.env to Docker Compose & .env.example Converter

Transform .env files into Docker Compose configurations and generate sanitized .env.example templates with redacted secrets.

Service Name

Base Docker Image

Port Mapping

Restart Policy

Source .env File

Detected 12 environment variables.

docker-compose.yml

version: '3.8'

services:
  api:
    image: node:20-alpine
    container_name: api_service
    restart: unless-stopped
    ports:
      - "3000:3000"
    env_file:
      - .env
    environment:
      - PORT=${PORT}
      - NODE_ENV=${NODE_ENV}
      - APP_URL=${APP_URL}
      - DB_HOST=${DB_HOST}
      - DB_PORT=${DB_PORT}
      - DB_NAME=${DB_NAME}
      - DB_USER=${DB_USER}
      - DB_PASSWORD=${DB_PASSWORD}
      - REDIS_URL=${REDIS_URL}
      - JWT_SECRET=${JWT_SECRET}
      - STRIPE_SECRET_KEY=${STRIPE_SECRET_KEY}
      - STRIPE_WEBHOOK_SECRET=${STRIPE_WEBHOOK_SECRET}
    volumes:
      - .:/app
      - /app/node_modules
    networks:
      - app-network

networks:
  app-network:
    driver: bridge

.env.example (Redacted)

# Application Server Configuration
PORT=3000
NODE_ENV=your_value_here
APP_URL=http://localhost:3000

# PostgreSQL Database
DB_HOST=http://localhost:3000
DB_PORT=3000
DB_NAME=my_database
DB_USER=my_database
DB_PASSWORD=your_password_here

# Redis Cache
REDIS_URL=http://localhost:3000

# Authentication & Third Party APIs
JWT_SECRET=your_secret_key_here
STRIPE_SECRET_KEY=your_secret_key_here
STRIPE_WEBHOOK_SECRET=your_secret_key_here

Best Practices for Managing Environment Variables in Docker

Proper secret hygiene is fundamental to modern containerized microservices:

Always Add .env to .gitignore: Add .env, .env.local, and .env.production to your root .gitignore file before initial git commits.
Commit .env.example to Source Control: Keep your .env.example updated whenever you add a new third-party integration or configuration flag so teammates know what variables are required.
Use Variable Substitution in Compose: Using ${VARIABLE_NAME} in your docker-compose.yml allows values to be dynamically supplied by host CI/CD pipelines without hardcoding credentials into YAML files.

Recommended DevOps Scenarios

✓
Dockerizing Existing Node, Python, or Go Services
Instantly map dozens of environment variables from your local `.env` into a clean multi-container `docker-compose.yml` service specification.
✓
Generating Safe .env.example Templates for GitHub
Strip real database credentials, Stripe private keys, and JWT secrets to create a sanitized `.env.example` file safe to commit to public git repositories.
✓
Standardizing Team Onboarding Configs
Provide new engineers with documented sample environment variable templates containing placeholder tokens without risking production data breaches.
✓
Port Mapping & Volume Mount Automation
Configure custom base container images (Node, Alpine, Postgres), restart policies, and host-to-container port bindings effortlessly.

Key Converter Capabilities

✓

Dual Output Generation (Compose & Example)

Concurrently generates both a production-ready `docker-compose.yml` file and a sanitized `.env.example` template with one click.

✓

Smart Secret Redaction & Token Replacement

Automatically identifies sensitive keys (password, token, secret, key) and replaces real values with safe dummy placeholders (`your_secret_key_here`).

✓

Customizable Docker Container Parameters

Set custom service names, Docker image tags, container restart policies, and port bindings to match your infrastructure requirements.

✓

Direct One-Click Download & Clipboard Copy

Copy YAML markup or download `docker-compose.yml` and `.env.example` files directly to your project workspace.

Frequently Asked Questions

Why should I generate a .env.example file?

A `.env.example` file serves as a blueprint for your project's configuration without exposing sensitive production secrets. Committing real `.env` files to git repositories is one of the most common causes of API key leaks, database compromises, and cloud billing fraud.

How does Docker Compose handle environment variables?

Docker Compose can load environment variables in two ways: via `env_file: .env` (which injects all variables from an external file into the container runtime) or through the `environment:` dictionary (which explicitly maps specific host or shell variables into the container).

Are my secret environment variables sent to any external server?

No. All string parsing, regex sanitization, and YAML compilation happen 100% locally inside your web browser. Your private API keys and database credentials never leave your machine.

Can I use the output for production Docker deployments?

Yes! The generated `docker-compose.yml` strictly follows the official Compose Specification version 3.8, compatible with Docker Desktop, Docker Swarm, and cloud virtual machines running Ubuntu or Debian.