The best practice for RabbitMQ consumers with NestJS and PM2 - node.js

Question

I use PM2 to handle each worker (consumer) in a separate process, e.g. ecosystem.config.js:
module.exports = {
apps: [
{
name: "Nest App",
script: "./dist/main.js",
instances: "3",
autorestart: false,
watch: true,
max_memory_restart: "1G",
exec_mode: "cluster",
env: {
NODE_ENV: "development",
},
env_production: {
NODE_ENV: "production",
},
},
{
name: "Consumer",
script: "./dist/message-queue/consumer.service.js",
instances: 1,
},
],
};
I also created a message-queue module which includes message-queue.service.ts that is used to setup the queue and publish messages, no problem with that.
My structure looks like:
src
message-queue
consumer.service.ts
message-queue.module.ts
message-queue.service.ts
The problem comes when we deal with the consumer (worker), channel consumed correctly, but I can't get any data from the database or call any model/service, my consumer.service.ts looks like:
import * as amqp from 'amqp-connection-manager';
import { Channel } from 'amqplib';
import { Constants } from '../utils/constants';
// consume messages from RabbitMQ
async function testConsumer(): Promise<void> {
const connection: amqp.AmqpConnectionManager = await amqp.connect('');
const channel: amqp.ChannelWrapper = await connection.createChannel({
setup: function (channel: Channel) {
return Promise.all([channel.prefetch(2)]);
},
});
connection.on('connect', function () {
console.log('Connected from test consumer');
});
return new Promise((resolve, reject) => {
channel.consume(Constants.MessageQueues.TEST, async function (msg) {
// parse message
// ...
});
});
}
testConsumer();
Can I query to get any data from the database, call any service (e.g. authService), or call any database model (e.g. userModel), and how?