yadwinderpaul / overseer

A simple service poller which 'oversees' the health of registered HTTP services

Overseer

A simple service poller which 'oversees' the health of registered HTTP services. The app is divide into 4 sections:

• The main application containing all business logic and APIs to the dependencies of the app
• Polling queue and workers which checks health of registered services asynchronously
• HTTP application using KoaJS, providing http APIs to the application
• Web application using ReactJS

Screenshots

Major Dependencies

• ReactJS is used as a client side framework for listing the registered services, viewing their statuses, registering new services, modifying and deleting currently registered.
• KoaJS is a lightweight wrapper over NodeJS http server which is used for providing http APIs for Overseer app
• BullMQ is a Redis based queue implementation which is used for the polling of registered services asynchronously and independently.
• PostgreSQL is used as persistence

Running and Setup on local

• Requirements:
  • NodeJS > 12, install from here
  • PostgreSQL > 9, server can be installed natively or run from the provided docker-compose.yml file
  • Redis, server can be installed natively or run from the provided docker-compose.yml file
• If using docker, run docker-compose up -d
• Create a .env file from copying from .env.example and input correct variables for your environment
• npm install
• npm run migrate up to setup the database
• npm run seed to create default user account
• npm run poller to start the health check service
• npm start to start the web server
• Open http://localhost:3000 in the browser
• Use email: [e-mail] and password: admin123 to login

Testing

The app does not have a lot of coverage. There are some unit tests added to showcase testing for server-side as well as client-side, which can be similarly added to other services and compoenents. Command for running tests: npm test