IP Reroute Middleware for Traefik

A lightweight, fast, and production-ready middleware for transparent rerouting of client requests based on IP using Redis.

This middleware allows you to reroute requests to a different backend without using redirects (302/301) and without modifying request headers, so the client remains unaware of the reroute.

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✨ Features

• ✅ Fully transparent reroute (no redirects)
• ✅ Supports both HTTP and HTTPS
• ✅ Preserves all headers, including Host
• ✅ HTTPS SNI support
• ✅ Direct Redis integration for decision-making
• ✅ High-load ready (handles thousands of RPS)
• ✅ No internal cache (real-time decisions from Redis)
• ✅ Safe Redis timeout to prevent blocking
• ✅ Reused connection pool and transport for performance
• ✅ Ready to use as a Traefik plugin

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🧠 How It Works

For each incoming request:

1. Extracts the client IP (from X-Forwarded-For or RemoteAddr)
2. Checks Redis for a key corresponding to the IP
3. If the key exists and is not expired:
   • The request is routed silently to the configured target IP/port
   • The original headers and host are preserved
4. If the key does not exist or has expired:
   • The request proceeds normally to the original backend

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⚙️ Configuration

type Config struct {
    RedisAddress string // e.g., "redis:6379"
    RerouteKey   string // e.g., "attacker_ip_"
    RerouteIP    string // target IP for reroute
    ReroutePort  string // target port
}

Example default configuration:

&Config{
    RedisAddress: "redis:6379",
    RerouteKey:   "attacker_ip_",
    RerouteIP:    "127.0.0.1",
    ReroutePort:  "443",
}

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⚡ Performance Notes

• Reuses a single httputil.ReverseProxy and http.Transport for all rerouted requests
• MaxIdleConns and MaxIdleConnsPerHost are tuned for high concurrency
• Redis timeout ensures requests do not block if Redis is slow
• Suitable for several thousand concurrent requests per second on modern servers

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🛠 Usage

Integrate this middleware into Traefik or any Go HTTP stack:

middleware, err := ipreroute.New(ctx, nextHandler, config, "ip_reroute")
if err != nil {
    log.Fatal(err)
}

http.Handle("/", middleware)

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⚠️ Notes

• This middleware does not implement any caching. All decisions are made in real-time from Redis.
• TLS verification is skipped (InsecureSkipVerify: true) for maximum transparency and simplicity. Ensure this fits your security requirements.
• Make sure your Redis instance can handle high request rates if deployed at scale.

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📝 License

MIT License

If you want, I can also write a **shorter, GitHub-friendly description with badges, setup instructions, and example Docker/Trafik usage** to make it look professional on the repo homepage.  

Do you want me to do that too?