How to Set Up PostgreSQL with NestJS and Docker for Fast Local Development: A Quick Guide

This article outlines the process of setting up a local development environment using Docker for NestJS applications with PostgreSQL, without the need for a production database provider.

The following files are required for the setup:

Dockerfile for the NestJS application docker-compose.yml to configure Node.js and PostgreSQL .env file for environment variables Sample NestJS configuration and scripts

docker-compose.yml: Node and PostgreSQL Integration

services: db: image: postgres:13 restart: always env_file:

ports:

volumes:

• .env
• "5432:5432"
• db-data:/var/lib/postgresql/data

api: build: context: . dockerfile: Dockerfile ports:

depends_on:

env_file:

command: sh -c "npm run migration:run && npm run start:dev"

• "3000:3000"
• db
• .env

volumes: db-data:

Note: Using the volumes key allows the database to retain data across reboots.

Create a .env file at the root of your project with the following content:

POSTGRES_USER=postgres POSTGRES_PASSWORD=changeme POSTGRES_DB=app_db POSTGRES_HOST=db POSTGRES_PORT=5432 PORT=3000

Important: Ensure .env is included in .gitignore to protect sensitive information.

Package.json Scripts for Container Management

Add these scripts to your package.json for easier container access:

"scripts": { "db": "docker exec -it $(docker-compose ps -q db) bash", "api": "docker exec -it $(docker-compose ps -q api) bash" }

Use npm run db for the database container shell and npm run api for the application container.

NestJS: Database Connection Configuration

In your main startup file (e.g., main.ts ):

async function bootstrap() { const app = await NestFactory.create(AppModule); await app.listen(process.env.PORT); } bootstrap();

Database Configuration:

A typical configuration file for TypeORM:

const config = { type: "postgres", host: process.env.POSTGRES_HOST, port: parseInt(process.env.POSTGRES_PORT, 10), username: process.env.POSTGRES_USER, password: process.env.POSTGRES_PASSWORD, database: process.env.POSTGRES_DB, entities: [__dirname + "/**/*.entity{.ts,.js}"], synchronize: false, migrations: [__dirname + "/migrations/**/*{.ts,.js}"], autoLoadEntities: true, };

Start all services: docker-compose up --build (initial) or docker-compose up View logs: docker-compose logs -f api Stop and remove containers: docker-compose down Access the database shell: npm run db Access the application container: npm run api

Based on reporting by hackernoon.com.