Caching Proxy Server

A lightweight and efficient caching proxy server built with Go. This server forwards requests to a specified origin server, caches the responses, and serves subsequent identical requests from the cache. It includes a CLI for starting the server and clearing the cache.

Features

• Proxy Requests: Forwards HTTP requests to an origin server.
• Response Caching: Caches responses to identical requests for faster subsequent retrievals.
• Custom Headers:
  • X-Cache: HIT if the response is served from the cache.
  • X-Cache: MISS if the response is forwarded from the origin server.
• CLI Options:
  • Start the server with custom port and origin.
  • Clear the cache directly from the CLI.
• Concurrency: Supports multiple simultaneous requests with thread-safe caching.

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Getting Started

Prerequisites

• Go (1.19 or later)

Installation

1. Clone the repository:

   git clone https://github.com/your-username/caching-proxy.git
   cd caching-proxy

2. Build the project:

   go build -o caching-proxy ./cmd/caching-proxy

3. Verify the build:

   ./caching-proxy --help

Usage

Start the Proxy Server

Run the server with a custom port and origin URL:

./caching-proxy --port <number> --origin <url>

Example: Start the server on port 3000 and forward requests to http://dummyjson.com:

./caching-proxy --port 3000 --origin http://dummyjson.com

Behavior:

• A request to http://localhost:3000/products will forward to http://dummyjson.com/products and cache the response.

• Subsequent requests to http://localhost:3000/products will return the cached response.

Clear the Cache

Clear all cached responses without starting the server:

./caching-proxy --clear-cache

Project Structure

caching-proxy/
├── cmd/
│   └── caching-proxy/
│       └── main.go          # CLI entry point
├── internal/
│   ├── cache/
│   │   └── cache.go         # Cache implementation
│   ├── proxy/
│   │   └── server.go        # Proxy server logic
├── go.mod                   # Go module file
├── README.md                # Project documentation

How It Works

1. Request Handling:

   • The server listens on the specified port and intercepts HTTP requests.
   • For each request:
     • Cache Hit: Return the cached response with X-Cache: HIT.
     • Cache Miss: Forward the request to the origin server, cache the response, and return it with X-Cache: MISS.

2. Cache Storage:

   • Responses are cached in-memory using a thread-safe mechanism (sync.Map).
   • The cache key is constructed using the HTTP method and request URL.

3. Cache Management:

   • A ClearCache function is provided to reset the cache.

Future Enhancements

• Time-to-Live (TTL): Add support for cache expiration.
• Persistent Cache: Save cache to disk for persistence across restarts.
• Configurable Options: Allow users to configure cache size and TTL.
• HTTPS Support: Add support for forwarding secure HTTPS requests.

Contributing

Contributions are welcome! Feel free to submit issues or pull requests to improve the project.