Of course. Here is a well-structured Go project using the Fiber framework, designed as a modular monolith that can be easily broken down into microservices in the future.

This project includes two main modules, Auth and Content Management, with dependency injection, shared utility packages, and dummy implementations for a complete, runnable example.

How to Run the Project

1. Save the files: Create the directory structure and files as shown above.

2. Install dependencies: Open your terminal in the project's root directory and run:

   go mod tidy

3. Run the application:

   go run cmd/main.go

   The server will start on http://localhost:8080.

How to Use the API

You can use a tool like curl or Postman to interact with the API.

1. Register a new user:

   curl -X POST http://localhost:8080/api/v1/auth/register \ -H "Content-Type: application/json" \ -d '{"email": "creator@example.com", "password": "password123"}'

   (Note: The default role is viewer. You would need an admin endpoint to change roles.)

2. Login:

   curl -X POST http://localhost:8080/api/v1/auth/login \ -H "Content-Type: application/json" \ -d '{"email": "creator@example.com", "password": "password123"}'

   This will return a JWT token.

3. Get User Profile:

   # Replace YOUR_JWT_TOKEN with the token from the login step curl http://localhost:8080/api/v1/auth/me \ -H "Authorization: Bearer YOUR_JWT_TOKEN"
4. Request an Upload URL (Requires creator or admin role): Since the default role is viewer, this will currently fail with a 403 Forbidden error. This demonstrates the role-based access control. To make it work, you would need to manually change the user's role in the in-memory repository or implement an admin feature to do so.

Future Microservice Extraction

This modular structure makes it straightforward to extract services:

• Extracting the Auth Service:

  1. Create a new Go project.
  2. Copy the internal/auth and pkg directories into it.
  3. The main.go in the new project would only initialize and run the auth handlers.
  4. In the original monolith (now the Content service), you would remove the internal/auth code and replace calls to authService with HTTP client calls to the new Auth microservice.
• Shared Packages: The pkg directory can be published as a private Go module that both microservices can import to share common logic like JWT validation and configuration loading.