device-readings

Web API that receives and processes device readings. There is a requirement not to persist data to disk but rather store in-memory. Thus, in order to avoid possible race conditions, the web server is WEBrick instead of Puma because it's single-threaded.

• Getting Started
  • Setup
  • Run Server
  • Run Tests
  • Run Linter
• API Documentation
• Project Structure
• Possible Improvements

Getting Started

Setup

• Set your environment variables

  cp -i ./.env.template ./.env

• Install dependencies

  • Native

    bundle install

  • Docker

    docker compose build

Run Server

• Native

  bin/rails server

• Docker

  docker compose up

Run Tests

• Native

  RAILS_ENV=test bin/rspec

• Docker

  docker compose run --rm -e "RAILS_ENV=test" web bin/rspec

Run Linter

• Native

  RAILS_ENV=test bin/rubocop

• Docker

  docker compose run --rm web bin/rubocop

API Documentation

• Swagger docs are generated via rswag and can be accessed at http://localhost:3000/api-docs
• Request specs defined in spec/requests/api/v1 define the swagger definition for each endpoint
• To regenerate the swagger.yaml file, run the following command, validate the swagger docs, and commit the changes:
  • Native

  RAILS_ENV=test bin/rails rswag

  • Docker

  docker compose run --rm -e "RAILS_ENV=test" web bin/rails rswag

Project Structure

• app: controllers and forms
  • note: forms are intended validate input parameters
• bin: executables used for various tasks related to running, testing and linting
• spec: tests
  • note: requests subdirectory contains the swagger definitions for the API endpoints
• swagger: location of auto-generated swagger file used for API documentation

Possible Improvements

• Better validation of nested input parameters (e.g. timestamp and count)
  • consider using json-schema or dry-validation gems
• Optimize by using Rails cache instead of a class variable to store data in-memory
• Logging and monitoring using Sentry and Datadog
• Rate limiting
• Extract schema defined in spec/requests/api/v1/readings_spec.rb for the post request into a separate file in a spec/schemas directory