Caching Proxy

Caching Proxy is a program designed to proxy HTTP requests to a specified address and cache the results. The program automatically clears the cache at a specified interval and also supports manual cache clearing via a specific API endpoint.

Project idea from https://roadmap.sh/projects/caching-server

Features

• Proxy requests to another server.
• Cache responses to speed up subsequent requests.
• Automatic and manual cache clearing.
• x-cache header in the response to indicate whether the result was retrieved from the cache.

Installation and Usage

Step 1: Build the executable

Before running the program, you need to build the executable using the make build command:

make build

This will compile the program and create an executable file named caching-proxy.

Step 2: Running the program

Once the program is built, you can start the server using the following command:

./caching-proxy -port=<number> -origin=<url> -auto-clear-cache=<number>

Where:

• -port is the port the server will listen on (default: 8080).
• -origin is the target address where requests will be proxied (default: "*").
• -auto-clear-cache is the interval (in minutes) after which the cache will be cleared (default: 30).

Example

./caching-proxy -port=8081 -origin="https://api.github.com" -auto-clear-cache=10

In this example:

• The server will listen on port 8081.
• Requests will be proxied to https://api.github.com.
• The cache will automatically be cleared every 10 minutes.

Step 3: Making requests

Assuming the program is running on localhost:8081, all requests to localhost:8081/proxy/* will be proxied to the specified origin.

For example, making a GET request to:

http://localhost:8081/proxy/users/PavelNikoltsev

This will forward the request to:

https://api.github.com/users/PavelNikoltsev

Cache Behavior

Responses from proxied requests will be cached. On subsequent requests, the cached response will be used.

You can check whether a response was served from the cache by inspecting the x-cache header:

• HIT means the response was retrieved from the cache.
• MISS means the response was fetched directly from the origin server.

Manual Cache Clearing

To manually clear the cache, send a POST request to the following endpoint:

POST http://<your-server-address>/api/clear-cache

For example, if the server is running on localhost:8081:

POST http://localhost:8081/api/clear-cache

This will immediately clear all cached data.