement the change.

Automated Deployment

The project uses GitHub Actions to automatically deploy to VCL 2 when code is merged to main.

How it works

1. When a PR is merged to main, the deployment workflow triggers
2. The workflow (running on the self-hosted runner on VCL 1) SSHs into VCL 2
3. Pulls the latest code from the main branch
4. Stops old Docker containers
5. Rebuilds and starts new containers with the updated code
6. The app becomes accessible at http://152.7.178.106:3000

Prerequisites for deployment

On VCL 2 (152.7.178.106):

• Docker and Docker Compose installed
• Project cloned at ~/devops-project
• SSH access configured for GitHub Actions

GitHub Repository Secrets (required):

• VCL2_SSH_PRIVATE_KEY - SSH private key for accessing VCL 2
• VCL2_SSH_KNOWN_HOSTS - (optional) Host key for VCL 2

Setting up SSH for GitHub Actions

1. Generate a dedicated SSH key pair:

ssh-keygen -t ed25519 -C "github-actions-deploy" -f ~/.ssh/github_actions_deploy_key

2. Copy the public key to VCL 2:

ssh-copy-id -i ~/.ssh/github_actions_deploy_key.pub [email protected]

3. Add the private key to GitHub Secrets:

# Copy the private key
cat ~/.ssh/github_actions_deploy_key

# Go to: Repository Settings → Secrets and variables → Actions
# Create secret: VCL2_SSH_PRIVATE_KEY
# Paste the entire private key content (including BEGIN/END lines)

4. (Optional) Add known hosts:

ssh-keyscan -H 152.7.178.106

# Add as secret: VCL2_SSH_KNOWN_HOSTS

Manual deployment on VCL 2

If you need to deploy manually:

ssh [email protected]
cd ~/devops-project
git pull origin main
cd coffee_project
docker-compose down
docker-compose up -d --build

Accessing the deployed app

Once deployed, the coffee delivery service is accessible at:

• http://152.7.178.106:3000

Test endpoints:

# Get available coffees
curl http://152.7.178.106:3000/coffees

# Place an order
curl -X POST http://152.7.178.106:3000/order \
  -H "Content-Type: application/json" \
  -d '{"coffeeId": 1, "quantity": 2}'

# View all orders
curl http://152.7.178.106:3000/orders