ToDo App - A microservices demo using Moleculer framework for Node.js

Technology Stack

• React.js
• Material-UI
• MongoDB
• Mongoose
• Moleculer
• Node.js
• Docker

Application architecture

Working with Moleculer makes it super easy to deploy a scalable microservices architecture. This application is built as shown in the following diagram:

All nodes are loosely coupled which means that we can deploy this application in such a way that is resilient, scalable and fault tolerant. We can spin-up as many nodes as we need per service.

Running this project in your local environment

Frontend

1. cd frontend
2. npm install
3. create file .env.development.local in the frontend directory and add the following content to this file: REACT_APP_API_URL=http://localhost:4000/api
4. npm start

Backend

1. cd backend
2. npm install
3. create directory config
4. create file dev.env inside config directory
5. Add this content to dev.env :

MONGODB_URL=<your mongo url pointing to application db> # for example: MONGODB_URL=mongodb://127.0.0.1:27017/moleculer-todoapp PORT=4000

6. go back to backend folder
7. npm run dev

To run unit tests

1. create file test.env inside config directory
2. Add following content

MONGODB_URL=<your mongo url pointing to test db> # for example: MONGODB_URL=mongodb://127.0.0.1:27017/moleculer-todoapp-test

3. Now, go back to backend folder and run npm run test

Running docker containers

The above instructions basically run the backend in a monolitic way. To run independent nodes per service, Moleculer includes a handy script that creates a docker container per service. To deploy the containers, cd into the backend folder and simply run:

npm run dc:up

This will create the needful images and build the containers. For instance, here is the output of docker ps from the live demo server of this app: