This is an example of a music API server with DB connection (Node.js, Express, Sequelize).
$ npm install
# development
$ npm run dev
# build
$ npm run build
# production mode
$ npm run start
NODE_ENV
DB_USERNAME_DEV
DB_PASSWORD_DEV
DB_NAME_DEV
DB_HOST_DEV
DB_USERNAME_TEST
DB_PASSWORD_TEST
DB_NAME_TEST
DB_HOST_TEST
DB_USERNAME_PROD
DB_PASSWORD_PROD
DB_NAME_PROD
DB_HOST_PROD