Docker Multi-stage Example (Debian)

This repository demonstrates an optimized multi-stage Docker build based on a generic Linux distribution (debian:bookworm-slim).

The project compiles a small C program in a dedicated builder stage, and runs the final binary in a lightweight runtime stage as a non-root user.

---

📦 Features

• Multi-stage Docker build
• Static C binary compilation
• Non-root runtime user
• Clean Debian base image
• GitHub Actions CI with:
  • Docker build
  • Container run test
  • Output validation

---

🛠 Build the image

docker build -t docker-multistage-example .

---

▶ Run the container

docker run --rm docker-multistage-example

Expected output:

Hello from multi-stage Docker build on Debian!

---

🔁 CI Pipeline (GitHub Actions)

The workflow automatically triggers on:

• any push
• any pull request

It performs:

1. Docker build
2. Program execution inside container
3. Output verification
4. Pass/fail result

You can inspect it under:

.github/workflows/docker-ci.yml

---

📂 Repository Structure

docker-multistage-example/ │

├── Dockerfile

├── src/

│ └── hello.c

├── .github/

│ └── workflows/

│ | └── docker-ci.yml

└── README.md

---

🧩 Why this repo is valuable

• Demonstrates advanced Docker multi-stage techniques
• Shows build optimization and image size reduction
• Highlights secure container practices (non-root user)
• Includes automated CI pipeline
• Great for DevOps / Cloud / Platform Engineering portfolios

---

👤 Author

Gaetano Vespero

DevOps & Automation Engineer | Specialist in CI/CD + AI Workflow Integration