Home Backend Development Golang How to implement anti-proxy in golang

How to implement anti-proxy in golang

Apr 25, 2023 am 09:11 AM

Golang is an efficient and concise programming language. Its powerful concurrency support and fast compilation speed make it widely respected in the field of network programming. A reverse proxy is a common network architecture that forwards requests to different servers to optimize network traffic and improve system performance. In this article, we will discuss how to implement reverse proxy using Golang.

  1. What is a reverse proxy?

A reverse proxy is a network architecture that forwards client requests to a backend server and then returns the response to the client. Unlike a forward proxy, a reverse proxy hides the identity of the backend server and provides some additional services to the client, such as load balancing, caching, and security enhancements.

The core of reverse proxy is load balancing. When a client initiates a request to the reverse proxy, the reverse proxy distributes the request to the most appropriate backend server to maximize network efficiency and performance. In addition, reverse proxies can reduce server load through caching and can provide features such as SSL termination and firewalls to enhance network security.

  1. Using Golang to implement reverse proxy

It is very simple to implement reverse proxy using Golang. Golang provides a standard library "net/http/httputil", which contains some useful functions and structures that can easily implement reverse proxy.

The following is a simple Golang reverse proxy example:

package main

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

func main() {
    proxy := httputil.NewSingleHostReverseProxy(&url.URL{
        Scheme: "http",
        Host:   "localhost:8080",
    })
    http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        proxy.ServeHTTP(w, r)
    })
    log.Fatal(http.ListenAndServe(":3000", nil))
}
Copy after login

In this example, we use the httputil.NewSingleHostReverseProxy function to create a reverse proxy object and forward the request to the port of the local host 8080. We then use the http.HandleFunc function to associate the handler function with the "/" path and start the reverse proxy on the local server at port 3000.

  1. Advanced configuration of reverse proxy

The reverse proxy created by the above code is very simple, but in actual applications, we may need more advanced configuration to satisfy specific needs. Here are some examples of advanced configurations for reverse proxies:

  • Load Balancing

Load balancing is one of the core functions of a reverse proxy. Golang provides some algorithms to evenly distribute requests among multiple backend servers. Here is a simple load balancing example:

package main

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

func main() {
    backends := []*url.URL{
        &url.URL{
            Scheme: "http",
            Host:   "localhost:8080",
        },
        &url.URL{
            Scheme: "http",
            Host:   "localhost:8081",
        },
        &url.URL{
            Scheme: "http",
            Host:   "localhost:8082",
        },
    }

    proxy := httputil.NewSingleHostReverseProxy(backends[0])
    proxy.Transport = &http.Transport{
        Dial: func(network, address string) (net.Conn, error) {
            return net.DialTimeout(network, address, time.Second)
        },
        MaxIdleConns:        10,
        IdleConnTimeout:     30 * time.Second,
        DisableCompression:  true,
    }

    proxy.ModifyResponse = func(r *http.Response) error {
        r.Header.Set("X-Proxy", "Golang Reverse Proxy")
        return nil
    }

    http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        i := rand.Intn(len(backends))
        proxy.URL = backends[i]
        proxy.ServeHTTP(w, r)
    })

    log.Fatal(http.ListenAndServe(":3000", nil))
}
Copy after login

In this example, we use a backends array containing three backend servers and randomly select one when a request arrives. We also set up a ModifyResponse function that adds an "X-Proxy" header to the response headers, and used a custom httputil.ReverseProxy.Transport field to allow for custom network connection properties. Finally, we have the reverse proxy server listening on local port 3000.

  • SSL Termination

SSL termination is a technology that can improve website performance and security. A reverse proxy can serve as an SSL termination point, accepting SSL requests from clients and forwarding unencrypted HTTP requests to the backend server. If your application uses SSL encryption, this technology can be a great way to reduce the load on the server. Here is a simple SSL termination example:

package main

import (
    "crypto/tls"
    "crypto/x509"
    "fmt"
    "io/ioutil"
    "log"
    "net/http"
    "net/http/httputil"
    "net/url"
)

func main() {
    cert, err := tls.LoadX509KeyPair("cert.pem", "key.pem")
    if err != nil {
        log.Fatalf("Failed to load keypair: %s", err)
    }

    certBytes, err := ioutil.ReadFile("cert.pem")
    if err != nil {
        log.Fatalf("Failed to read cert file: %s", err)
    }

    rootCAs := x509.NewCertPool()
    ok := rootCAs.AppendCertsFromPEM(certBytes)
    if !ok {
        log.Fatal("Failed to append root CA")
    }

    proxy := httputil.NewSingleHostReverseProxy(&url.URL{
        Scheme: "http",
        Host:   "localhost:8080",
    })
    proxy.Transport = &http.Transport{
        TLSClientConfig: &tls.Config{
            Certificates:       []tls.Certificate{cert},
            RootCAs:            rootCAs,
            InsecureSkipVerify: true,
        },
    }

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

    log.Fatal(http.ListenAndServeTLS(":3000", "cert.pem", "key.pem", nil))
}
Copy after login

In this example, we use the tls.LoadX509KeyPair function to load the TLS certificate and private key from the file system, and use the x509.NewCertPool function to build a root certificate pool . We then assign the loaded certificate and root certificate pool to the httputil.ReverseProxy.Transport.TLSClientConfig field to ensure a secure connection to the client. Additionally, we use the http.ListenAndServeTLS function in order to support HTTPS connections.

  • Caching

Caching is a technology that can significantly improve reverse proxy performance. A reverse proxy can cache front-end static resources, thereby reducing pressure on the server. The following is a simple caching example:

package main

import (
    "bytes"
    "fmt"
    "log"
    "net/http"
    "net/http/httputil"
    "net/url"
    "time"
)

var cache = make(map[string]*bytes.Buffer)

func main() {
    proxy := httputil.NewSingleHostReverseProxy(&url.URL{
        Scheme: "http",
        Host:   "localhost:8080",
    })

    http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        if r.Method == "GET" {
            if buf, ok := cache[r.URL.Path]; ok {
                w.Write(buf.Bytes())
                return
            }
        }

        if r.Method == "POST" || r.Method == "PUT" || r.Method == "DELETE" {
            delete(cache, r.URL.Path)
        }

        proxy.ServeHTTP(w, r)

        if r.Method == "GET" && r.Header.Get("Cache-Control") != "no-cache" {
            buf := bytes.NewBuffer(nil)
            buf.ReadFrom(w.(http.ResponseWriter))
            cache[r.URL.Path] = buf
        }
    })

    log.Fatal(http.ListenAndServe(":3000", nil))
}
Copy after login

In this example, we use a map variable cache to store cached response results. When the corresponding resource exists in the cache, we can directly return the result to the client without requesting the backend server. And we use the underlying type *bytes.Buffer of the http.ResponseWriter interface to cache the response results. Additionally, when the request method is POST, PUT, or DELETE, we delete the cache so that the updated data is fetched from the backend server. Finally, we handle whether we need to cache the response result by checking the "Cache-Control" field in the request header.

  1. Conclusion

Reverse proxy is a powerful network architecture that can significantly improve system performance and security by hiding the backend server and providing various additional services. sex. It is very simple to implement a reverse proxy using Golang. Golang provides many useful functions and structures to easily create a reverse proxy server. In this article, we introduced the basic concepts of reverse proxies and showed how to implement different configurations of advanced reverse proxies using Golang.

The above is the detailed content of How to implement anti-proxy in golang. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Go language pack import: What is the difference between underscore and without underscore? Go language pack import: What is the difference between underscore and without underscore? Mar 03, 2025 pm 05:17 PM

This article explains Go's package import mechanisms: named imports (e.g., import "fmt") and blank imports (e.g., import _ "fmt"). Named imports make package contents accessible, while blank imports only execute t

How to convert MySQL query result List into a custom structure slice in Go language? How to convert MySQL query result List into a custom structure slice in Go language? Mar 03, 2025 pm 05:18 PM

This article details efficient conversion of MySQL query results into Go struct slices. It emphasizes using database/sql's Scan method for optimal performance, avoiding manual parsing. Best practices for struct field mapping using db tags and robus

How to implement short-term information transfer between pages in the Beego framework? How to implement short-term information transfer between pages in the Beego framework? Mar 03, 2025 pm 05:22 PM

This article explains Beego's NewFlash() function for inter-page data transfer in web applications. It focuses on using NewFlash() to display temporary messages (success, error, warning) between controllers, leveraging the session mechanism. Limita

How can I define custom type constraints for generics in Go? How can I define custom type constraints for generics in Go? Mar 10, 2025 pm 03:20 PM

This article explores Go's custom type constraints for generics. It details how interfaces define minimum type requirements for generic functions, improving type safety and code reusability. The article also discusses limitations and best practices

How do I write mock objects and stubs for testing in Go? How do I write mock objects and stubs for testing in Go? Mar 10, 2025 pm 05:38 PM

This article demonstrates creating mocks and stubs in Go for unit testing. It emphasizes using interfaces, provides examples of mock implementations, and discusses best practices like keeping mocks focused and using assertion libraries. The articl

How to write files in Go language conveniently? How to write files in Go language conveniently? Mar 03, 2025 pm 05:15 PM

This article details efficient file writing in Go, comparing os.WriteFile (suitable for small files) with os.OpenFile and buffered writes (optimal for large files). It emphasizes robust error handling, using defer, and checking for specific errors.

How do you write unit tests in Go? How do you write unit tests in Go? Mar 21, 2025 pm 06:34 PM

The article discusses writing unit tests in Go, covering best practices, mocking techniques, and tools for efficient test management.

How can I use tracing tools to understand the execution flow of my Go applications? How can I use tracing tools to understand the execution flow of my Go applications? Mar 10, 2025 pm 05:36 PM

This article explores using tracing tools to analyze Go application execution flow. It discusses manual and automatic instrumentation techniques, comparing tools like Jaeger, Zipkin, and OpenTelemetry, and highlighting effective data visualization

See all articles