@sclable/nestjs-queue NPM

NestJS Queue Library

Features

At this time the library has the following adapters implemented:

dummy (does nothing)
rabbitmq (RabbitMQ)
azure-service-bus (Azure Service Bus)

Requirements

@nestjs/config package needs to be installed in the project. See: https://docs.nestjs.com/techniques/configuration

Installation

npm install --save @sclable/nestjs-queue

Setting up

Create configuration file

In the application's configuration folder there must be a file which configures the storage library. You can simply copy src/examples/queue.config.ts and remove the parts you don't need.

// config/queue.ts

import { registerAs } from '@nestjs/config'
import { QueueModuleOptions, QueueType } from '@sclable/nestjs-queue'

export default registerAs(
  'queue',
  (): QueueModuleOptions => ({
    type: (process.env.QUEUE_TYPE || QueueType.DUMMY) as QueueType,
    config: {
      [QueueType.DUMMY]: {
        enabled: true,
      },
      [QueueType.RABBITMQ]: {
        hostname: process.env.QUEUE_RABBITMQ_HOSTNAME || 'localhost',
        port: +(process.env.QUEUE_RABBITMQ_PORT || 5672),
        username: process.env.QUEUE_RABBITMQ_USERNAME || 'guest',
        password: process.env.QUEUE_RABBITMQ_PASSWORD || 'guest',
      },
      [QueueType.AZURE_SERVICE_BUS]: {
        connectionString:
          process.env.QUEUE_AZURE_SERVICE_BUS_CONNECTION_STRING ||
          'define QUEUE_AZURE_SERVICE_BUS_CONNECTION_STRING',
      },
    },
  }),
)

Add configuration to your .env file

You can remove the ones you don't need.

## QUEUE_TYPE=[dummy|rabbitmq|azure-service-bus]
QUEUE_TYPE=dummy

Import QueueModule to your application

// app/src/app.module.ts

import { Module } from '@nestjs/common'
import { ConfigService } from '@nestjs/config'
import { QueueModule, QueueModuleOptions, QueueType } from '@sclable/nestjs-queue'

@Module({
  imports: [
    // ...
    QueueModule.forRootAsync({
      useFactory: (config: ConfigService) =>
        config.get<QueueModuleOptions>('queue', {
          type: QueueType.DUMMY,
          config: {},
        }),
      inject: [ConfigService],
    }),
    // ...
  ],
})
export class AppModule {}

Adapters

Only one adapter can be used in the application, defined by the QUEUE_TYPE environment variable.

Dummy Adapter

The dumy adapter serves only testing purposes, the message is sent to the void, the listener is not getting any messages. Still the implementation is valid even if there are no queue service is running.

You need to add the following configuration to your .env file:

## QUEUE_TYPE=[dummy|rabbitmq|azure-service-bus]
QUEUE_TYPE=dummy

RabbitMQ Adapter

Uses RabbitMQ as a queue service.

To use RabbitMQ you have to install amqp-ts package to your application.

npm install --save amqp-ts

You need to add the following configuration to your .env file:

## QUEUE_TYPE=[dummy|rabbitmq|azure-service-bus]
QUEUE_TYPE=rabbitmq

QUEUE_RABBITMQ_HOSTNAME=localhost
QUEUE_RABBITMQ_PORT=5672
QUEUE_RABBITMQ_USERNAME=guest
QUEUE_RABBITMQ_PASSWORD=guest

Azure Adapter

Uses Azure Service Bus as a queue service.

To use Azure Service Bus you have to install @azure/service-bus package to your application.

npm install --save @azure/service-bus

You need to add the following configuration to your .env file:

## QUEUE_TYPE=[dummy|rabbitmq|azure-service-bus]
QUEUE_TYPE=azure-service-bus

QUEUE_AZURE_SERVICE_BUS_CONNECTION_STRING=

Usage

QueueService. Import, inject and use.

import { QUEUE_SERVICE, QueueMessage, QueueServiceContract } from '@sclable/nestjs-queue'

@Injectable()
export class SomeService {
  public constructor(
    @Inject(QUEUE_SERVICE)
    private readonly queueService: QueueServiceContract,
  ) {}

  public sendMessage<PayloadType>(
    queueName: string,
    payload: PayloadType,
  ): Promise<void> {
    return this.queueService.sendMessage<PayloadType>(queueName, payload)
  }

  public listen<PayloadType>(queueName: string): Promise<void> {
    return this.queueService.addConsumer<PayloadType>(
      queueName,
      (message: QueueMessage<PayloadType>) => {
        console.info(message)
        message.ack()
      },
    )
}

Functions

QueueServiceContract defines what one can to with the service.

export interface QueueServiceContract {
  sendMessage<PayloadType>(queueName: string, payload: PayloadType): Promise<void>
  addConsumer<PayloadType>(
    queueName: string,
    consumer: (msg: QueueMessage<PayloadType>) => Promise<void> | void,
  ): Promise<void>
}