Description

This is an example of creating a backend application using the following set of technologies:

• Nest,
• Typescript,
• Postgresql,
• Typeorm (versions above ^0.3.20)
• Creating Migrations, configuring usage and automatic execution
• Docker(API) - deploying applications to Docker
• Docker(DB) - Deploy DB in Docker

---

Step-by-step instructions for creating project:

---

Project creation and library installation

1. Install nest-cli (If you already have nest-cli installed, skip this step)

npm i -g @nestjs/cli

2. Create a new project using the nest cli

nest new <your-project-name>

If you have already created a folder for the project and are in it:

nest new .

Choose: npm for the package manager (or whichever you prefer)

3. Install TypeOrm

npm install --save @nestjs/typeorm typeorm postgres pg

---

Installation

$ npm install

---

Additional settings

.env

PORT=4003

# -- POSRGRESS
POSTGRES_HOST=db_postgres
POSTGRES_PORT=5432
POSTGRES_USER=postgres
POSTGRES_PASSWORD=postgres
POSTGRES_DATABASE=my_db

PORT - port on which our project will run (used in the src/main.ts)

POSTGRES_HOST - host on which we will access the database

POSTGRES_PORT - database access port

POSTGRES_USER - you can use whatever you want, but don't forget to change in typeorm.config and docker-compose

POSTGRES_PASSWORD - you can use whatever you want, but don't forget to change in typeorm.config and docker-compose

POSTGRES_DATABASE - - you can use whatever you want, but don't forget to change in typeorm.config and docker-compose

They are all used in src/db/typeorm.config.ts end docker-compose.yml

---

typeorm.config.ts

migrationsRun: true,
entities: [__dirname + '/../**/*.entity.{js,ts}'],
migrations: [__dirname + '/migrations/*.{js,ts}'],

migrationsRun: true - We point out to Typeorm the need to check migrations and run them automatically if necessary.

entities: [__dirname + '/../**/*.entity.{js,ts}'] - We specify a Typeorm pattern for finding entities.

migrations: [__dirname + '/migrations/*.{js,ts}'] - We specify a Typeorm path to locate the migration files.

---

app.module.ts

import AppDataSource from 'src/db/typeorm.config';
...
@Module({
...
  imports: [TypeOrmModule.forRootAsync({
    useFactory: () => AppDataSource.options,
  }
  })],
...
}]

Dockers

docker-compose.yml

For API

  nest_api:
    container_name: nest_api
    build:
      context: ./docker/api/dev
      dockerfile: Dockerfile
    user: 'root'
    command: >
      bash -c "npm i
      && npm run build
      && nest start --debug 0.0.0.0:9229 --watch --preserveWatchOutput"
    ports:
      - '4003:4003'
      - '9229:9229'
    volumes:
      - .:/app
    depends_on:
      - db_postgres
    environment:
      - NODE_ENV=development

---

    build:
      context: ./docker/api/dev
      dockerfile: Dockerfile

Dockerfile location and name.

---

    ports:
      - '4003:4003'

Port on which we can access the application.

---

    depends_on:
      - db_postgres

Specify the name of the database container as a dependency.

The same name we use to access the database in typeorm.config.ts by specifying it in .env POSTGRES_HOST=db_postgres.

---

    environment:
      - NODE_ENV=development

Optional parameter, but sometimes without it the project autocompilation does not start after making changes in developer mode.

---

For DB

  db_postgres:
    container_name: db_postgres
    image: postgres:14.6-alpine
    restart: always
    user: root
    environment:
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: postgres
      POSTGRES_DB: my_db
    ports:
      - '5432:5432'
    volumes:
      - ./docker/pgdata:/var/lib/postgresql/data

---

    container_name: db_postgres

The container name we use in depends_on: for the application docker and in .env POSTGRES_HOST=db_postgres

---

    environment:
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: postgres
      POSTGRES_DB: my_db

Database parameters that we also use in typeorm.config.ts and .env.

---

    volumes:
      - ./docker/pgdata:/var/lib/postgresql/data

Specify the directory where the created database will be physically stored.

---

Run API in local docker environment

Be sure that the docker engine and docker compose utility are installed on your machine

The next steps are needed in any system:

• Start api and db using docker-compose up

You can drop ./docker/pgdata folder to delete all data in DB.

You can connect debugger as external one to localhost:9229. Chose Attach to Node.js/Chrome on Webstorm debugger config page and enjoy

Migrations

Add the following commands to package.json

{
  ...
  "scripts": {
    ...
    "typeorm:config": "typeorm-ts-node-commonjs -d ./src/db/typeorm.config.ts",
    "migration:generate": "typeorm-ts-node-commonjs migration:generate -d src/db/typeorm.config.ts",
    "migration:run": "typeorm-ts-node-commonjs migration:run -d src/db/typeorm.config.ts",
    "migration:create": "typeorm-ts-node-commonjs migration:create src/db/migrations/migration",
    "migration:revert": "typeorm-ts-node-commonjs migration:revert -d src/db/typeorm.config.ts"
  }
  ...
}

All subsequent commands should be executed inside the nest_api application container.

To enter to nest_api container, after the containers have been fully started, run the command:

docker-compose exec nest_api bash

---

Use to create new migration:

npm run migration:generate src/db/migrations/<my-migration-name>

Migration would appear in src/db/migrations as the last one

---

Use to roll back the last migration:

npm run migration:revert

---

Use to run all migrations:

npm run migration:run

---

Use to run all migrations:

npm run migration:run

Use to create migrations:

npm run migration:create

Use to run one migration:

npm run migration:run src/db/<migration-file.ts>

---

License

It is MIT licensed.