Does Pholcus provide a built-in proxy rotation mechanism?

Pholcus is a distributed, high concurrency and powerful web crawler software written in Go language. Pholcus does not provide a built-in proxy rotation mechanism as a feature directly within the framework. However, you can implement proxy rotation manually in your Pholcus spiders by integrating proxy rotation logic into your code.

Here's a simplified example of how you might implement a proxy rotation mechanism in Go when using Pholcus:

package main

import (
    "github.com/henrylee2cn/pholcus/exec"
    "github.com/henrylee2cn/pholcus/logs"
    // Import the app that you want to use
    _ "github.com/henrylee2cn/pholcus_lib"
    // Import the web driver that you want to use
    _ "github.com/henrylee2cn/pholcus_lib/phantom"
    "math/rand"
    "time"
)

// Define a list of proxies
var proxies = []string{
    "http://proxy1:port",
    "http://proxy2:port",
    // Add more proxies as needed
}

// getRandomProxy returns a random proxy from the list
func getRandomProxy() string {
    rand.Seed(time.Now().UnixNano())
    return proxies[rand.Intn(len(proxies))]
}

func main() {
    // Set a random proxy for each request
    exec.SetProxy(getRandomProxy)

    // Run the web crawler
    exec.DefaultRun("web")
}

In this example, SetProxy function is assumed to be a part of your spider logic where you can set the proxy for each request. Since Pholcus doesn't have a built-in SetProxy function, you would need to create your own function to assign a proxy to each HTTP request based on the logic of the spider you are implementing.

Remember to replace the proxies slice with actual working proxies that you have access to. The getRandomProxy function simply returns a random proxy from the list for each request, which is a naive approach to proxy rotation. You might want to implement more sophisticated logic depending on your requirements, such as tracking the performance of each proxy, or rotating proxies in a round-robin fashion, or even using a third-party proxy rotation service.

Proxy management is an essential feature for web scrapers looking to avoid IP bans or rate limits when scraping websites that employ anti-scraping measures. While proxy rotation is not built into Pholcus, it can be added with custom code as demonstrated above.