What Happens Behind the .gitignore: How Git Handles Ignored Files

What Happens Behind the .gitignore How Git Handles Ignored Files

Introduction

Ever wondered how Git treats ignored files like dist/? Using a Python project as an example, we’ll explore what happens in scenarios like CI/CD workflows, cloning, and pulling repositories.

Python Project Example

Typical Structure

my-python-project/
├── src/
│   └── my_package/
│       └── __init__.py
├── tests/
│   └── test_my_package.py
├── dist/
│   ├── my_package-1.0.0-py3-none-any.whl
│   └── my_package-1.0.0.tar.gz
├── .gitignore
├── setup.py
├── README.md
└── requirements.txt

Ignoring dist/ in .gitignore

dist/

The dist/ directory often contains build artifacts (.whl, .tar.gz) generated during packaging. Excluding these from version control helps maintain a clean repository.

Why Ignore dist/?

1. Repository Size Management

🗂️ Without Ignoring dist/:

• Every build adds artifacts to your repository.
• Repository size inflates, slowing down cloning.

📉 With Ignoring dist/:

• Only source code is tracked.
• Repository remains lean and efficient.

2. Avoiding Conflicts

⚠️ Without Ignoring dist/:

• Changes to built files may cause unnecessary merge conflicts.
• Developers might push stale or corrupted artifacts.

✅ With Ignoring dist/:

• Artifacts are generated fresh during CI/CD or locally on-demand.
• Ensures consistency across environments.

3. CI/CD Efficiency

🚧 Without Ignoring dist/:

• CI/CD workflows might use outdated artifacts already pushed.
• Breakages may occur due to stale files.

🚀 With Ignoring dist/:

• CI/CD builds artifacts dynamically, ensuring freshness.
• Reduces errors stemming from stale files.

Possible Scenarios with Ignored Files

1. Pushing Changes

• Ignored files (e.g., dist/) are never pushed.
• Even if locally present, Git ensures these files are excluded from commits.

2. Cloning a Repository

• If dist/ doesn’t exist: The directory isn’t recreated during the clone.
• If CI/CD creates dist/: Cloning excludes it as it’s not tracked in the repository.

3. Pulling Changes

• Ignored files are unaffected during a git pull.
• If the directory exists locally, it remains untouched unless manually modified.

4. CI/CD Workflows

• CI/CD pipelines generate dist/ dynamically as part of the build process.
• Files are temporary and often cleaned up post-build to avoid clutter.

Visual Summary: Ignored File Scenarios

Best Practices for Managing Ignored Files

• Keep .gitignore Updated: Regularly review and adjust patterns to ensure efficiency.
• Avoid Over-Ignoring: Ensure no essential files are inadvertently ignored.
• Use Build Tools for Artifacts: Rely on tools like make, tox, or CI/CD pipelines for dynamic file generation.
• Document Patterns: Include notes in .gitignore to explain why certain files are ignored.