Recompose

Recompose is a tiny CLI utility designed to automate the extraction of hardcoded environment variables from Docker Compose files into a structured .env file. It modifies the services block in compose files to use variable interpolation (${VAR_NAME}) and organizes the output into a clean, hierarchical directory.

Features

1. Tree-Aware Refactoring: Parses YAML into an in-memory AST (Abstract Syntax Tree) to preserve original comments, indentation, and formatting.
2. Smart .env Organization:
   1. Global Section: Identifies variables shared across multiple services to reduce redundancy.
   2. Service Sections: Groups unique variables under specific service headers.
3. Dry Run Support: View all proposed changes in a formatted Unicode table before any files are written to disk.
4. Safety First: Always generates files in a dedicated recompose/ directory relative to your source file, ensuring your original configuration remains untouched.
5. Interactive Confirmation: Prompts for final approval before writing, allowing for a safe review of the transformation table.

Installation

Download the recompose binary for your platform from the Releases page and ensure it has execution permissions:

chmod +x recompose

# Optional: move to your bin folder
mv recompose /usr/local/bin/

Usage

Basic Command

./recompose -F docker-compose.yml

Options

Flag	Shorthand	Default	Description
--file	-F	Required	Path to the source docker-compose.yml file.
--generate-compose		TRUE	Creates a refactored compose.yml in the output folder.
--generate-env		TRUE	Creates a formatted .env file in the output folder.
--version	-V		Prints the current version of the binary.
--help	-h		Displays all available commands and flags.

Example: Dry Run

To see the proposed changes without creating any files, set both generation flags to false:

./recompose -F docker-compose.yml -C=false -E=false

Output Structure

When executed, recompose creates a directory named recompose in the same location as your input file:

.
├── docker-compose.yml     <-- Your original file (untouched)
└── recompose/
    ├── .env               <-- New organized environment file
    └── compose.yml        <-- New refactored compose file

Generated .env file example

# GLOBAL VARIABLES
DB_PASSWORD=secret_pass
LOG_LEVEL=info

# SERVICE: WEB
PORT=${PORT}
VIRTUAL_HOST=myapp.local

# SERVICE: WORKER
CONCURRENCY=5

Validations

The tool performs several rigorous checks before processing:

1. Path Resolution: Resolves the absolute path of the input file to ensure the recompose/ folder is placed correctly.
2. Schema Integrity: Validates that the file is a valid YAML document.
3. Compose Compliance: Confirms the services block exists and contains at least one active service definition.
4. Targeted Scanning: Only modifies values within environment blocks, ignoring other configuration keys.

Contributing

Contributions are welcome. If you wish to suggest improvements or report bugs:

1. Fork the repository.
2. Create your feature branch (git checkout -b feature/AmazingFeature).
3. Commit your changes.
4. Push to the branch.
5. Open a Pull Request.

License

Distributed under the MIT License.