Toy CDN :

This Go project is a simple CDN service with caching capabilities. It forwards client requests to an origin server, caches the responses locally, and serves cached responses on subsequent requests. This reduces load on the origin server and improves response times for frequently accessed resources.

Features

Proxy Server: Forwards HTTP requests from clients to a specified origin server.
Caching: Stores responses in a local cache directory to improve performance on repeated requests.
Dynamic Origin Mapping: Configurable mapping for host-based origin redirection.
Cache Expiry: No expiry is implemented in this version; entries are cached indefinitely.

Setup

Prerequisites

Go (version 1.18 or newer)
MySQL Database (optional, if needed for custom database usage)

Configuration

Origin Mapping: The originMap variable in main.go maps local hosts to specific origin servers. Adjust as needed.
```
var originMap = map[string]string{
    "localhost:9000": "http://google.com",
}
```
Cache Directory: This project uses a local ./cache directory to store cached responses. The directory is created automatically on startup if it does not exist.

Running the Server

Clone the repository and navigate to the project directory:
```
git clone <repository-url>
cd <project-directory>
```
Build and run the Go application:
```
go run main.go
```
The server listens on port 9000 by default. You can access it by navigating to http://localhost:9000.

Code Structure

main.go: Contains the main proxy server code with caching functionality.
- Functions:
  - proxy: Handles incoming requests, checks for cached responses, and proxies requests to the origin if needed.
  - cacheGet: Reads from the cache if the response is available.
  - cachePut: Writes the response to the cache.

Usage

Send HTTP requests to http://localhost:9000 or any mapped host. For example:

Sample Response

Fetching from origin: http://google.com/? Cache hit: f22be6712ce1385865805856627b5ccf Cache hit: f22be6712ce1385865805856627b5ccf Fetching from origin: http://google.com/helloworld? Fetching from origin: http://google.com/helloworld? Fetching from origin: http://google.com/helloworld? Fetching from origin: http://google.com/search?q=tes%5C&sca_esv=6bf062aa074a1fec&sxsrf=ADLYWIJrKSArIR8n3aReDsAHkEo6sO2PIg%3A1730565312892&source=hp&ei=wFQmZ_uVNK6cseMP89KNiQ8&iflsig=AL9hbdgAAAAAZyZi0MbZbmk8O1Ci7bTxWc37ouvfRS91&ved=0ahUKEwj79e6Vir6JAxUuTmwGHXNpI_EQ4dUDCBg&uact=5&oq=tes%5C&gs_lp=Egdnd3Mtd2l6IgR0ZXNcMg0QABiABBixAxhDGIoFMgoQABiABBhDGIoFMgUQABiABDIFEAAYgAQyBRAAGIAEMgUQABiABDIFEAAYgAQyBRAAGIAEMgUQABiABDIFEAAYgARImQ9QAFjUCnABeACQAQCYAWOgAcIDqgEBNbgBA8gBAPgBAZgCBqAC3wOoAgrCAgoQIxiABBgnGIoFwgIREC4YgAQYsQMY0QMYgwEYxwHCAgsQABiABBixAxiDAcICCBAuGIAEGLEDwgIFEC4YgATCAggQABiABBixA8ICBxAjGCcY6gLCAhAQLhiABBjRAxhDGMcBGIoFwgIQEAAYgAQYsQMYQxiDARiKBcICFhAuGIAEGLEDGNEDGEMYxwEYyQMYigXCAhMQLhiABBixAxjRAxhDGMcBGIoFwgILEAAYgAQYkgMYigWYAwOSBwM1LjGgB7ou&sclient=gws-wiz Cache hit: d65b27acb73d5ec7ef902f5bee88f9b0

curl http://localhost:9000/path

# README