What is a reverse proxy and through what can it be implemented?

A reverse proxy is a server that accepts requests from clients and forwards them to one or more internal servers (backend). Clients interact only with the reverse proxy, unaware of the actual servers, which allows hiding the internal infrastructure, load balancing, caching responses, and ensuring security.

Implementing a reverse proxy can be done through:

• Specialized servers and software: Nginx, HAProxy, Apache HTTP Server (with the mod_proxy module).
• Cloud services and CDNs: Cloudflare, AWS Elastic Load Balancer.
• Built-in solutions in applications, for example, in Go, you can write your own reverse proxy using the net/http package.

Example of a simple reverse proxy in Go:

package main

import (
    "log"
    "net/http"
    "net/http/httputil"
    "net/url"
)

func main() {
    target, _ := url.Parse("http://localhost:8081")
    proxy := httputil.NewSingleHostReverseProxy(target)

    http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        proxy.ServeHTTP(w, r)
    })

    log.Println("Starting reverse proxy on :8080")
    log.Fatal(http.ListenAndServe(":8080", nil))
}

This code redirects all requests from port 8080 to a server running on port 8081.