Docker Compose Local Development

You are working with custom Docker Compose local development environments.

Environment Awareness

When working on a project with Docker:

1. First check for docker-compose.yml or compose.yml in project root
2. Look for .env or .env.local for environment variables
3. Check for Makefile or shell scripts that wrap Docker commands
4. Note any docker/ directory with custom Dockerfiles

Common Patterns

Starting the Environment

# Standard
docker compose up -d

# With build
docker compose up -d --build

# Specific services
docker compose up -d web db

Executing Commands

# Run command in running container
docker compose exec <service> <command>

# Examples
docker compose exec php composer install
docker compose exec php drush cr
docker compose exec php bash

# Run in new container (useful if container isn't running)
docker compose run --rm php composer install

Logs and Debugging

docker compose logs -f           # Follow all logs
docker compose logs -f php       # Follow specific service
docker compose ps                # Show running containers
docker compose top               # Show processes

Cleanup

docker compose down              # Stop and remove containers
docker compose down -v           # Also remove volumes (DATABASE LOSS!)
docker compose rm -f             # Remove stopped containers

Project-Specific Notes

Drupal in Docker

Common Container Names

Check your project's compose file, but common patterns:

• PHP/Web: php, web, app, drupal, php-fpm
• Database: db, mysql, mariadb, postgres
• Cache: redis, memcached

Running Drush

# Find the right container name first
docker compose ps

# Then run drush
docker compose exec <php-container> drush <command>
docker compose exec <php-container> ./vendor/bin/drush <command>

Database Access

# MySQL/MariaDB
docker compose exec db mysql -u root -p

# Import database
docker compose exec -T db mysql -u root -p<password> <dbname> < dump.sql

# Export database
docker compose exec db mysqldump -u root -p<password> <dbname> > dump.sql

Troubleshooting

Port Conflicts

# Find what's using a port
sudo lsof -i :80
sudo lsof -i :3306

# Or check all docker ports
docker ps --format "table {{.Names}}\t{{.Ports}}"

Container Won't Start

# Check logs
docker compose logs <service>

# Rebuild from scratch
docker compose down
docker compose build --no-cache
docker compose up -d

Permission Issues

# Check user in container
docker compose exec <service> id

# Fix permissions (if needed)
docker compose exec <service> chown -R www-data:www-data /var/www/html

Network Issues

# List networks
docker network ls

# Inspect network
docker network inspect <project>_default

# Containers can reach each other by service name
# e.g., from php container: mysql -h db -u root

Environment Variables

.env File

Docker Compose automatically loads .env from project root:

COMPOSE_PROJECT_NAME=myproject
PHP_VERSION=8.2
MYSQL_ROOT_PASSWORD=root

In docker-compose.yml

services:
  php:
    environment:
      - PHP_MEMORY_LIMIT=512M
    env_file:
      - .env.local

Tips

1. Use Makefile - Wrap complex commands for team consistency
2. Document container names - Each project may differ
3. Check ports before starting - Avoid conflicts with other projects
4. Use docker compose profiles - For optional services
5. Volume for vendor - Speed up composer in containers

Adding Project Patterns

As you work with different projects, add their patterns above in the "Project-Specific Notes" section. Include:

• How to start/stop
• Container names for PHP, DB
• Any custom scripts or make targets
• Known conflicts with other projects