This setup includes a Node.js server using NestJS, a PostgreSQL database, and utilizes Docker for containerization.

Docker Compose File (docker-compose.yml):

version: '3.8'
services:
  nestjs-app:
    build:
      context: .
      dockerfile: Dockerfile
    ports:
      - '3000:3000'
    depends_on:
      - postgres
    environment:
      DATABASE_HOST: postgres
      DATABASE_PORT: 5432
      DATABASE_USERNAME: postgres
      DATABASE_PASSWORD: mysecretpassword
      DATABASE_NAME: mydb
    networks:
      - my-network

  postgres:
    image: postgres:13
    environment:
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: mysecretpassword
      POSTGRES_DB: mydb
    volumes:
      - postgres-data:/var/lib/postgresql/data
    networks:
      - my-network

networks:
  my-network:
    driver: bridge

volumes:
  postgres-data:

Dockerfile:

# Use the official Node.js image as the base image
FROM node:14-alpine

# Set the working directory inside the container
WORKDIR /app

# Copy package.json and package-lock.json to the container
COPY package*.json ./

# Install the dependencies
RUN npm install

# Copy the rest of the application code to the container
COPY . .

# Expose the port on which the NestJS app will run
EXPOSE 3000

# Start the NestJS application
CMD [ "npm", "start" ]

Explanation:

• The Docker Compose file defines two services: nestjs-app and postgres.
• The nestjs-app service is built using the Dockerfile in the current directory. It exposes port 3000 and depends on the postgres service. Environment variables are provided to connect to the PostgreSQL database.
• The postgres service uses the official PostgreSQL image, sets environment variables for the database configuration, and creates a named volume to persist the database data.
• Both services are connected to a custom bridge network named my-network.
• The Dockerfile uses the official Node.js 14 Alpine image as the base image.
• It sets the working directory, copies package.json and package-lock.json, and installs dependencies.
• The application code is copied to the container, and port 3000 is exposed.
• The CMD instruction starts the NestJS application when the container is run.

This setup allows you to easily containerize and deploy your NestJS application along with a PostgreSQL database using Docker Compose. Remember to adjust environment variables, database credentials, and other configuration parameters as needed for your specific project.