File Sharing Service

A simple file-sharing service built with Go and Cloudflare R2. Upload files and get shareable download links.

What It Does

• Upload files through a web interface
• Store files in Cloudflare R2 cloud storage
• Generate unique download links for each file
• Download links expire after 15 minutes for security

Prerequisites

• Go 1.25 or higher
• Cloudflare R2 account (free tier available)

Setup Instructions

1. Clone and Install

git clone https://github.com/heydeepakch/file-sharing-service.git
cd file-sharing-service
go mod download

2. Create R2 Bucket

1. Go to https://dash.cloudflare.com/
2. Navigate to R2
3. Click "Create Bucket" and name it (e.g., my-file-sharing)
4. Go to "Manage R2 API Tokens"
5. Create a new API token with Edit permissions
6. Save these three values:
   • Access Key ID
   • Secret Access Key
   • Endpoint URL (format: https://[account-id].r2.cloudflarestorage.com)

3. Configure Environment

Create a .env file in the project root:

R2_ACCESS_KEY=your_access_key_id
R2_SECRET_KEY=your_secret_access_key
R2_ENDPOINT=https://your-account-id.r2.cloudflarestorage.com
R2_BUCKET_NAME=my-file-sharing
PORT=8080
BASE_URL=http://localhost:8080

Replace the placeholder values with your actual R2 credentials.

4. Run the Server

go run .

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

5. Upload Files

Open your browser and go to http://localhost:8080

Supported File Types

• PDF (.pdf)
• Images (.jpg, .jpeg, .png, .gif)
• Archives (.zip)

Maximum file size: 100 MB

How It Works

Upload Process:

1. User uploads a file via web form
2. File is validated for type and size
3. File is uploaded to Cloudflare R2
4. Metadata is saved to local database (db.json)
5. User receives a download link

Download Process:

1. User clicks download link
2. Server looks up file in database
3. Server generates a temporary R2 URL (valid for 15 minutes)
4. User is redirected to download directly from R2

Project Structure

file-sharing-service/
├── main.go           # Main application and HTTP handlers
├── storage.go        # Database functions (JSON file storage)
├── cloud.go          # R2 connection configuration
├── static/
│   └── index.html    # Upload form
├── .env              # Environment variables (create this)
├── db.json           # File metadata (auto-generated)
└── go.mod            # Go dependencies

Environment Variables

Variable	Description
R2_ACCESS_KEY	Your R2 access key ID
R2_SECRET_KEY	Your R2 secret access key
R2_ENDPOINT	Your R2 endpoint URL
R2_BUCKET_NAME	Name of your R2 bucket
PORT	Server port (default: 8080)
BASE_URL	Base URL for links (default: http://localhost:8080)

API Endpoints

GET /

• Returns upload form

POST /upload

• Upload a file
• Form field: file
• Returns: Download link

GET /download/{id}

• Download a file
• Redirects to temporary R2 URL