Docker Compose Quickstart

Content

# Docker Compose quickstart

## Minimal web + db

```yaml
services:
  web:
    image: nginx:alpine
    ports:
      - "8080:80"
    depends_on:
      - db
  db:
    image: postgres:16-alpine
    environment:
      POSTGRES_PASSWORD: secret
    volumes:
      - pgdata:/var/lib/postgresql/data
volumes:
  pgdata:
```

## Common commands
docker compose up -d
docker compose ps
docker compose logs -f web
docker compose exec db psql -U postgres
docker compose down          # stop
docker compose down -v       # stop + delete volumes

## Tips
- Put secrets in a `.env` file next to compose.yaml (Compose loads it automatically).
- Prefer named volumes over bind mounts for databases.
- Pin image tags (`postgres:16-alpine`) instead of `latest` in production.
- Healthchecks + `depends_on: condition: service_healthy` avoid racey startups.