GO CDN STACK

This project implements a Content Delivery Network (CDN) system using Go (Golang) with the following stack:

• Gin (HTTP framework)
• MongoDB (Control Panel persistence)
• NATS (messaging bus for events & health checks)
• Monorepo structure with multiple services

📂 Repository Structure

.
├── control-panel       # Management API + MongoDB persistence + NATS subscriber
├── edge                # Edge CDN service (serves cached content, proxies requests)
├── mid                 # Mid-tier service (cache logic, sync with control panel, health checks)
└── origin-sample       # Sample origin server (static files for testing)

Service Breakdown

Control Panel

• REST API to manage users, CDNs, and snapshots
• Persists data in MongoDB
• Subscribes to health updates from services via NATS

Edge

• Receives client requests
• Caches static content (images, CSS, JS, fonts, video, audio)
• Proxies dynamic/non-cacheable requests to origin servers
• Stores cache on disk

Mid

• Syncs CDN configurations from control panel (via snapshot API)
• Caches responses locally (on disk + in-memory metadata)
• Publishes service health status via NATS
• Subscribes to snapshot updates from control panel

Origin Sample

• Simple static file server (images, JSON, video) for testing CDN flows

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🚀 How to Run

1. Clone the repo

git clone https://github.com/AmirAghaee/go-cdn-stack.git
cd go-cdn-stack

2. Run Control Panel

Make sure MongoDB & NATS are running.

cd control-panel
go run main.go

3. Run Mid Service

cd mid
go run main.go

4. Run Edge Service

cd edge
go run main.go

5. Run Origin Sample

cd origin-sample
go run main.go

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⚡ Development Notes

• Cache rules: Only image/*, font/*, text/css, text/javascript, application/javascript, video/*, and audio/* responses are cached.
• Non-GET requests are proxied directly to origin.
• Each cached item has metadata stored alongside the cached file (headers + expiry time).
• Mid-tier syncs CDNs from Control Panel at startup and also via NATS events.
• Health check messages are published by services and consumed by Control Panel.

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🛠️ Tech Stack

• Language: Go 1.25+
• Frameworks: Gin, NATS, MongoDB driver
• Persistence: MongoDB (control panel), Disk-based cache (edge/mid)

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📌 TODO

• Add Docker Compose for local development (MongoDB + NATS + services)
• Add unit/integration tests
• Implement cache invalidation via NATS
• Add rate limiting and logging middleware

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