Docker Compose allows spinning up containers for databases without installing the databases locally. This post covers the setup for Postgres and Redis images.

Prerequisites

• Docker Compose installed

Configuration

The following configuration spins up Postgres and Redis containers with UI tools (Pgweb and Redis Commander).

Connection strings for Postgres and Redis are redis://localhost:6379 and postgres://username:password@localhost:5435/database-name.

Pgweb and Redis Commander are available at http://localhost:8085 and http://localhost:8081 links.

# docker-compose.yml
version: '3.8'
services:
  postgres:
    image: postgres:alpine
    environment:
      POSTGRES_DB: database-name
      POSTGRES_PASSWORD: password
      POSTGRES_USER: username
    ports:
      - 5435:5432
    restart: on-failure:3
  pgweb:
    image: sosedoff/pgweb
    depends_on:
      - postgres
    environment:
      DATABASE_URL: postgres://username:password@postgres:5432/database-name?sslmode=disable
    ports:
      - 8085:8081
    restart: on-failure:3
  redis:
    image: redis:latest
    command: redis-server
    volumes:
      - redis:/var/lib/redis
      - redis-config:/usr/local/etc/redis/redis.conf
    ports:
      - 6379:6379
    networks:
      - redis-network
  redis-commander:
    image: rediscommander/redis-commander:latest
    environment:
      - REDIS_HOSTS=local:redis:6379
      - HTTP_USER=root
      - HTTP_PASSWORD=qwerty
    ports:
      - 8081:8081
    networks:
      - redis-network
    depends_on:
      - redis
volumes:
  redis:
  redis-config:
networks:
  redis-network:
    driver: bridge

Run the following command to spin up the containers.

docker-compose up

A rate limiter is a standard protection technique against brute force and DDoS attacks. NestJS provides a module for it, and the default storage is in-memory. Custom storage, Redis in this case, should be injected inside ThrottlerModule configuration.

Configuration

The configuration should contain

• TTL (time to live) in seconds
• maximum number of requests within TTL
• Redis URL

// app.module.ts
import { APP_GUARD } from '@nestjs/core';
import { ThrottlerGuard, ThrottlerModule } from '@nestjs/throttler';
import { ThrottlerStorageRedisService } from 'nestjs-throttler-storage-redis';
// ...
@Module({
  imports: [
    ThrottlerModule.forRootAsync({
      inject: [CustomConfigService],
      useFactory: (configService: CustomConfigService) => ({
        ttl: configService.THROTTLER_TTL_SECONDS,
        limit: configService.THROTTLER_LIMIT,
        storage: new ThrottlerStorageRedisService(configService.REDIS_URL),
      }),
    }),
    // ...
  ],
})
export class AppModule {}

API endpoints setup

Binding the throttler guard can be done in multiple ways.

• guard is bound globally for every API endpoint.

// app.module
import { ThrottlerGuard } from '@nestjs/throttler';
// ...
@Module({
  // ...
  providers: [{
    provide: APP_GUARD,
    useClass: ThrottlerGuard,
  }],
})
export class AppModule {}

• global guard is overridden for the specific API endpoint with the Throttle decorator.

import { Throttle } from '@nestjs/throttler';
// ...
@Controller('users')
export class UsersController {
  @Throttle(USERS_THROTTLER_LIMIT, USERS_THROTTLER_TTL_SECONDS)
  @Get()
  async getUsers() {}
}

• global guard is skipped for the specific API endpoint with the SkipThrottle decorator.

import { SkipThrottle } from '@nestjs/throttler';
// ...
@Controller('posts')
export class PostsController {
  @SkipThrottle()
  @Get()
  async getPosts() {}
}

End-to-end tests should use a real database connection, and provisioning container service for the Postgres database can be automated using Github actions. The environment variable for the connection string for the newly created database can be set in the step for running e2e tests. The same goes for the Redis instance.

# ...
jobs:
  build:
    # Container must run in Linux-based operating systems
    runs-on: ubuntu-latest
    # Image from Docker hub
    container: node:18.12.1-alpine3.15
    # ...
    strategy:
      matrix:
        # ...
        database-name:
          - e2e-testing-db
        database-user:
          - username
        database-password:
          - password
        database-host:
          - postgres
        database-port:
          - 5432
        redis-host:
          - redis
        redis-port:
          - 6379
    services:
      postgres:
        image: postgres:latest
        env:
          POSTGRES_DB: ${{ matrix.database-name }}
          POSTGRES_USER: ${{ matrix.database-user }}
          POSTGRES_PASSWORD: ${{ matrix.database-password }}
        ports:
          - ${{ matrix.database-port }}:${{ matrix.database-port }}
        # Set health checks to wait until postgres has started
        options: --health-cmd pg_isready
          --health-interval 10s
          --health-timeout 5s
          --health-retries 5
      redis:
        image: redis
        # Set health checks to wait until redis has started
        options: >-
          --health-cmd "redis-cli ping"
          --health-interval 10s
          --health-timeout 5s
          --health-retries 5
    steps:
      # ...
      - run: npm run test:e2e
        env:
          DATABASE_URL: postgres://${{ matrix.database-user }}:${{ matrix.database-password }}@${{ matrix.database-host }}:${{ matrix.database-port }}/${{ matrix.database-name }}
          REDIS_URL: redis://${{ matrix.redis-host }}:${{ matrix.redis-port }}
      # ...

Further learning

• GitHub actions 101