danielgospodinow / catter

Love cats and modern software systems? Here's a cat facts application which has an architecture that fits modern needs

Catter

This project aims to be a good example of how modern software systems are made. It'll demonstrate all modern best practices in software development, which includes both the architecture and the used technologies.

Architecture of the software system

Topics which are (will be) covered

• Client application with React
• Facebook and Google authentication with OpenID Connect (OAuth 2.0)
• Microservice Architecture
• REST services with Kotlin Spring Boot and with Go
• Reactive programming with Spring Webflux
• Multiple AWS services (DynamoDB, EC2, ECR, etc)
• Containerization with Docker
• Deployment with Kubernetes
• CI/CD with Jenkins
• Swagger UI for the REST APIs with proper unit testing for high code coverage
• Service Discovery with Spring Eureka
• RabbitMQ/Kafka for communication between the services
• Saga (Ochestrated/Choreographed) and Circuit Breaker patterns implemented
• Terraform modules and Helm charts for automated infrastructure

Tutorial

I plan to go through all the covered topics step-by-step in a Medium article.

Stay tuned. It'll be published here.

Screenshots

Home Screen

Login Screen

Register Screen

catter's Issues

Create a Login page in the client with Facebook login functionality

Create Terraform module for DynamoDB

Remove Facebook login and add standard login mechanism

Add K8s helm charts

Some of which include charts for the ingress controller.

Use some AWS K8s service for the deployment of the application

Add cat fact upvote and downvote

Setup database init scripts based on the gathered data in data folder

Create DB init scripts based on the information in data/, afterwards remove this folder and the JSON in it.

Dockerize Account service

Dockerize the client service

Make a global .gitignore file instead of gitignores per project

Create project structure

Setup Jenkins for CI/CD

Provide Facebook/Google/Github user login functionalities through OAuth2.0 and OpenID Connect

Use AWS DocumentDB or spin up an EC2 instance which will host a MongoDB instance

Decide two use based on the support of a reactive interface.

Provide SwaggerUI for Rating service

Create a Catter mobile application

Create Terraform modules for the AWS EKS service

Modules which include VPC, Subnets, Security Groups, EC2s, etc.

Provide a simple React client

Wire up the Rating service with an Amazon DynamoDB service instance

Fix lint errors in Account Service

Web client password validation + alert notifications

Deploy the services on an AWS EC2 instance

Add retry mechanism on database connectivity issue

When the program initially boots up, it crashes when no MongoDB is available on port 27017. Implement a retry mechanism of some sort.

Create a basic Rating service in Go (or Kotlin)

Create a meaningful README

Update architecture picture

Account service uses DynamoDB, Rating service uses MongoDB

Cat facts add functionality for authentiCATed users, lol

Implement Saga pattern

Create an architectural diagram and add it to the README

Create Register page in the web client

Dockerize the Facts service

Web client login page doesn't work in Docker container

The container must provide HTTPS environment in order to have the client Facebook login working.

Move Facebook login logic from the frontend to a new backend service user-service

Push Docker images to GitHub

Dockerize the Rating service

Timer widget, indication for fact refresh

Introduce some sort of a visual timer below the fact text to show refresh intervals in seconds (clock, countdown numbers, etc).

Web client password hashing with bcrypt

Create a simple Spring Webflux REST service with Kotlin and Gradle

Create Account service

Create a service which will store all user-related information (userid, email, names) after a successful OAuth auth operation

Find a way to use Spring Eureka or a message broker like RabbitMQ (for exercise purposes)

Book AWS ECR service and push Catter containers

Wire up the Facts service with MongoDB through the reactive Mongo driver

Link the "danielgospodinow.com" domain to the application

Create Terraform module for AWS ECR

Provide SwaggerUI for Fact service

Define the API of the rating service

Implement the Circuit Breaker pattern in each of the services

Create register and login functionality in the client

Add security concepts like password hashing, https, etc

Update go.mod file to be the whole path to the project including the URL, not just the service name

Migrate Account service from MongoDB to DynamoDB