P1 — ChatApp

Simple microservices chat application composed of an API gateway, authentication service, chat service, and Next.js client(s). This repository contains Docker-friendly services and example Next.js clients to run and develop locally or in containers.

Overview

• Purpose: Real-time chat demo built from small, focused services (auth, chat, gateway) with a Next.js frontend.
• Core services: api-gateway, auth-server, chat-server, client, client-2.
• Datastores: MongoDB for persistence (per-service db folders), Redis for chat/pubsub (see chat-server/redis).
• Orchestration: docker-compose.yml at repository root for local multi-container setup.

Architecture

• api-gateway: central entry point for frontend requests and proxying to backend services. See api-gateway/index.js.
• auth-server: user management and JWT issuance. See auth-server/index.js and controllers in auth-server/controllers.
• chat-server: handles messaging, stores chat documents in Mongo and uses Redis for pub/sub. See chat-server/index.js.
• client and client-2: Next.js frontends demonstrating integration with the gateway and backend services (each is a separate Next app). See client/src/app.

Repository layout (top-level)

• docker-compose.yml — orchestrates multi-service environment.
• api-gateway/ — gateway server code.
• auth-server/ — authentication service, routes and controllers.
• chat-server/ — chat service, message controllers and Redis helper.
• client/ — Next.js frontend application.
• client-2/ — alternative Next.js frontend (duplicate/example).

Getting started

Prerequisites

• Install Docker and Docker Compose (or Docker Desktop).
• Node.js (for running services locally without Docker).

Quick start (recommended)

1. From repository root run:

docker-compose up --build

2. Docker Compose will start the API gateway, auth and chat servers, databases, Redis, and the client(s) (if configured in docker-compose.yml). Check service logs to find assigned ports.

Run services locally (without Docker)

• Each service contains a package.json. Typical steps per service:

cd auth-server
npm install
npm run dev   # or npm start

Repeat for api-gateway, chat-server, and client (Next.js apps typically use npm run dev to start the dev server).

Environment variables

• The services expect standard environment variables for DB and auth configuration. Common names used across microservices:

• MONGO_URI — MongoDB connection string

• REDIS_URL — Redis connection endpoint

• JWT_SECRET — secret for signing JWTs

• PORT — service port override

Check each service folder for environment usage and sample values (e.g., in auth-server, chat-server, or docker-compose.yml).

Important files and references

• Gateway entry: api-gateway/index.js
• Auth entry: auth-server/index.js
• Chat entry: chat-server/index.js
• Client Next app: client/src/app/page.js

Development notes

• The repository contains two Next.js clients (client and client-2) with similar structure under src/app and shared store hooks in src/app/store.
• The chat service uses Redis for message pub/sub; ensure Redis is running when testing real-time features.
• Mongo databases are connected per-service (db/connectMongo.js). Ensure MONGO_URI points to the correct DB instance used by your environment.

Troubleshooting

• If ports conflict, stop other local services or adjust service PORT variables.
• If authentication fails, verify JWT_SECRET is consistent between api-gateway and auth-server (or the gateway verifies tokens using the same secret or public key).