Package Exports

nestjs-rabbitmq-retry
nestjs-rabbitmq-retry/dist/index.js

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Readme

NestJS RabbitMQ Retry

It is a library for the NestJS framework that allows easy communication with RabbitMQ and also provides an already implemented retry mechanism.

Install

npm install amqplib nestjs-rabbitmq-retry

How to use

After installing nestjs-rabbitmq-retry you need to import it globally preferably in app.module.

@Module({
  imports: [
    RabbitMQModule.forRoot({
      host: '0.0.0.0:5672',
      username: 'guest',
      password: 'guest',
      retry: 3,
      prefetch: 100,
      queues: [
        { queue: 'save', exchange: 'exchange-save', exchangeType: 'topic', routingKey: 'routing-key-save', ttl: 10000 },
        { queue: 'update', exchange: 'exchange-update', exchangeType: 'topic', routingKey: 'routing-key-update', ttl: 20000 },
      ],
    })
  ],
})
export class AppModule {}

The configuration attributes are:

host: The host where RabbitMQ is running. (Mandatory).
username: The username to access RabbitMQ. (Mandatory).
password: The password to access RabbitMQ. (Mandatory).
retry: The number of times the message will be processed. (The default value is 3).
prefetch: The amount of messages a channel will fetch at once. (The default value is 50).
queues: It is an array that indicates which queues must be created, the necessary exchanges and the routing key to carry out the calls. (The default value is an empty array).

The attributes of the queues parameter are as follows:

Name	Explanation
name	The name of the queue to be created. (Mandatory).
exchange	The name of the exchange to be created. (Mandatory).
exchangeType	The type of exchange that will be created. Possible values are: topic, direct, fanout and headers. (Mandatory).
routingKey	The name of the routing key to bind. (Mandatory).
ttl	The time in milliseconds that the message will wait to be reprocessed. (Mandatory).

Listener

To configure a queue listener is very simple, just put the Listener annotation in the method you want to process the message. In this annotation you put the name of the queue that you want to receive messages.

@Injectable()
export class SavedMediaListener {
  @Listener('save')
  listener(properties: MessageProperties, body: string) {
    console.log(properties);
    console.log(body);
  }
}

Producer

To send a message you need to use the RabbitMQService class. The required attributes are the exchange name, the routingKey and the message you want to send. You can send a message of any type.

Attention: To use this class you need to have imported the RabbitMQModule.

@Injectable()
export class MediaService {
  constructor(private rabbitmqService: RabbitMQService<string>);
  async sendMedia(): Promise<void> {
    await this.rabbitmqService.publish('exchange-save', 'routing-key-save', 'message');
  }
}