ChatHub

About The Project

Implemented a scalable full-stack chat room application that allows real-time group chat and message voting for a 3-day hackathon

Basic Features

• User account creation (sign in / sign up)
• Chat room info with online member count display
• Group chat
• Upvote/downvote or undo upvote/downvote each message (no multivoting)

Tech Stack

• Frontend: React Javascript
• Backend: Go, Gin
• Protocol: RESTful API, Websockets
• Message Queue: Redis
• Database: MongoDB
• Local Deployment: Docker
• Infrastructure: Minikube

Tech Features

• Basic password authentication and secure storage
• JSON Web Token for authentication and secure connections
• Horizontally scalable API Server and Chat Server (messaging, upvote/downvote)
• Decoupled API Server and Chat Server

Software Architecture

Note: The Load Balancer is not implemented and is only to show how the Client load can be distributed evenly among Chat Servers, since the Chat Servers are implemented to be able to horizontally scale.

User Flow

1. The Client will contact the API Server to create a new account in which the new user info will be stored in User Database.
2. The Client will then sign in and retrieve a JSON Web Token (JWT) and Chat Server's server info.
3. Client can then use the JWT and server info to authenticate and establish web socket connection with a Chat Server.
4. After the Client is connected, the Chat Server will push all the chat history to the Client through the web socket.
5. The Client can now send messages in the chat room.
6. The Chat Server will receive the message, process it, store it in Chat Database, and publish it to the Pub/Sub Redis message channel.
7. All subscribed Chat Servers will receive the message and broadcast it to all the connected Clients through web socket.
8. All online Clients can now either upvote/downvote or undo upvote/downvote the messages in the chat room.
9. The Chat Server receives the vote, update both the vote count and voter in the database, and publish the updated message.

Instruction

Local Run

Run docker containers and access at http://localhost:8080

docker compose up

Kubernetes Deployment

1. Create a minikube cluster

   minikube start

2. Point your shell to minikube's docker-daemon

   minikube docker-env
   eval $(minikube -p minikube docker-env)
   

3. Build and pull your docker images

   docker compose build
   docker compose pull
   

4. Deploy api server, chat server, mongodb, and redis into the minikube cluster

   kubectl apply -f deployment