RabbitMQ node demo

a-rabbitmq-demo.sh

#!/bin/bash

npm install 

start() {
  docker run -d --rm -p 5672:5672 rabbitmq
  echo Waiting 5 secs....
  sleep 5
}

# start rabbitmq if not running
cat < /dev/null > /dev/tcp/localhost/5672 ||  start
xterm  -geometry 96x24-0+0 -e ./task-generator.js & disown
xterm  -geometry 96x24-0-0 -e ./task-consumer.js & disown
xterm  -geometry 96x24+0+0 -e ./task-consumer.js & disown

package.json

{
  "name": "learn-rabbitmq",
  "version": "1.0.0",
  "description": "",
  "main": "task-generator.js",
  "type": "module",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "MIT",
  "dependencies": {
    "amqplib": "^0.8.0"
  }
}

task-consumer.js

#!/usr/bin/env node

import amqp from 'amqplib'

const queue = 'task_queue';
const sleep = (milliseconds) => {
  return new Promise(resolve => setTimeout(resolve, milliseconds))
}
// throws if there is an error
const connection = await amqp.connect('amqp://localhost');
const channel = await connection.createChannel();

await channel.assertQueue(queue, { durable: true });
const get = async () => {
  await channel.consume(queue, msg => {
        console.log(`Consume: ${msg.content.toString()}`)
        channel.ack(msg)
    });
  await sleep(500 * Math.random());
}

setInterval(get, 500);

task-generator.js

#!/usr/bin/env node

import amqp from 'amqplib'

const queue = 'task_queue';
const msg = process.argv.slice(2).join(' ') || "Hello World!";

// throws if there is an error
const connection = await amqp.connect('amqp://localhost');
const channel = await connection.createChannel();

await channel.assertQueue(queue, { durable: true });

const sendSync = async  () =>  {
  const toSend = `${msg} - ${Date.now()}`;
  const result = await channel.sendToQueue(queue, Buffer.from(toSend), { persistent: true });
  console.log(" Sent '%s - %s'", msg, toSend);
}

const sendAsync = () =>  {
  const toSend = `${msg} - ${Date.now()}`;
  channel.sendToQueue(queue, Buffer.from(toSend), { persistent: true });
  console.log(" Sent '%s", toSend);
}
setInterval(sendAsync , 20);

setTimeout( () => {
  connection.close();
  process.exit(0);
}, 5000);