Simple Rabbit MQ implementation in Node.js

 Provider App:

const express = require("express");

const app = express();

const PORT = process.env.PORT || 4001;

var channel, connection; //global variables

const amqp = require("amqplib");

app.use(express.json());

connectQueue()

app.get("/send-msg", (req, res) => {

// data to be sent

const data = {

title: "Six of Crows",

author: "Leigh Burdugo"

}

sendData(data); // pass the data to the function we defined

console.log("A message is sent to queue")

res.send("Message Sent"); //response to the API request

})

app.listen(PORT, () => console.log("Server running at port " + PORT));

async function sendData(data) {

// send data to queue

await channel.sendToQueue("MyDurableQueue",

Buffer.from(JSON.stringify(data)));

// close the channel and connection

await channel.close();

await connection.close();

}

async function connectQueue() {

try {

connection = await amqp.connect("amqp://admin:sangram@localhost:5672");

channel = await connection.createChannel()

await channel.assertQueue("MyDurableQueue")

} catch (error) {

console.log(error)

}

}

Client App:

const express = require("express");

const app = express();

const PORT = process.env.PORT || 4002;

app.use(express.json());

app.listen(PORT, () => console.log("Server running at port " + PORT));

const amqp = require("amqplib");

var channel, connection;

connectQueue() // call the connect function

async function connectQueue() {

try {

connection = await amqp.connect("amqp://admin:sangram@localhost:5672");

channel = await connection.createChannel()

await channel.assertQueue("MyDurableQueue")

channel.consume("MyDurableQueue", data => {

console.log(`${Buffer.from(data.content)}`);

channel.ack(data);

})

} catch (error) {

console.log(error);

}

}

You Need to install amqplib & express node packages.run both applications.

Here client will run on 4002 port & Provider will run on 4001 port.

Initiate Message using following API Hit from Browser or postman

http://localhost:4001/send-msg

When you hit above URL output on Provider node console is

Server running at port 4001

A message is sent to queue

and message on client node console is

Server running at port 4002

{"title":"Six of Crows","author":"Leigh Burdugo"}

and GET API Response is:

Message Sent