brq-cr/nestjs-rx-workers-poc

It provides a simple example of implementing node child_process API as server workers using the observable pattern with RxJS.

Description

It provides a simple example of the implementation of node child_process API as server workers using the observable pattern with RxJS.

You also can use this example as a reference for:

• To understand how to implement RxJS on server-side. 🚀
• To understand how to create a new node child process and communicate with them using observable pattern.
• A basic architecture to implement nestJS at enterprise-level applications.

THIS IS A POC. The use of child_process nodejs API It is not advisable to handle asynchrony queues (workers). If you need to run queues in NestJS I recommend the use of nestjs queues implementation for traditional architectures or use a microservices architecture based solution instead.

Project Structure Overview

    -- root
        -- src
            -- modules
                --  app
                    --  app.controller.ts // It contains the main route and service status route.
                    --  app.module.ts // Main application module.
                -- report
                    -- report.controller.ts // it contains the POST /generateMultipleIpReport controller to generate the reports.
                    -- report.module.ts
                    -- report.service.ts // it contains the worker launcher and communication. Also, it provides PROCESS_DELAY and MAX_ATTEMPTS variables configuration.
                    -- report.worker.ts // it contains the code that will be executed in the child node.
            -- main.ts // Application entry point.

Installation

$ npm install

Running the app

# development
$ npm run start

# watch mode
$ npm run start:dev

# production mode
$ npm run start:prod

Visit http://localhost:3000/api/ to see the Swagger documentation.

Testing multiple child_process feature

• If you want to change the variables for retry attempts and delay time of workers update the report.service.ts file under the report module.

• Run the application:

$ npm run start

• Open the Activity Monitor of your operative system.

• Run the following cURL instruction to make a POST call to generate a new IP report.

$ curl -d '{"ip": "8.8.8.8","reportServices": ["ipapi", "freegeoip"]}' -H "Content-Type: application/json" -X POST http://localhost:3000/generateMultipleIpReport

• Notice that for each report the system will create a new node child process to execute the task and then it will terminate the process.

$ curl -d '{"ip": "8.8.8.8","reportServices": ["ipapi", "freegeoip", "ipapi", "freegeoip", "ipapi", "freegeoip"]}' -H "Content-Type: application/json" -X POST http://localhost:3000/generateMultipleIpReport

Test

# unit tests
$ npm run test

# e2e tests
$ npm run test:e2e

# test coverage
$ npm run test:cov

Support

Nest is an MIT-licensed open source project. It can grow thanks to the sponsors and support by the amazing backers. If you'd like to join them, please read more here.

Stay in touch

• Author - Bryan Ramirez
• Framework Website - https://nestjs.com

License

Nest framework and the code of this exercise are MIT licensed.