Infra Docker

Docker Local Development Skill

Docker Compose patterns for local development environments including PostgreSQL and supporting services.

When to Use This Skill

• Setting up local PostgreSQL for development
• Managing development databases
• Adding local services (Redis, etc.)
• Standardizing team development environments

Quick Start

Minimal Setup (PostgreSQL Only)

Create docker-compose.yml in project root:

services:
  postgres:
    image: postgres:16-alpine
    container_name: myapp-postgres
    restart: unless-stopped
    environment:
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: postgres
      POSTGRES_DB: myapp
    ports:
      - "5432:5432"
    volumes:
      - postgres_data:/var/lib/postgresql/data
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U postgres"]
      interval: 5s
      timeout: 5s
      retries: 5

volumes:
  postgres_data:

Commands

# Start services
docker compose up -d

# View logs
docker compose logs -f postgres

# Stop services
docker compose down

# Stop and remove volumes (reset database)
docker compose down -v

# Check status
docker compose ps

Environment Variables

.env.local

# Database
DATABASE_URL=postgres://postgres:postgres@localhost:5432/myapp

docker-compose.yml with .env file

services:
  postgres:
    image: postgres:16-alpine
    environment:
      POSTGRES_USER: ${POSTGRES_USER:-postgres}
      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-postgres}
      POSTGRES_DB: ${POSTGRES_DB:-myapp}
    ports:
      - "${POSTGRES_PORT:-5432}:5432"
    volumes:
      - postgres_data:/var/lib/postgresql/data

volumes:
  postgres_data:

Extended Setup

PostgreSQL + Redis

services:
  postgres:
    image: postgres:16-alpine
    container_name: myapp-postgres
    restart: unless-stopped
    environment:
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: postgres
      POSTGRES_DB: myapp
    ports:
      - "5432:5432"
    volumes:
      - postgres_data:/var/lib/postgresql/data
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U postgres"]
      interval: 5s
      timeout: 5s
      retries: 5

  redis:
    image: redis:7-alpine
    container_name: myapp-redis
    restart: unless-stopped
    ports:
      - "6379:6379"
    volumes:
      - redis_data:/data
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 5s
      timeout: 5s
      retries: 5

volumes:
  postgres_data:
  redis_data:

With pgAdmin (Database GUI)

services:
  postgres:
    image: postgres:16-alpine
    container_name: myapp-postgres
    environment:
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: postgres
      POSTGRES_DB: myapp
    ports:
      - "5432:5432"
    volumes:
      - postgres_data:/var/lib/postgresql/data

  pgadmin:
    image: dpage/pgadmin4:latest
    container_name: myapp-pgadmin
    environment:
      PGADMIN_DEFAULT_EMAIL: admin@local.dev
      PGADMIN_DEFAULT_PASSWORD: admin
      PGADMIN_CONFIG_SERVER_MODE: "False"
    ports:
      - "5050:80"
    volumes:
      - pgadmin_data:/var/lib/pgadmin
    depends_on:
      - postgres

volumes:
  postgres_data:
  pgadmin_data:

Access pgAdmin at http://localhost:5050

With Minio (S3-Compatible Storage)

services:
  minio:
    image: minio/minio:latest
    container_name: myapp-minio
    command: server /data --console-address ":9001"
    environment:
      MINIO_ROOT_USER: minioadmin
      MINIO_ROOT_PASSWORD: minioadmin
    ports:
      - "9000:9000"  # API
      - "9001:9001"  # Console
    volumes:
      - minio_data:/data

volumes:
  minio_data:

Access Minio Console at http://localhost:9001

Database Operations

Connect with psql

# Using Docker
docker compose exec postgres psql -U postgres -d myapp

# Direct connection (if psql installed locally)
psql postgres://postgres:postgres@localhost:5432/myapp

Common psql Commands

-- List databases
\l

-- Connect to database
\c myapp

-- List tables
\dt

-- Describe table
\d user

-- Show table data
SELECT * FROM "user" LIMIT 10;

-- Exit
\q

Backup and Restore

# Backup
docker compose exec postgres pg_dump -U postgres myapp > backup.sql

# Restore
docker compose exec -T postgres psql -U postgres myapp < backup.sql

# Backup specific tables
docker compose exec postgres pg_dump -U postgres -t user -t session myapp > users_backup.sql

Reset Database

# Drop and recreate
docker compose exec postgres psql -U postgres -c "DROP DATABASE IF EXISTS myapp;"
docker compose exec postgres psql -U postgres -c "CREATE DATABASE myapp;"

# Or restart with fresh volume
docker compose down -v
docker compose up -d

Package.json Scripts

Add convenient scripts:

{
  "scripts": {
    "docker:up": "docker compose up -d",
    "docker:down": "docker compose down",
    "docker:reset": "docker compose down -v && docker compose up -d",
    "docker:logs": "docker compose logs -f",
    "docker:psql": "docker compose exec postgres psql -U postgres -d myapp",
    "db:generate": "drizzle-kit generate",
    "db:migrate": "tsx src/lib/db/migrate.ts",
    "db:studio": "drizzle-kit studio",
    "dev": "next dev",
    "dev:full": "docker compose up -d && next dev"
  }
}

Development Workflow

Daily Workflow

# Start services (if not running)
npm run docker:up

# Run migrations (if schema changed)
npm run db:migrate

# Start dev server
npm run dev

After Schema Changes

# Generate migration
npm run db:generate

# Apply migration
npm run db:migrate

# Verify in Drizzle Studio
npm run db:studio

Fresh Start

# Reset everything
npm run docker:reset

# Run migrations
npm run db:migrate

Health Checks

Verify Services Running

# Check container status
docker compose ps

# Expected output:
# NAME              STATUS
# myapp-postgres    Up (healthy)
# myapp-redis       Up (healthy)

Wait for Database

Script to wait for PostgreSQL before running commands:

#!/bin/bash
# wait-for-db.sh

echo "Waiting for PostgreSQL..."
until docker compose exec postgres pg_isready -U postgres > /dev/null 2>&1; do
  sleep 1
done
echo "PostgreSQL is ready!"

Troubleshooting

Port Already in Use

# Find what's using port 5432
lsof -i :5432

# Kill the process or use a different port
# In docker-compose.yml:
ports:
  - "5433:5432"  # Map to different local port

Container Won't Start

# Check logs
docker compose logs postgres

# Common issues:
# - Port conflict: change port mapping
# - Volume permissions: docker compose down -v
# - Image pull failed: docker compose pull

Connection Refused

# Verify container is running
docker compose ps

# Verify port mapping
docker compose port postgres 5432

# Test connection
docker compose exec postgres pg_isready -U postgres

Slow Startup

# Pre-pull images
docker compose pull

# Check disk space
docker system df

# Clean up unused resources
docker system prune

Gitignore

Add to .gitignore:

# Docker volumes (if not using named volumes)
.docker-data/

# Local environment overrides
docker-compose.override.yml

Production Considerations

This setup is for local development only. For production:

• Use managed database services (AWS RDS, Aurora, etc.)
• Never use default passwords
• Configure proper networking and security groups
• Set up backups and monitoring
• See infra-aws skill for production deployment

Quick Reference