Chirp — ITU MiniTwit

Chirp is a Twitter-like blogging platform built as part of the ITU BSc Software Development & DevDevOps, Software Evolution and Software Maintenance courses .

The app is deployed on DigitalOcean using Docker Swarm and is live at https://itu-minitwit.duckdns.org.

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Features

• Post, view, and delete cheeps (messages up to 160 characters)
• Follow / unfollow other users with a personalised timeline
• OAuth sign-in via GitHub, Google, Facebook, and Microsoft Account
• Simulator-compatible REST API (/register, /msgs, /fllws, /latest)
• Real-time metrics with Prometheus + Grafana dashboards
• Centralised log aggregation with Loki and Grafana Alloy
• Horizontal scaling via Docker Swarm (2 app replicas)

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Tech Stack

Layer	Technology
Web framework	ASP.NET Core 8 (Razor Pages)
Language	C# (.NET 8)
Database	PostgreSQL 16
Cache / session store	Redis 7
ORM	Entity Framework Core 8 (Npgsql)
Containerisation	Docker + Docker Swarm
Monitoring	Prometheus, Grafana, Loki, Grafana Alloy
CI/CD	GitHub Actions
Hosting	DigitalOcean (Docker Swarm)

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Project Structure

ITU-MiniTwit/
├── src/
│   ├── Chirp.Core/           # Domain models and interfaces
│   ├── Chirp.Infrastructure/ # EF Core repositories and services
│   └── Chirp.Web/            # ASP.NET Razor Pages app + REST API
├── test/
│   ├── UnitTests/
│   ├── IntegrationTests/
│   └── End2End/              # Playwright browser tests
├── scripts/
│   ├── provision_itu_minitwit.sh  # Spin up a DigitalOcean droplet
│   ├── bootstrap.sh               # Install Docker on a fresh droplet
│   └── deploy.sh                  # Pull and restart containers
├── monitoring/               # Prometheus, Loki, Grafana, Alloy configs
├── docker-compose.yml        # Local development compose file
├── docker-stack.yml          # Production Swarm stack (app + Redis)
├── docker-stack.monitoring.yml # Production Swarm stack (monitoring)
└── Dockerfile                # Multi-stage build for the web app

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Production Deployment

The production system runs on DigitalOcean as a Docker Swarm cluster.

Architecture

Internet → itu-minitwit.duckdns.org
                │
          Docker Swarm manager
          ├── minitwit stack
          │   ├── itu-minitwit (2 replicas, port 5001)
          │   ├── redis (session store)
          │   └── node-exporter
          └── monitoring stack
              ├── prometheus (port 9090)
              ├── grafana (port 3000)
              ├── loki (port 3100)
              └── alloy (log collector, global mode)

CI/CD Pipeline

All automation lives in .github/workflows/.

Workflow	Trigger	What it does
CI.yml	Push to main, PRs	Build → unit/integration tests → E2E tests → SonarCloud → Trivy image scan
CD.yml	CI passes on main	Build & push Docker image → deploy Swarm stack → deploy monitoring stack
WeeklyRelease.yml	week* tags	Tag-based release automation
WeeklyHostUpdate.yml	Schedule	Automated host OS updates

The CD pipeline:

1. Builds and pushes a Docker image tagged with the git SHA to Docker Hub.
2. SSHs into the swarm manager and writes the production .env (from GitHub secrets).
3. Deploys docker-stack.yml (app + Redis) and docker-stack.monitoring.yml.
4. Performs a health check against https://itu-minitwit.duckdns.org.

Required GitHub secrets: DOCKER_USERNAME, DOCKER_PASSWORD, SSH_HOST_APP2, SSH_USER, SSH_KEY_APP2, DO_CONNECTION_STRING, DO_REDIS_CONNECTION_STRING, SONAR_TOKEN.

CI/CD in action

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Monitoring & logging

Can be found on http://165.245.209.232:3000/.

Service	URL (production)	Purpose
Grafana	:3000	Dashboards for app metrics and logs
Prometheus	:9090	Metrics scraping and storage
Loki	:3100	Log aggregation
Grafana Alloy	—	Ships container logs to Loki

The app exposes a /metrics endpoint (Prometheus format) and a /health endpoint used by the Swarm healthcheck.

Monitoring in action

Logging in action

IAC in action

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License

This project is licensed under the MIT License — see LICENSE.md for details.