☁️ CloudFileStorage

A cloud-based file storage system built with .NET 9 and a microservices architecture. Users can upload, manage, and share files with fine-grained access control. The system is composed of three independent services orchestrated through an API Gateway.

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🏗️ Architecture

Client
  │
  ▼
┌─────────────────────┐
│   Ocelot API        │  (Port 5000)
│   Gateway           │  Routes all incoming requests
└──────┬──────┬───────┘
       │      │      │
       ▼      ▼      ▼
┌──────────┐ ┌────────────────┐ ┌──────────────┐
│  Auth    │ │  FileMetadata  │ │  FileStorage │
│  Service │ │  Service       │ │  Service     │
│ :5001    │ │  :5002         │ │  :5003       │
└──────────┘ └────────────────┘ └──────────────┘
   SQLite        PostgreSQL        Local Disk

Each service is independently structured following Clean Architecture principles:

ServiceName/
├── ServiceName.API/           # HTTP endpoints, middleware
├── ServiceName.Application/   # Business logic, DTOs, interfaces
├── ServiceName.Core/          # Domain models, repository interfaces
└── ServiceName.Infrastructure/ # EF Core, database, migrations

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🚀 Services

1. Authentication Service (/api/auth)

Handles user registration, login, and JWT token validation.

Method	Endpoint	Description	Auth Required
POST	/api/auth/register	Register a new user	No
POST	/api/auth/login	Login and receive a JWT token	No
POST	/api/auth/validate	Validate a JWT token	No

Features:

• Passwords are hashed with BCrypt
• Tokens are signed with HMAC-SHA256
• JWT tokens expire after 30 minutes
• Role-based claims (User / Admin) embedded in token
• Admin user is seeded automatically on startup via DbSeeder
• Uses SQLite as the database

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2. FileMetadata Service (/api/filemetadata)

Manages file metadata (name, description, owner, sharing rules) stored in PostgreSQL.

Method	Endpoint	Description	Auth Required
GET	/api/filemetadata/public	List all public files	No
GET	/api/filemetadata/myfiles	List authenticated user's own files	Yes
GET	/api/filemetadata/sharedwithme	List files shared with the user	Yes
GET	/api/filemetadata/admin	List all files (admin only)	Admin only
POST	/api/filemetadata	Create new file metadata record	Yes
PUT	/api/filemetadata/{id}	Update file metadata	Yes (owner/admin)
DELETE	/api/filemetadata/{id}	Delete file metadata	Yes (owner/admin)

Sharing Rules:

Rule	Description
Public	Accessible by anyone, no authentication needed
Private	Visible only to the owner
SharedWith	Accessible by a specific list of user IDs

Features:

• Uses AutoMapper to map between domain models and DTOs
• Custom JwtValidationMiddleware communicates with the Auth Service to validate every request
• Repository pattern with Entity Framework Core
• Permission checks ensure only owners or admins can modify/delete

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3. FileStorage Service (/api/filestorage)

Handles the physical storage of file binaries on the local disk.

Method	Endpoint	Description	Auth Required
POST	/api/filestorage/{id}	Upload a file	Yes
GET	/api/filestorage/{id}	Download a file	No
DELETE	/api/filestorage/{id}	Delete a file	Yes

Features:

• Files are stored locally in the UploadedFiles/ directory
• File is saved using the metadata ID as the filename (extension preserved)
• Supports any file type (application/octet-stream)
• Same JWT middleware as FileMetadata for authentication

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4. Ocelot API Gateway (localhost:5000)

All client requests go through the Ocelot gateway, which routes them to the appropriate downstream service.

Upstream (Client)	Downstream (Service)	Port
/api/auth/{everything}	/auth/{everything}	5001
/api/filemetadata/{everything}	/filemetadata/{everything}	5002
/api/filestorage/{everything}	/filestorage/{everything}	5003

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🛠️ Tech Stack

Technology	Usage
.NET 9	Core framework
ASP.NET Core Minimal APIs	HTTP endpoint definitions
Ocelot	API Gateway and request routing
Entity Framework Core 9	ORM for database access
SQLite	Auth service database
PostgreSQL	FileMetadata service database
BCrypt.Net	Password hashing
JWT (System.IdentityModel.Tokens.Jwt)	Authentication tokens
AutoMapper	DTO ↔ Domain model mapping
Clean Architecture	Project structure pattern

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⚙️ Getting Started

Prerequisites

• .NET 9 SDK
• PostgreSQL (for FileMetadata service)

Configuration

Authentication Service — src/Services/Authentication/Authentication.API/appsettings.json:

{
  "ConnectionStrings": {
    "DefaultConnection": "Data Source=app.db"
  },
  "Jwt": {
    "Key": "your-secret-key-here",
    "Issuer": "CloudFileStorage",
    "Audience": "CloudFileStorageUsers"
  }
}

FileMetadata Service — src/Services/FileMetadata/FileMetadata.API/appsettings.json:

{
  "ConnectionStrings": {
    "DefaultConnection": "Host=localhost;Database=filemetadata_db;Username=postgres;Password=yourpassword"
  }
}

Running the Application

Start each service in a separate terminal:

# 1. Authentication Service (port 5001)
cd src/Services/Authentication/Authentication.API
dotnet run

# 2. FileMetadata Service (port 5002)
cd src/Services/FileMetadata/FileMetadata.API
dotnet run

# 3. FileStorage Service (port 5003)
cd src/Services/FileStorage/FileStorage.API
dotnet run

# 4. API Gateway (port 5000)
cd src/ApiGateways/Ocelot.ApiGateway
dotnet run

Apply database migrations for the FileMetadata service:

cd src/Services/FileMetadata/FileMetadata.Infrastructure
dotnet ef database update

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🔐 Authentication Flow

1. Register — POST /api/auth/register with { username, email, password }
2. Login — POST /api/auth/login with { email, password } → receive JWT token
3. Use Token — Include Authorization: Bearer <token> header in all protected requests
4. Token Validation — FileMetadata and FileStorage services call the Auth Service internally to validate each token before processing requests

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📁 Solution Structure

CloudFileStorage/
├── src/
│   ├── ApiGateways/
│   │   └── Ocelot.ApiGateway/          # Ocelot routing configuration
│   ├── Infrastructure/
│   │   └── EventBus.Messages/          # Shared message contracts
│   └── Services/
│       ├── Authentication/             # Auth microservice (4 layers)
│       ├── FileMetadata/               # File metadata microservice (4 layers)
│       └── FileStorage/                # File binary storage microservice (4 layers)
└── CloudFileStorage.sln

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📄 License

This project is licensed under the GNU General Public License v3.0. See the LICENSE file for details.