nestjs-amqp-with-inject

Nestjs Amqp

An AMQP connection service for NestJS.

Using the AMQPlib for node package.

This package was intented to be used in execution content and provides a basic AMQPlib connection via the providers to allow developers to develop their amqp queue consumers and publishers. For microservice transport; check out the docs for rabbitMQ.

Install

$ yarn add nestjs-amqp
$ yarn add -D @types/amqplib

Basic usage

import {Module} from '@nestjs/common';
import {AmqpModule} from 'nestjs-amqp';

@Module({
  imports: [AmqpModule.forRoot({
    name: 'rabbitmq',
    hostname: 'localhost',
    port: 5672,
    username: 'test',
    password: 'test',
  })],
})
export default class AppModule {}

Advanced usage

Usage with nestjs-config

import {Module} from '@nestjs/common';
import {AmqpModule} from 'nestjs-amqp';
import {ConfigModule, ConfigService} from 'nestjs-config';
import * as path from 'path';

@Module({
  imports: [
    ConfigModule.load(path.resolve(__dirname, 'config', '**/*.ts')),
    AmqpModule.forRootAsync({
      useFactory: (config: ConfigService) => config.get('amqp'),
      inject: [ConfigService],
    }),
  ],
})
export default class AppModule {}

//src/config/amqp.ts
export default {
  name: 'rabbitmq',
  hostname: process.env.AMQP_HOST,
  port: process.env.AMQP_PORT,
  username: process.env.USERNAME,
  password: process.env.PASSWORD,
} 

Unfortunately multiple connections are unavailable when using the forRootAsync method.

Usage in custom provider

It is possible to inject the AmqpConnection in a factory of a custom provider if one needs such capability.

import { Connection as AmqpConnection } from 'amqplib';
import {ConfigService} from 'nestjs-config';
import {createConnectionToken} from 'nestjs-amqp/utils';

export const queueServiceProvider = {
    provider: 'QueueService',
    useFactory: (amqp: AmqpConnection, configService: ConfigService) => new QueueService(amqp, config.get('queue')),
    inject: [createConnectionToken('default'), ConfigService],
}

It's also possible to give your connections names, if you have done so then use the name of your connection instead of default.

Connection Decorators

import {Module} from '@nestjs/common';
import {AmqpModule} from 'nestjs-amqp';

@Module({
  imports: [AmqpModule.forRoot([
    {
      hostname: 'test:test@localhost',
    }, 
    {
      username: 'test',
      password: 'test',
      hostname: 'localhost',
      port: 5672,
      protocol: 'amqps',
      name: 'test',
    }
  ])],
})
export default class ExecutionModule {
}

import {Injectable} from '@nestjs/common';
import {InjectAmqpConnection} from 'nestjs-amqp';
import {Connection} from 'amqplib';

@Injectable()
export default class TestService {
  constructor(
    @InjectAmqpConnection('test')
    private readonly connectionTest: Connection, //gets connection with name 'test' defined in module
    @InjectAmqpConnection(0)
    private readonly connection0: Connection, //gets first defined connection without a name
  ) {}
}

Use InjectAmqpConnection without a parameter for default connection

Example publish

import {Injectable, Logger} from '@nestjs/common';
import {InjectAmqpConnection} from 'nestjs-amqp';
import {Connection} from 'amqplib';

@Injectable()
export default class TestProvider {
  constructor(
    @InjectAmqpConnection()
    private readonly amqp: Connection,
  ) {}
  async publish(message: string)  {
    await this.amqp.createChannel((err, channel) => {
      if (err != null) {
        Logger.alert(err, 'TestProvider');
      }
      channel.assertQueue('test_queue_name');
      channel.sendToQueue('test_queue_name', message);
    });
  }
}

More information and examples about amqplib can be found here.

Available Options

Name	For	Default
hostname	The host url for the connection	localhost
port	The port of the amqp host	5672
name	The name of the connection	default or the array key index [0]
retrys	The amount of retry attempts before surrender	3
retryDelay	The amount of milliseconds to wait before attempting retry	3000
protocol	The protocol for the connection	amqp
username	The username for the connection
password	The password for the connection
locale	The desired locale for error messages	en_US
frameMax	The size in bytes of the maximum frame allowed over the connection	0
heartbeat	The period of the connection heartbeat in seconds	0
vhost	What VHost shall be used	/

Testing this package

In order to test first you need to start the rabbitmq container. We've provided a docker-compose file to make this easier.

$ docker-compose up -d 
$ yarn test

Navigate to localhost:15672 for rabbitmq manager, username and password are both guest

If you're using docker-machine or a VM then change the env for HOST in the .env file or create one using the provided .env.dist file.

Future implementation

WARNING: The below examples have not been implemented

So far this package manages multiple AMQP connections using the nestjs container and injects them into other providers.
Alternatively I'd like to implement something like this:

import {Injectable} from '@nestjs/common';
import {
  AmqpConnection,
  Consume,
  Publish,
  Message,
} from 'nestjs-amqp';

@Injectable()
@AmqpConnection()
export default class MyAmqpService {
   
  @Consume("queue_name", {
    noAck: true,
  })
  async listen(@Message message) {
    console.log('Message received', message);
    
    //send a message back
    this.publish();
  }

  @Publish("queue_name")
  async publish() {
    return "Send this to 'queue queue_name'";
  }
}

Then using executable context

import { NestFactory } from '@nestjs/core';
import QueueModule, { MyAmqpService } from './queue';

async function bootstrap() {
  const app = await NestFactory.create(QueueModule);
  const event = app.get(MyAmqpService);

  await event.listen();

}
bootstrap();

process.stdin.resume();

Or something similar to the above is what I'd like to implement