goenvdiff

Git-aware .env drift detector for platform engineers, SREs, and developers.

goenvdiff identifies differences in .env configuration files across Git branches or commits. It compares key-value pairs and shows what’s added, removed, or changed — useful during code reviews, DevOps audits, or deployment validations.

Features

• Git-aware comparison of .env files across branches or commits
• Shows added, removed, and modified keys
• Color-coded terminal output
• JSON output support via --json for automation
• Simple and extensible CLI using Cobra

Installation & Environment Setup

Requirements

• Go 1.20 or higher
• Git CLI installed
• VS Code or any text editor

Setup Locally

git clone https://github.com/yourusername/goenvdiff.git
cd goenvdiff
go mod tidy
go build -o goenvdiff

Optional: Install Globally

go install github.com/yourusername/goenvdiff@latest

Usage

goenvdiff --from main --to feature/login --path .env

Sample Output

+ API_KEY added (abc123)
- DEBUG removed (was true)
~ PORT changed from 8080 to 9090

JSON Mode

goenvdiff --from main --to feature/login --path .env --json

[
  { "Key": "API_KEY", "OldValue": "", "NewValue": "abc123", "Type": 0 },
  { "Key": "DEBUG", "OldValue": "true", "NewValue": "", "Type": 1 },
  { "Key": "PORT", "OldValue": "8080", "NewValue": "9090", "Type": 2 }
]

Project Structure

.
├── main.go               # Entry point; wires up CLI
├── cmd/
│   └── root.go           # Cobra CLI setup and flag handling
├── internal/
│   ├── diff.go           # Core diffing logic
│   ├── git.go            # Reads `.env` from Git refs (branches/commits)
│   └── env.go            # Placeholder for env validation or merging
├── go.mod                # Go module metadata
├── .gitignore
├── README.md             # Project documentation
└── testdata/             # (Optional) Test fixtures for `.env` files

Architecture Overview

+------------+         +------------------+         +---------------+
| Git Commit |  --->   | Read .env file   |  --->   | Parse KeyVals |
+------------+         +------------------+         +---------------+
       |                                                  |
       |                                                  v
       |                                      +--------------------------+
       +---> another Git ref --->            | Diff Key-Value Pairs      |
                                             |  - Added / Removed / Mod  |
                                             +--------------------------+
                                                             |
                                                             v
                                      +------------------------------------+
                                      | Print Output or Export as JSON     |
                                      +------------------------------------+

Running Tests

go test ./internal/...

Steps to Reproduce

1. Create .env files on two Git branches:

echo "PORT=8080\nDEBUG=true" > .env
git checkout -b main
git add .env && git commit -m "main env"

git checkout -b feature/login
echo "PORT=9090\nAPI_KEY=xyz" > .env
git commit -am "feature env"

2. Run the tool:

goenvdiff --from main --to feature/login --path .env

Roadmap

• Support multi-file diffs (.env.production, .env.development)
• HTML/Markdown export
• Git pre-commit integration
• Homebrew install formula

License

MIT — feel free to use, extend, and contribute.

Contributing

Feel free to fork, file issues, or submit PRs. Run go fmt ./... before committing.