feat: dockerized the firewall

[Satvik-Singh192]

📘 Description

This pull request containerizes the Python firewall tool using Docker, fulfilling the requirements of issue #5.
It simplifies deployment and ensures a consistent runtime environment across all systems, handling all dependencies and network permissions automatically.

✅ Key Changes

1. Dockerfile

• Uses the lightweight python:3.10-slim base image.
• Installs gcc and build-essential to compile the netifaces package.
• Installs all runtime dependencies from requirements_docker.txt.
• Removes build tools at the end to keep the image slim.

2. docker-compose.yml

• Configured with:
  • cap_add: [ NET_ADMIN ] → required for managing iptables
  • network_mode: host → needed to inspect/monitor host network interfaces
• Runs the firewall container with correct privileges.

3. entrypoint.sh

• New startup script.
• Automatically checks for firewall_config.json.
  • If missing, runs:

    python main.py --create-config

• Ensures the application always has a valid configuration before launching.

4. .dockerignore

• Excludes:
  • venv/
  • __pycache__/
  • Build artifacts
• Reduces build context size and speeds up Docker builds.

5. requirements_docker.txt

• Contains only runtime dependencies.
• Development tools are separated to keep Docker images lightweight.

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🚀 How to Run

To build and run the firewall:

docker-compose run --rm firewall

🔢 Semver Changes

• Patch (bug fix)
• Minor (new features, no breaking changes)
• Major (breaking changes)

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🔗 Issues

Closes #5

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✅ Checklist

• I have read the Contributing Guidelines.

[Satvik-Singh192]

@utkarshkgithub please review my pull request sir

[Satvik-Singh192]

@utkarshkgithub sir, please review my pull request, thanks