Docker Compose for Local Development

Docker Compose transforms local development by making your environment reproducible and shareable. New team members run docker compose up and have a working development environment in minutes instead of spending a day installing dependencies.

The Basic Stack

A typical web application development stack includes: your application (with volume mounts for hot reload), PostgreSQL (with a named volume for data persistence), Redis (for caching and queues), and Mailhog or Mailpit (for capturing outgoing emails). Define each service in docker-compose.yml with its image, ports, volumes, and environment variables.

Hot Reload with Volume Mounts

Mount your source code directory into the application container so file changes trigger hot reload. For Node.js apps, mount the entire project except node_modules — use a named volume for node_modules to avoid overwriting the container dependencies with your host OS modules. This gives you the fast feedback loop of local development with the consistency of containerized dependencies.

Database Initialization

Use Docker Compose init scripts to set up your database on first run. For PostgreSQL, mount a .sql file to /docker-entrypoint-initdb.d/ to create extensions, roles, and initial schema. Pair this with Prisma migrations that run on application startup for a fully automated database setup.

Environment Configuration

Use a .env file for configuration and reference variables in docker-compose.yml with the ${VARIABLE} syntax. Keep a .env.example in version control with placeholder values. Docker Compose automatically reads .env files, so developers only need to copy the example and fill in their values.

Development vs Production

Maintain separate compose files: docker-compose.yml for the base configuration and docker-compose.override.yml for development-specific settings (volume mounts, debug ports, development images). Docker Compose merges these automatically. For production, use docker-compose.prod.yml with optimized images, resource limits, and health checks.