nestjs-microservices

Create a proof-of-concept for a communication between services using NestJS framework.

Brief architecture overview

This API showcase consists of the following parts:

• Client - A NestJS HTTP gateway to publishes events to microservices. The client server publishes publishes mailer-send-exported-users and task-process-export-users that is beng handled in mailer and task service.
• Client Express - A very simple Express server that publishes event. The client-express is a simple server that demonstrates a way to publish and event and the task service handles the published events.
• Task service - responsible for heavy processing. The task service is a hybrid NestJS application that listens for HTTP requests and make use of connected microservices. It publishes mailer-send-processed-data event and the mailer service handles the event.
• Mailer service - responsible for sending out email messages. The mailer service is a microservice that listens to events.

Redis

You will need redis installed on your server to support the queue and the transport.

Installation

We 4 have services overall.

Client

cd client && npm install && npm run start:dev

Client ExpressJS

cd client-express && npm install && npm run dev

Task

cd task && npm install && npm run start:dev

Mailer

cd mailer && npm install && npm run start:dev

Run the applications

• First, run the services task and mailer.
• Then run the http servers either client or client-express. Access the url http://localhost:3000/send or http://localhost:3005.

References

• https://docs.nestjs.com/microservices/basics
• https://cloudnweb.dev/2019/08/implementing-redis-pub-sub-in-node-js-application