🧩 Fullstack Microservice Realtime Chat Project

A full-stack, microservice-based Realtime Chat Application built with Angular, .NET, Redis, RabbitMQ, Worker Service, and Docker.
This project demonstrates distributed messaging, JWT-based authentication, and scalable service orchestration.

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🏗️ System Architecture

The system consists of three main components:

Layer	Project	Description
🖥️ Frontend	App.Angular	Angular client that communicates with the backend via REST APIs.
⚙️ Backend	App.Backend	ASP.NET Core Web API handling authentication, validation, message publishing, and business logic.
🔧 Worker	App.WorkerService	Background worker consuming messages from RabbitMQ and persisting them to SQL Server.

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⚡ Quick Start

1. Clone the repository

git clone https://github.com/dgnyldrm7/FullstackMicroServiceRealtimeChatProject.git cd FullstackMicroServiceRealtimeChatProject

2. Start Seq using Docker

docker run -d -e ACCEPT_EULA=Y -p 5341:80 datalust/seq

3. Run Backend (.NET API)

cd App.Backend dotnet restore dotnet run

4. Run Worker Service

cd ../App.WorkerService dotnet restore dotnet run

5. Run Angular Frontend

cd ../App.Angular npm install ng serve

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🧭 System Overview

1️⃣ Authentication Flow

• The user sends a login request to /api/auth/login.
• The backend validates the credentials.
• If valid, AccessToken and RefreshToken are generated.
• Tokens are stored in Redis, enabling JTI (JWT ID) validation.
• Middleware dynamically validates tokens for each request.

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2️⃣ Message Publishing Flow

- The Angular client sends a chat message to the backend via REST API. - The backend publishes the message to **RabbitMQ** (`chat-messages-save` queue). - **Serilog + Seq** are used for centralized logging and monitoring. - The backend performs validation using **FluentValidation** and JWT authorization.

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3️⃣ Worker Service Flow

• The Worker Service listens to the RabbitMQ chat-queue.
• Each message is validated and persisted to SQL Server.
• The worker authenticates through /apiworker/WorkerAuth/login.
• Upon success, it connects to SignalR Hub (/workerhub) to deliver messages in real-time.

🔍 Health Checks

The backend includes built-in health check endpoints to monitor service availability and connection status.

You can integrate this with:

• Docker HEALTHCHECK instructions
• Kubernetes liveness probes
• Monitoring tools like Seq, Grafana, or Azure Monitor

🩺 Accessing the Endpoint

To view health status, simply navigate to one of the following in your backend server:

• URL /healt or /healt-ui

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⚙️ Configuration

Below is the main appsettings.json structure used by the backend:

{
  "AllowedHosts": "*",
  "ConnectionStrings": {
    "DefaultConnection": "Data Source=DESKTOP-5ESD6TM\\SQLEXPRESS;Initial Catalog=RealTimeChatApp;Integrated Security=True;Encrypt=True;Trust Server Certificate=True",
    "RedisConnection": "redis-18165.c323.us-east-1-2.ec2.redns.redis-cloud.com:18165,password=<your-redis-password>,abortConnect=false"
  },
  "RabbitMQ": {
    "User": "vqnjwdew",
    "Password": "KGZj5RK3SNVr1gpdw7JZ64VYpLNvWhli",
    "Uri": "amqps://vqnjwdew:KGZj5RK3SNVr1gpdw7JZ64VYpLNvWhli@mouse.rmq5.cloudamqp.com/vqnjwdew",
    "QueueName": "chat-messages-save"
  },
  "JwtSettings": {
    "Key": "v8$2Lp9#TxG7wQz!NfYkRsDmB4VcEj1H",
    "Issuer": "MyApp",
    "Audience": "MyAppUsers",
    "AccessTokenExpireMinutes": 20,
    "RefreshTokenExpireDays": 1
  },
  "WorkerAuth": {
    "ServiceUser": "WorkerService",
    "ServiceSecret": "61884063Aa*"
  },
  "Serilog": {
    "Using": [ "Serilog.Sinks.Console", "Serilog.Sinks.Seq" ],
    "MinimumLevel": {
      "Default": "Information",
      "Override": {
        "Microsoft": "Warning",
        "System": "Warning"
      }
    },
    "Enrich": [ "FromLogContext", "WithMachineName", "WithThreadId" ],
    "WriteTo": [
      { "Name": "Console" },
      { "Name": "Seq", "Args": { "serverUrl": "http://localhost:5341" } }
    ],
    "Properties": { "Application": "RealTimeChatApp" }
  }
}