environment_setup.md

Environment Variable Setup Guide

This guide explains how environment variables are loaded in different deployment scenarios.

Overview

The environment variables are injected by the container runtime or shell environment. This approach ensures compatibility with:

• ✅ Docker Compose - via env_file directive
• ✅ Kubernetes - via ConfigMaps and Secrets
• ✅ Local Development - via shell export or IDE configuration

Docker Compose (Recommended for Development)

How It Works

The docker-compose.yml file uses the env_file directive to load environment variables from ./api/.env:

api:
  env_file:
    - ./api/.env
  environment:
    - DATABASE_URL=postgresql://...

Important: The env_file directive reads the .env file from the host and injects variables as environment variables into the container. It does not copy the file into the container.

Setup

1. Create or update api/.env with your configuration:

   cp api/.env.example.full api/.env
   # Edit api/.env with your settings

2. Start services:

   docker-compose up --build -d

3. Verify environment variables are loaded:

   docker-compose exec api env | grep DATABASE_URL

Troubleshooting

Environment Variables Not Loading in Docker Compose

1. Check that env_file is specified in docker-compose.yml
2. Verify the .env file exists at ./api/.env
3. Restart services: docker-compose restart
4. Check logs: docker-compose logs api

Best Practices

1. Never commit .env files - they contain secrets
2. Use .env.example to document required variables
3. In K8s, use Secrets for sensitive data
4. In Docker Compose, use env_file for convenience
5. For CI/CD, inject env vars via pipeline configuration